EnigmA Amiga Run 1995 November/EnigmA AMIGA RUN 02 (1995)(G.R. Edizioni)(IT)[!][issue 1995-11][Skylink CD].iso/earcd/program/misc/fpl-v13.lha/fpl/docs/FPLuser.doc

Text File | 1995-05-25 | 150KB | 4,240 lines

                                     FPL


                                   Version
                                     11.6




                               Daniel Stenberg



                            1993-1995 by FrexxWare
















                         Generated with Heddley v1.1
                      Heddley v1.1 (C) Edd Dumbill 1994






































                                  - Page 1 -



1.    FPL Users Documentation

 FPL is Copyright © 1992-1995 by FrexxWare. Permission is granted to freely
distribute this program for non-commercial purposes only. FPL is distributed
"as is" without warranty of any kind.

 This documents the FPL language as it runs from version 11. If you happen to
use any lower version, upgrade!

-------------------------------------------------------------------------

  FPL is very similar to C. If you know C, then FPL is very fast to learn!

        Parts of the language:

     General
     Expressions
     Functions
     Keywords
     Line control
     Statements
     Strings
     Variables
     Pragmas            (New from version 8)

     Funclibs           [Amiga only]

        Subsequent information:

     About this manual
     Error messages
     Examples
     Hints and tricks
     How to reach us

-------------------------------------------------------------------------

For more information about the FPL distribution:  General information

And for programmers that want to implement FPL library support:
 FPL implementation

2.    About this manual

 This is the FPL LANGUAGE documentation. This deals with about everything that
can be said about FPL from the user's view. For information about how to
implement fpl.library in your own code, see the FPLlib.guide and fpl.doc
files.

 Many examples provided are from the FrexxEd environment, meaning that several
of the used functions in the examples are FrexxEd specific and not a part of
FPL. (FrexxEd is Copyright © 1992-1994 by FrexxWare.)

 There should be sufficient information in this manual to allow every user to
fully understand and use FPL. If it should prove unsufficent, report it!

 TECH Notes exist in some parts of the manual, explaining why I solved things
the way I did and sometimes also how.

 This documentation is written during a long time and during a lot of FPL
updates. There might still be some old version thinking in this manual, but I
hope it won't destroy your ability to create something good with FPL.

 This manual does only handle the language FPL. When FPL is used in real life,
it will always be used in a software which is host to FPL. That software will
affect FPL a lot and you should read the FPL chapters of that software's

                                  - Page 2 -
2.    About this manual

documentation closely!

3.    How to reach me

 For private matters/discussions/questions/ideas, drop me a email/netmail at
our own BBS: The Holy Grail ([phone], FidoNet 2:201/328, running
28800 bps V34), or reach me at email: [e-mail]!

 Problems concerning FPL, the library, bug reports, other FrexxWare products
or stuff like that, are dedicated to public message areas  making it possible
for everyone to share, learn and participate.

 If you have any ideas about things you'd like FPL to support, handle or run,
don't hesitate to contact me and share your visions. FPL is continuously
developing and I need feedback to know in which directions you want it to go.

 Swedish users of FPL can take advantage of the FidoNet echo mail area named
R20_FPL. Available on backbone.

 If there is enough interest shown, I will consider arranging a standard
internet mailing list for FPL discussions.

 All forthcoming updates and releases will be uploaded as fast as possible to
the public ftp site known as AmiNet. (Thanks to Mattias Axelsson for his
offering to do this on a regular basis!)

 I'm very often on IRC, using the nick name 'Bagder', meet me there!

 Source code is very much available and if you didn't get it in the package,
get in touch!

  Snail mail address:

        Daniel Stenberg
        Ankdammsgatan 36, 4tr
        S-17143 SOLNA
        Sweden

4.    General

* Every execution begins at the top of the program and interprets from
  left to right, downwards.

* All statements must be separated with a semicolon (;).

* FPL is case sensitive. That makes the following two variable names
  different:

    hello  Hello

* There is no maximum length of a script line. In fact, the entire
  program is indeed as good in one single line as in several lines.

* There is no line orientation in the language at all. Programs can be
  written in almost any way provided that you follow the syntax rules
  of the  keywords  and  functions . Whitespaces, comments and new lines
  can be inserted anywhere to make the code more appealing to you.

* Comments are allowed everywhere and are written exactly as in C and
  Arexx as well as in C++; starting with a "/*" and ending with a "*/"
  with no nesting possibilities(1):

    /* This is a comment */

  or starting with a "//" symbol and ending with a new line. Ex:

    // This is also a comment

                                  - Page 3 -
4.    General


  (Kjell, I hope you're really happy with this feature!)

  (1) - Since version 7, FPL can be made to accept nested comments.

* Continuation of string lines is written with a backslash (\)
  character followed by a newline. Ordinary statements don't need
  any continuation character at all. Just as in C... ;-) Ex:

  a=b                   /* This is a fully working statement */
   >
   c;

  b="hello\
  world";               /* Continues a string assign.*/

  output                /* Split the name and the arguments... */
  ("hi");


  /* The code below works just fine, but writing much of this */
  /* kind might make your code rather confusing! */
  output(\
  "h\
  ello\
   wor\
  ld"\
  );

  (In 'C' you can continue *EVERYTHING* by simply writing a backslash
  and continue on the next line (thanks to the preprocessor that merges
  such lines into one for the compiler). FPL cannot perform the same
  if you're not using FPL together with a preprocessor that replaces
  such sequences (such as FPP, the FrexxWare Pre Processor).)

* All identifier names (labels/functions/variables) is limited to no
  more than 64 significant characters. More characters can be used, but
  identifiers with the same 64 first characters are considered
  identical.

* Identifiers can consist of both letters, numbers and underscores
  ("_") but must not begin with a number. Letters are the 26 characters
  from a to z and the 26 characters from A to Z.

* There is no kind of unconditional jump or goto in FPL. In languages
  like this (with different local levels), goto is most frequently
  used in the wrong way and the use of it should anyhow have been very
  limited (just look at the goto function in C). FPL doesn't need any
  goto/jump keyword.

* Do not, I repeat, do not rely on undocumented features in the
  language. FPL is constantly being changed and new error checks might
  be implemented in the next release. The strange feature you may find
  working in this version, might be a sever error in the next.
  Code as stated in the manual and your FPL code will have a much
  bigger change to stay accurate even when the version number ascends.

5.    Funclibs

   Overview
   ~~~~~~~~
 To enable third party programs to add functions to already running FPL
sessions, the 'funclib' concept was invented. The inspiration source when
designing the interface was to make it work like when using shared libraries
(known as dynamic linking in some systems).

 Using this technique, all FPL programmers can take advantage of functions

                                  - Page 4 -
5.    Funclibs

that is placed in funclibs. By simply opening the funclib all its functions
will exist and can get called. Any FPL program can open any funclib.

 Funclibs could contain functions for bringing up requesters easier, for
compression procedures, for serial port communication or for file handling.
The limits are set by the funclib programmer, not by anyone else!

    How to?
    ~~~~~~~
 By opening the desired funclib with the  openlib  function, all function will
be there. There's nothing more to it than that!
  After you've called the functions you wanted the funclib for, you simply
call  closelib  which concludes access to that funclib.

 In some occasions, the host program might have already opened a funclib for
you, and then you won't need to open it and you shouldn't close it.

6.    Line Control

 I encourage the use of preprocessors together with FPL. FPL interprets the
ANSI C standard "#line" instruction as a line number/file name changer.

    #line
    =====

 A line control directive that supplies line numbers for FPL messages. It
causes the next source line to be treated as having the specified number.

 Syntax

# line { decimal_constant [ "file_name" ] }

 In order for FPL to produce meaningful references to line numbers in
preprocessed source, the preprocessor inserts #line directives where necessary
(for example, at the beginning at after the end of included text).

 A file name specification enclosed in double quotation marks can follow the
line number. If a file name is specified, FPL views the next line as part of
the specified file. If a file name is not specified, FPL views the next line
as part of the current source file.

 Note that the keyword 'line' is optional.  The directive

        # line 300

 is equivalent to

        # 300

 Example:

 On Amiga, an FPL source could be preprocessed using SAS/C 6.x by entering the
following line:

  "sc PPONLY KEEPLINES <FPL program>"

 (note that if 'KEEPLINES' isn't specified, SAS/C won't output any #line
  instructions!)

7.    Pragmas in FPL

Pragmas are specified by entering

        #pragma <keyword>

first in a line, and where the <keyword> is a compiler specific instruction.
FPL supports the following pragmas:

                                  - Page 5 -
7.    Pragmas in FPL


(NOTE: do only use the pragmas if you are very certain of what they are doing,
they alter settings done by the FPL implementor.)

 Keyword
 -------
 cache          Make FPL keep this file in memory after execution for faster
                access (it may very well do it anyway, depending on the FPL
                setup).

 nocache        Opposite to 'cache'. Make FPL to *not* keep this file in
                memory after usage, even if symbols were exported. The file
                will be loaded into memory each time it is to be used, and is
                flushed from memory when not in use.

 reread         When executing cached files, the original file might be
                changed. This pragma will force this file to be reread if
                it is changed on disk while another version is cached and
                then executed.

 noreread       The opposite to 'reread'. Force FPL to ignore if the file has
                been changed on disk or not.

8.    Variables

* There exist a few kind of variables in FPL:

  integer       - holds a 32-bit signed numerical value.
                  (maximum: 2147483647, minimum: -2147483648)
                  Declarator: `int' or `long'

  short         - holds a 16-bit signed numerical value.
                  (maximum: 32767, minimum: -32768)
                  Declarator: `short'

  char          - holds an 8-bit signed numerical value.
                  (maximum: 127, minimum: -128)
                  Declarator: `char'

  string        - holds a contiguous sequence of characters.
                  No length limit.
                  Declarator: `string'.

  Declare a varaible by using the declarator followed by the symbol name and
  an optional initial assign. Multiple declarations can be done by comma
  separating them.
  Example:

  int a;
  string b;
  int a=2;
  string foobar="ninja", foo, bar;

  Variables not assigned when declared, equals zero or zero length strings.

* FPL includes NO floating point variables at all. The secret of still
  making proper calculations is the  remainder operator .
  (Floating point numbers/expressions is expected to appear in a future FPL
  version.)

* Variables can be declared to exist in a few different ways:

  `static'      - makes the variable to be remembered until the next time
this
                  function is invoked.
  `const'       - constant variable. After the initialization assign, this
                  cannot be changed.

                                  - Page 6 -
8.    Variables

  `auto' and
  `register'    - make a varible declared as a global to exist as a non-
                  global.
  `volatile'    - volatile variables exist in C. They are written back to
                  memory each time they are changed. FPL variables are always
                  written back when changed. Implemented to make C ports
                  easier.
  `unsigned' and
  `signed'      - not currently implemented. These words are simply read and
                  ignored.

  These keywords can be used together with a declarator keyword in any
  combination. Examples:

  static int foobar;
  int auto register foobar;
  string static foobar;

* Create declarator aliases by using the keyword `typedef'. Usage:
  "typedef <declarator> <symbol>;". After such a typedef, the alternative
  declarator can be used whereever the original declarator can be used.

* Scope of FPL Identifiers

  The region where an identifier is visible in a program is referred to
  as the scope of the identifier.

  The scope of an identifier is determined by where the identifier is
  declared.

  Block scope
  -----------
    The identifier's declaration is located inside a statement
  block.  An identifier with block scope is visible from the point where
  it is declared to the closing brace (}) that ends the block.

  You can nest block visibility. A block nested inside a block can
  contain declarations that redeclare identifiers declared in the outer
  block. The new declaration of the identifier applies to the inner
  block. The original declaration is restored when program control
  returns to the outer block. An identifier from the outer block is
  visible inside inner blocks that do not redefine the variable.

  File scope
  ----------
    The identifier's declaration appears outside of any block, before the
  start of the program.
  An identifier with file scope is visible from the point where it is
  declared to the end of the source file.

  Example:

    void cool(int);
    void stupid(int);

    int a=-50;
    int b=1000;
    cool(a):
    exit;

    void cool(int a)
    {
      stupid(a);
    }

    void stupid(int a)
    {

                                  - Page 7 -
8.    Variables

      {
        int b=0;
      }
      output(b/a);
    }

* All FPL variables must be declared before use and they must be
  declared first in the block. (Blocks are always started with an
  an open brace and ended with return() or a close brace.)
  (NOTE: The technique is like the one used in common C)
  Ex:

    int a;
    for(a=0; a<10; a++) {
      int b=0;
      output(b);
    }

  is correct, but NOT this:

    char a;
    output(a);
    short b=5;  /* the line above broke the chain of declarations */

* Variables declared within loop braces will be declared and
  assigned every loop, this is anyhow not good for execution speed! Ex:

    int a;
    for(a=0; a<6; a++) {
      int b=a*2;
      output(b, ", ");
    }

  This example will output() "0, 2, 4, 6, 8, 10 " !

* Multi dimensional variable arrays are supported. To create e.g twenty
  integers:

    int hello[20];

    (These will be accessible by the names hello[n], where n is a number
    from 0 to 19.)

  or

    int hello[4][5];

    (These will be accessible by the names hello[n][m], where n is a number
    from 0 to 3, and m is a number from 0 to 4.)

* Assign arrays using the {} operators. This example assigns var[3] to
  100 and var[4] to 200:

    var[3]={100, 200};

  When declaring variables, the array assign always begins with the
  first member of the array, this line assigns the four members a[0] to
  a[3]:

    string a[4]={"hi", "how", "are", "you?"};

  The value of an array assign expression is always the last member of
  the assign list. The following example will output the word "world"
  on the screen:

    output(a[0]={"hello", "world"});


                                  - Page 8 -
8.    Variables

  Compound assigns on arrays are also valid! The following line adds 2,
  3 and 4 to the variables length[3], length[4] and length[5]:

    length[3]+={2, 3, 4};

  The value of this expression will be the last addition (length[5]+4).

  The string append operator is also array friendly. The following
  example add strings to the strings names[1] and names[2].(The
  returning string will be names[2]+=" (stupid)".):

    names[1]+={" (ill)", " (stupid)"};

  Of course, this works with array using more than one dimension too:

    int foo[2][3]={
      {0, 1, 2},
      {2, 3, 4}
    };

  On the fly, things like this can (of course) be used:

    foo[1]^={{2}, {3, 4}};

* Attempts to create a variable with a name that is already being used
  by another variable in the same local level will result in an error.

* FPL supports variable referencing, more familiar to C programmers as
  pointers to variables. Currently, though, you cannot declare or assign
  them in any other way than through the parameters of a function call:

    int foobar(int *barfoo) /* this function receives an integer reference */
    {
      *barfoo = 5; /* assign the variable 'barfoo' is referencing! */
      barfoo = 5;  /* ILLEGAL /
    }
    int ninja;
    foobar(&ninja); /* make foobar() assign the 'ninja' variable!

  The same procedure is indeed possible to perform when referencing strings.

9.    Strings

* Strings are always written enclosed within quotation marks (").

* To read the ASCII value of a single character within a string, use
  square brackets in the form: name[index] where name is the name of
  the string variable (could of course also be an array member) and
  index is the column you want to check out. Index below zero or above
  the length of the source string will result in error. The following
  example outputs all ASCII codes in a string:

     string  str = "hello world";
     int  ascii, n;
     while ( ascii = str[n++] ) {
       output ( ascii "n" );
    }

  This example will output all ASCII values in column 2 in the strings
  in the array:

     string  str[3] = {"hello", "world", "string"};
     int  n;
     for ( n = 0; n < 3; n++ ) {
       output ( str[n][2] "n" )
    }


                                  - Page 9 -
9.    Strings

  Reading beyond the end of a string simply returns a zero, while
  reading a negative column will result in an error.

* Strings not enclosed within quotes are assumed to be variable names.

  Note the difference between:

    output("Hello");

  and

    output(Hello);

  (Example 1 outputs the actual string "Hello", while example 2 outputs
  the contents of the variable *named* "Hello".)

* Append strings to a string variable by using the '+=' operator. Ex:

    string a="Hello ";
    a+="world";
    output(a);

  Outputs the string "Hello world" on the screen.

    string a = "Hello ";
    string b ="world";
    output( a + b );

* Special characters within strings should be symbolized with backslash
  and a character just as in the good old C standard:
  a    - Alert (bell)
  b    - Backspace
  f    - Form feed (new page)
  n    - New-line
  r    - Carriage return
  t    - Horizontal tab
  v    - Vertical tab
  '    - Single quotation mark
  "    - Double quotation mark
  ?    - Question mark
  \    - Backslash
  xhh  - hex number, where "hh" is a two digit hexadecimal value.
  nnn  - octal number, where "nnn" is a three digit octal value.

See also the function reference for string handling functions such as
 strcmp(), strncmp(), substr(), eval() and more.

10.    Functions

If you are not aquinted to the use/calling of functions from FPL, read the
 general function usage  paragraph.

In a standard FPL environment there is a lot of functions that the FPL
programs can use. They are added to FPL in three different ways:

* The host program of FPL adds a lot of functions so that the programs really
  can do anything fun with the software. Such functions are called "external"
  functions and they can't be described in this document but will be found in
  the host programs documentation.

*  Inside functions  that are declared and defined in an
  FPL program. Any FPL program can create a function that can be called from
  another function and that is treated and looks just like all the other
  functions.

* The  Internal functions  are supplied by FPL itself. Such functions
  will always be there, no matter what the name or the purpose of the host

                                 - Page 10 -
10.    Functions

  program is.

11.    Declare inside functions

 This chapter handles FPL function declarations and definitions. A function
declararation declares the format and existence of a function prior to its
use. A function definition defines a function.

 A function in FPL must always be declared (prototyped) or defined before it
is used. Otherwise it doesn't know where to find the function and how to
interpret its parameters.

    Function Declaration (prototyping)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 A function declaration establishes the name of the function, the type of
result that the function returns and the types of the arguments expected by
the function when you call it.

If the function does not return a value, declare it as a function returning
void.

If the function is to be accessed from other program than this, it should be
declared `export <the rest>'.

Example:

      int func (int, string);

    Function Definition
    ~~~~~~~~~~~~~~~~~~~
 A function definition specifies the name, formal parameters, and body of a
function. You must also specify the function's return type.

A function definition contains the following:

* A type specifier, which determines the type of value that
  the function returns. A function returning no value should be declared
  to return `void'. A function can have any type specifier.

* A function identifier, which provides the function with a name.

* A list of parameters that the function expects and their types.

* A block statement, which contains data definitions and code.

 A function can be called by itself or by any function that appears in the
same file as the function definition. If a function has been declared
`export'ed, the function also can be called by functions that appear in other
files, otherwise it can only be directly invoked from within the same source
file.

 The function definition or a declaration for the function must appear before,
and in the same file as, a call to the function.  All declarations for a given
function must be compatible with the function definition. They must have the
same return type and the same parameter types.

 The following example is a complete definition of the function sum:

      int sum(int x,int y)
      {
        return(x + y);
      }

 The function sum returns int, and receives two values declared as x and y.
The function body contains a single statement that returns the sum of x and
y.


                                 - Page 11 -
11.    Declare inside functions

 To indicate that a function accepts no parameters, use the keyword void as
the type specifier in place of the parameter.  For example:

      stop(void) { }

 In the following example, the function f() takes one integer parameter and
returns no value, while g() expects no parameters and returns an integer.

      void f(int); int g(void);

    Function Body
    ~~~~~~~~~~~~~
 The body of a function is a  block statement.  The following function has an
empty body:

     void stub1(void) { }

The body of the following function contains a definition for the integer
variable big_num and a call to the function  printf:

      void largest(int num1, int num2) {
         int big_num;

         if (num1 >= num2)
           big_num = num1;
         else
           big_num = num2;

         printf("big_num = %d\n", big_num);
         return 0;
      }

Block statements are described in  Statements .

* Prototypes *MUST* be first in the program. Before any program starts and
  outside all braces to be global. Prototyping within the braces of a
function
  makes the function only local accessible.

12.    General function use

 Here follows the ground rules when using/calling a function in FPL programs.

* A function call has three major parts:
  1 - The function identifier. The name of the function.
  2 - A list of parameters. Most functions demands some kind of input.
  3 - A return code from the function call.

  In the example:

                        retval = foobar ( "hello", 100 ) ;

  Reference letter:        A        B   C    D   E   F G H

  A - The variable that received the return code of the function. It must be
      be of the type that the function returns. If the function returns a
      string, the variable that receives the return code must be a string.
      A return code from a function can always be ignored. Often it is wise
      to check for progress, but it is always the choice of the programmer.

  B - The function name. We call the "foobar" function in this example.

  C - Always write the parameter list within parentheses. They tell FPL that
      this really is a function. Even functions without in any input
      parameters must be called with parentheses (but then without any
      parameters in between)!


                                 - Page 12 -
12.    General function use

  D - This is the first parameter to the function. Appearantly this function
      accepts a string type as first parameter. Any string variable or string
      expression is then a valid parameter.

  E - Separate all parameters with a comma ",".

  F - This is a second parameter. Appearantly this function accepts an
      integer type as second parameter. Any integer variable or numerical
      expression is then a valid parameter.

  G - Conclude the parameter list with a closing parenthesis. Obviously, this
      function is happy with two parameters.

  H - End of statement is as always indicated with a semicolon ";".


* Internal and external functions might have some arguments optional and some
  functions may even accept parameter lists (an optional amount of parameters
  of a certain type). All functions must always at least be called with the
  number of required arguments as declared. Refer to the software docs.


* There are four kinds of arguments possible to pass to a function :

  1. Strings - constant strings or expressions returning strings.

  2. Numeric arguments - are likewise read as  numerical expressions
     including everything true expressions consist of. An integer argument
     can be sent as any kind of "char", "int" or "short" and can be received
     by any one of those. FPL is tolerant when speaking about the mix of
     such.

  3. String variable references - pointer to a  string variable .

  4. Numeric variable references - pointer to an  integer variable .
     Just as with integer arguments, the use of the integers can be any of
     the three integer types "char", "short" and "int"/"long".


* All arguments that should be sent to and received in the function must
  be declared by comma separating "int", "string", "int *" or "string *".
  (Using "char", "short" or "long" is of course working too.)

    "int"       - sends an integer result of an expression.
    "string"    - sends a string result.
    "int *"     - sends a named integer variable.
    "string *"  - sends a named string variable.

  Sending "int *" or "string *" makes the function able to change the
  contents of the variables used in the calling function.

  All declared arguments are required. Optionals are not possible to declare.

  C programmers see the obvious inspiration programming language.

13.    Constants

  Sepcifying constants in FPL can be done in several ways.

  Numeric expression constants can be written as:

  WHAT                  HOW                             EXAMPLE
  ------------------------------------------------------------------

  * octal number        an octal number with a zero     012
                        prefix


                                 - Page 13 -
13.    Constants

  * binary number       a binary number with a "0b"     0b011010
                        prefix

  * hexadecimal number  a hexadecimal number with a     0xDEADBEEF
                        "0x" prefix

  * decimal number      a number                        129

  * ASCII code          a character within apostrophes  'a'


  String constants can also be written as:

  * octal numbers       "\nnn" where nnn is an 1-3      "\12"
                        digit octal number

  * hexadecimal numbers "\xhh" where hh is a two digit  "\xea"
                        hexdecimal number

  * a string            anything within quots           "k i ll^e(rn/injax"

14.    Blockstatement

  A block statement lets you to group any number of data definitions,
declarations, and statements into one statement.  All definitions,
declarations, and statements enclosed within a single set of braces are
treated as a single statement.  You can place a block wherever a single
statement is allowed.

  All definitions and declarations occur at the beginning of a block before
statements.  Statements must follow the definitions and declarations.  A block
is treated as a single statement.

  If you redefine a data object inside a nested block, the inner object hides
the outer object while the inner block is processed.  Defining several
variables that have the same identifier can make a program difficult to
understand and maintain.  Therefore, you should limit such redefinitions of
identifiers within nested blocks.

  If a data object is usable within a block and its identifier is not
redefined, all nested blocks can use that data object.

  Initialization of an auto or register variable occurs each time the block is
run from the beginning.  If you transfer control from one block to the middle
of another block, initializations are not always performed.  You cannot
initialize an extern variable within a block.

  Examples

The following example shows how the values of data objects change in nested
blocks:

  int main(void)
  {
     int x = 1;               /* Initialize x to 1 */
     int y = 3;

     if (y > 0)
     {
       int x = 2;           /* Initialize x to 2 */
       output("second x = ", x, "\n");
     }
     output("first x = ", x, "\n");
  }

The example produces the following output:


                                 - Page 14 -
14.    Blockstatement

  second x = 2
  first x = 1

  Two variables named x are defined in main.  The definition of x on line 5
retains storage throughout the execution of main.  However, because the
definition of x on line 10 occurs within a nested block, line 11 recognizes x
as the variable defined on line 10.  Line 13 is not part of the nested block.
Thus, line 13 recognizes x as the variable defined on line 5.

15.    Statements

  These are the statements that FPL includes:

        -  Block
        -  break
        -  continue
        -  do
        -  Expression
        -  for
        -  if
        -  Null
        -  return
        -  switch      (New from version 7)
        -  while

16.    Null statement

  The null statement performs no operation;

SYNTAX
        ;

EXAMPLE
        int i;
        for(i=0; i<100; function(i++))
          ; /* null statement */

17.    Expression statement

  Expression statements performs some kind of evaluation of expression(s).

* Statements must feature an action or cause an error.

  int a;        /***************************************/
  a++;          /* These are examples of statements    */
  a=2;          /* that include some kind of "action". */
  go(a);        /***************************************/

  2+2;          /************************************************/
  a;            /* These lines are NOT valid stand aloners      */
  (c>22)*3;     /* since they don't perform any kind of change. */
  a-14*a;       /************************************************/


  Since the release of version 10, FPL does now feature yet another ANSI C
feature:

  Expressions containing the operators &&, || or ?: can be only partly
evaluated depending on the results of the other parts. Ex, in the expression
"(a || b)" a is true, and then FPL won't execute/evaluate b. Likewise "(a &&
b)" where a is FALSE, will never reach b. Also "a=b?c:d" will reach c only if
b is true, and d only if b is false!!

18.    Keywords

Detailed information is obtained in the  keyword reference .


                                 - Page 15 -
18.    Keywords

    Summary:
    ========

* Loop statements are done very similarly as in C, using the 'for', 'while'
  or 'do' statements. They are used as in the C programming language:
  (with exception for the wonderful "else" statement in "while"... )

     do  {  statement ;}  while (  expression  )

     while  (  expression  ) {  statement ; } [  else  {  statement : } ]

     for  ( expression1 ;  expression2 ;  expression3 ) {  statement ; }

  A feature (which I've always been missing when coding C) has been
  added, and that's `else' after `while'! If the condition never goes
  true, the 'else' statement will be executed.

   continue  works 100% as in C.

   break  is like break in C, but extended with an optional level
  argument.

* Take care of exceptions just as you do in C using statements like:

   if  (  expression  ) {  statement ; } [  else  {  statement ; } ]

* Declare variables and functions by using the keywords:

   int ,  char ,  short  and  long  that all creates numerical variables.

   string  declares a string variable.

   resize  changes the size of an already existing array.

   export  tells FPL that the following global declaration
  is to be exported. Exported global symbols are accessible in any file.

   More variable declaration details .

* Exit programs or functions by using:

   exit  or  return

19.    Hints and tricks

  Since I've created FPL and know about its inner workings, I'll try to sum a
few words about what could be useful to think of when coding FPL.

    General
    =======

 Parenthesized expressions will help you from making mistakes in expressions
due to lack of operator precedence knowledge.

 Do not declare unnecessary variables or variables you don't have to use. Try
to reuse already declared ones and stay away from the nasty variable
declaration  keywords !

 Of course FPL is a perfect example of using a C programming preprocessor if
you want preprocessor features like include files, macros and such goodies.
FPL currently works perfect running preprocessed programs including the
preprocessor instruction "#line".

    Interpreting speed
    ==================

 FPL Performance philosophy is a structured programmer's nightmare coming

                                 - Page 16 -
19.    Hints and tricks

true. What is said to be ugly or even dirty coding in C, in fact often is to
prefer in FPL since it's interpreting one statement at a time.

 Do as much as you can in as few  statements  as possible is a golden rule.
Use as few function calls as possible. Try to append everything possible to
the function's argument and call it only once.

 Use  compound  and nested  variable assigns ! FPL has no compiler, which
makes statements like "a=a+2; b=b+a; function(a);" interpret MUCH slower than
"function(b+=(a+=2))" even though it might look better and be more readable.
(If it was hard to code it should be hard to read, right?)

 Avoid long and complicated  string handlings . If you must use a string, try
putting it in a variable and refer to that variable as much as possible.
Especially loops will benefit a *LOT* in speed. Future version of FPL might
deal with static strings (non-variable referenced) in a better way.

    Bug hunting
    ===========

  Of course even FPL routines will be coded incorrect from time to time.

 Comment your code. It's not hard, decreases performance only slightly and
makes it so very much easier to change the code. And who knows, perhaps
someone else would want to change it in the future!

 Wait for the soon appearing FPL debugger!

20.    Numeric expressions (and operators)

  Numeric expressions are a basic part of FPL programs. Expressions are
evaluated on the basis of the operators that the expressions contain and the
contexts where the expressions can be used.

     Constants                Not changing values

     Grouping and evaluating  Precedence, associativity, etc

     Primary Expressions      Parentheses, function calls
     Unary Expressions        ++, --, +, -, !, ~
     Binary Expressions       (*, /, %, +, -, <<, >>, <, >, <=, >=, ==, etc)
     Assignment expressions   (+=, -=, *=, /=, %=, etc)
     Conditional Expressions  (?, :)
     Comma expressions        (,)

21.    Grouping and evaluating

 Two operator characteristics determine how operands group with operators:
precedence and associativity. Precedence provides a priority system for
grouping different types of operators with their operands. Associativity
provides a left-to-right order for grouping operands to operators that have
the same precedence.

 You can explicitly state the grouping of operands with operators by using
parentheses.

 In the expression

 a + b * c / d

 the * and / operations are evaluated before + because of precedence. b is
multiplied by c before it is divided by d because of associativity.

 The following table lists the FPL language operators in their order of
precedence. The operators are listed in order of precedence:  primary
operators have the highest precedence, and the  comma operator  has the lowest
precedence. Operators that appear in the same group have the same precedence.

                                 - Page 17 -
21.    Grouping and evaluating


 FPL's operator precedence is 100% ANSI C compatible.

    Operator Precedence and Associativity (decreasing order):
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    Operator Type           Associativity   Operators
    -------------           -------------   ---------
     Primary               left to right   (), function calls
     Unary                 right to left   ++ -- - + ! ~ []
     Multiplicative        left to right   * / %
     Additive              left to right   + -
     Bitwise Shift         left to right   << >>
     Relational            left to right   < > <= >=
     Equality              left to right   == !=
     Bitwise Logical AND   left to right   &
     Bitwise Exclusive OR  left to right   ^
     Bitwise Inclusive OR  left to right   |
     Logical AND           left to right   &&
     Logical OR            left to right   ||
     Conditional           right to left   ? :
     Assignment            right to left   = += -= *= /= <<= &= ^= |= >>=
     Comma                 left to right   ,


 The order of evaluation for the operands of the logical AND (&&) and the
logical OR (||) operators is always left-to-right. If the operand on the left
side of a && operator evaluates to 0 (zero), the operator on the right side is
not evaluated. If the operand on the left side of a || operator evaluates to
nonzero, the operator on the right side is not evaluated.


    Examples

The parentheses in the following expressions explicitly show how FPL groups
operands and operators:

    total = (4 + (5 * 3));
    total = (((8 * 5) / 10) / 3);
    total = (10 + (5/3));

 FPL group operands with operators that are both associative and commutative
in a simple left-to-right order. We group the operands and operators of the
expression

    total = price + prov_tax + city_tax;

in the following way (as indicated by parentheses):

    total = ((price + prov_tax) + city_tax);

 TECH NOTE:
 ~~~~~~~~~~
 In C, the example above could have been evaluated the following ways too
    total = ((price + city_tax) + prov_tax);
    total = (price + (prov_tax + city_tax));

 But that's not too good if you want to use expressions like
    a = b++ + (b>10?10:20);
 since you wouldn't know in which order the b variable is read and used... FPL
reads and uses it in a left-to-right order.

22.    Primary expressions

 All primary operators have the same precedence and have left-to-right
associativity. See  Grouping and Evaluating FPL Expressions


                                 - Page 18 -
22.    Primary expressions

 For detailed information on primary operators, see

     Parenthesized Expressions
     Function calls

23.    Parenthesized Expressions

 You can use parentheses to explicitly state how operands group with
operators. The following expression does not contain any parentheses used for
grouping operands and operators. The parentheses surrounding weight and
zipcode form a function call. Notice how FPL groups the operands and operators
in this expression:

 Expression without Parentheses:

       -discount * item + handling(weight, zipcode) > 10 * item

 The following expression is similar, but contains parentheses that change how
the operands and operators are grouped:

 Expression with Parentheses:

      (-discount * (item + handling(weight, zipcode))) > (10 * item)

24.    Function calls

 A function call is a primary expression followed by a parenthesized argument
list. The argument list can contain any number of expressions separated by
commas, or it can be empty.

 For example:

      stub()

      overdue(account, date, amount)

      notify(name, (date+5))

      report(error, time, date, (num++))

 The arguments are evaluated, and each parameter is assigned the value of the
corresponding argument. Assigning a value to a parameter changes the value
with in the function, but has no effect on the argument.

25.    Unary Expression


 An unary expression contains one operand of scalar type and an unary
operator. All unary operators have the same  precedence . As indicated in the
following descriptions, the usual arithmetic conversions are performed on the
operands of most unary expressions.

      Bitwise Negation ~
      Decrement --
      Increment ++
      Logical Negation !
      Unary Minus -
      Unary Plus +

26.    Increment ++

 The ++ (increment) operator adds 1 (one) to the value of the operand. The
operand receives the result of the increment operation.

 You can place the ++ before or after the operand. If the ++ appears before
the operand, the operand is incremented; then the incremented value is used in
the expression. If you place the ++ after the operand, the current value of

                                 - Page 19 -
26.    Increment ++

the operand is used in the expression; then the operand is incremented. For
example:

      play = ++play1 + play2++;

 is equivalent to the following sequence of expressions:

      play1 = play1 + 1;
      play = play1 + play2;
      play2 = play2 + 1;

 In the C language they say "avoid using a variable more than once in an
expression where the variable is incremented". But that's not necessary in
FPL! I've created it to work as I wanted it, and so it does...

      y = x(i) + i++;

Does work exactly as you think; first calls the function x(), adds the value
of i and finally increases i.

27.    Decrement --

Acts as the  ++ operator , but instead of adding it's subtracting!

28.    Unary plus +

The + (unary plus) operator maintains the value of the operand.

The result of applying the unary plus operator to a signed operand is
equivalent to the promoted type of the operand.

29.    Unary minus -

The - (unary minus) operator negates the value of the operand.

The result of applying the unary minus operator to a signed operand is
equivalent to the negative promoted type of the operand.

For example, if quality has the value 100, then -quality has the value -100.

30.    Logical negation !

The ! (logical negation) operator determines whether the operand evaluates to
0 (false). If so, the operation yields the value 1 (true). If the expression
evaluates to a nonzero value, the operation yields the value 0 (false).

If right is not equal to 0, the following two expressions are equivalent:

  !right;
  right == 0;

31.    Bitwise negation ~

The ~ (bitwise negation) operator yields the ones complement of the operand.
In the binary representation of the result, every bit has the opposite value
of the same bit in the operand.

Suppose x represents the decimal value 5. The 32-bit binary representation of
x is:

00000000000000000000000000000101

The expression ~x yields the following result, represented here as a 32-bit
binary number:

11111111111111111111111111111010


                                 - Page 20 -
31.    Bitwise negation ~

The 32-bit binary representation of ~0 is:

11111111111111111111111111111111

32.    Binary expressions

 A binary expression contains two operands separated by one operator.

 Not all binary operators have the same  precedence .

 To ensure correct results, avoid creating expressions that depend on the
order in which FPL evaluates the operands.

     Addition +
     Bitwise AND &
     Bitwise Exclusive OR ^
     Bitwise Inclusive OR |
     Bitwise Shift << >>
     Division /
     Equality == !=
     Logical AND &&
     Logical OR ||
     Multiplication *
     Relational < > <= >=
     Remainder %
     Subtraction -

33.    Multiplication *

The * (multiplication) operator yields the product of its operands.

Because multiplication has both associative and commutative properties, the
operands will be grouped in a left-to-right order. For example, the
expression:

  sites * number * cost

is interpreted in  the following way:

  (sites * number) * cost

34.    Division /

The / (division) operator yields the quotient of its operands.

If both operands are positive integers and the operation produces a remainder,
FPL ignores the remainder. Thus, the expression 7 / 4 yields the value 1
(rather than 1.75 or 2).

The C language does not define how the compiler treats the quotient when
either of the operands has a negative value.  Thus, -7 / 4 can yield either -1
or -2. However, on all IBM C compilers, -7 / 4 always results in a quotient of
-1 and a  remainder  of -3, and that's the rule FPL has been following.

It ends up in an error message if the second operand (the denominator)
evaluates to 0 (zero).

35.    Remainder %

The % (remainder) operator yields the remainder from the  division  of the
left operand by the right operand. For example, the expression 5 % 3 yields
2.

If the right operand evaluates to 0 (zero), it results in an error message. If
either operand has a negative value, the result is such that the following
expression always yields the value of a if b is not 0 (zero):


                                 - Page 21 -
35.    Remainder %

  ( a / b ) * b + a % b;

36.    Addition +

The + (addition) operator yields the sum of its operands.

37.    Subtraction -

The - (subtraction) operator yields the difference of its operands.

38.    Bitwise left and right shift << >>

The bitwise shift operators move the bit values of a binary object. The left
operand specifies the value to be shifted. The right operand specifies the
number of positions that the bits in the value are to be shifted.

The << (bitwise left shift) operator indicates the bits are to be shifted to
the left. The >> (bitwise right shift) operator indicates the bits are to be
shifted to the right.

The right operand should not have a negative value or a value that is greater
than the width in bits of the expression being shifted. Bitwise shifts on such
values give unpredictable results.

If the right operand has the value 0 (zero), the result is the value of the
left operand (after the usual arithmetic conversions).

The << operator fills vacated bits with zeros. For example, if l_op has the
value 4019, the bit pattern (in 32-bit format) of l_op is:

00000000000000000000111110110011

The expression l_op << 3 yields:

00000000000000000111110110011000

The result is the integral part of the quotient of the left operand divided by
the quantity, 2 raised to the power of the right operand. If the left operand
has a negative value, the vacated bits of a signed value are filled with a
copy of the sign bit of the unshifted value. For example, if l_op has the
value -25, the bit pattern (in 32-bit format) of l_op is:

11111111111111111111111111100111

Vacated bits are filled with ones, and the expression l_op >> 3 yields:

11111111111111111111111111111100

39.    Relational < > <= >=

The relational operators compare two operands for the validity of a
relationship. If the relationship stated by the operator is true, the value of
the result is 1 (one). Otherwise, the value of the result is 0 (zero).

FPL has the following relational operators:

Operator        Usage

<       Indicates whether the value of the left operand is less than
        the value of the right operand.

>       Indicates whether the value of the left operand is greater than
        the value of the right operand.

<=      Indicates whether the value of the left operand is less than or
        equal to the value of the right operand.


                                 - Page 22 -
39.    Relational < > <= >=

>=      Indicates whether the value of the left operand is greater than
        or equal to the value of the right operand.

Relational operators have also left-to-right associativity. Therefore, the
expression:

  a < b <= c

is interpreted as:

  (a < b) <= c

If the value of a is less than the value of b, the first relationship is true
and yields the value 1 (one).  The value 1 (one) is then compared with the
value of c.

40.    Equality == !=

The equality operators, like the relational operators, compare two operands
for the validity of a relationship. The equality operators, however, have a
lower precedence than the relational operators. If the relationship stated by
an equality operator is true, the value of the result is 1 (one). Otherwise,
the value of the result is 0 (zero).

FPL has the following equality operators:

Operator        Usage

==      Indicates whether the value of the left operand is equal to the
        value of the right operand.

!=      Indicates whether the value of the left operand is not equal to
        the value of the right operand.

The following expressions contain examples of equality and relational
operators:

  time < max_time == status < complete
  hello != world

41.    Bitwise AND &

The & (bitwise AND) operator compares each bit of its first operand to the
corresponding bit of the second operand. If both bits are 1's, the
corresponding bit of the result is set to 1. Otherwise, it sets the
corresponding result bit to 0.

The following example shows the values of a, b, and the result of a & b
represented as 32-bit binary numbers:

bit pattern of a        00000000000000000000000001011100

bit pattern of b        00000000000000000000000000101110

bit pattern of a & b    00000000000000000000000000001100

42.    Bitwise Exclusive OR ^

The ^ (bitwise exclusive OR) operator compares each bit of its first operand
to the corresponding bit of the second operand. If both bits are 1's or both
bits are 0's, the corresponding bit of the result is set to 0. Otherwise, this
operator sets the corresponding result bit to 1.

The following example shows the values of a, b, and the result of a ^ b
represented as 32-bit binary numbers:

bit pattern of a        00000000000000000000000001011100

                                 - Page 23 -
42.    Bitwise Exclusive OR ^


bit pattern of b        00000000000000000000000000101110

bit pattern of a^b      00000000000000000000000001110010

43.    Bitwise inclusive OR |

The | (bitwise inclusive OR) operator compares the values (in binary format)
of each operand and yields a value whose bit pattern shows which bits in
either of the operands has the value 1 (one). If both of the bits are 0
(zero), the result of the comparison is 0 (zero); otherwise, the result is 1
(one).

The following example shows the values of a, b, and the result of a | b
represented as 32-bit binary numbers:

bit pattern of a        00000000000000000000000001011100

bit pattern of b        00000000000000000000000000101110

bit pattern of a | b    00000000000000000000000001111110

44.    Logical AND &&

 The && (logical AND) operator indicates whether both operands have a nonzero
value. If both operands have nonzero values, the result has the value 1 (one).
Otherwise, the result has the value 0 (zero).

 The following examples show how the language evaluates expressions that
contain the logical AND operator:

 Expression      Result
 ~~~~~~~~~~      ~~~~~~
 1 && 0          0

 1 && 4          1

 0 && 0          0


 Expressions like "a && b" will only evaluate b if a is false!


NOTE: The logical AND (&&) should not be confused with the bitwise AND (&)
operator.  For example,

  1 && 4 evaluates to 1

while

  1 & 4 evaluates to 0

45.    Logical OR ||

 The || (logical OR) operator indicates whether either operand has a nonzero
value. If either operand has a nonzero value, the result has the value 1
(one). Otherwise, the result has the value 0 (zero).

 The following examples show how expressions that contain the logical OR
operator are evaluated:

 Expression      Result
 ~~~~~~~~~~      ~~~~~~
 1 || 0          1

 1 || 4          1


                                 - Page 24 -
45.    Logical OR ||

 0 || 0          0


Expressions like "a || b" will only reach b if a is false.


NOTE: The logical OR (||) should not be confused with the bitwise OR (|)
operator. For example,

  1 || 4 evaluates to 1

while

  1 | 4 evaluates to 5

46.    Conditional expressions


 (operand1?operand2:operand3)

 A conditional expression is a compound expression that contains a condition
(operand1), an expression to be evaluated if the condition has a nonzero value
(operand2), and an expression to be evaluated if the condition has the value 0
(zero) (operand3).

 The conditional expression contains one two-part operator. The ? symbol
follows the condition, and the : symbol appears between the two action
expressions. All expressions between the operators ? and : are treated as one
expression.

    Examples
    ~~~~~~~~
 The following expression determines which variable has the greater value, y
or z, and assigns the greater value to the variable x:

      x = (y > z) ? y : z;

 The following is an equivalent expression:

      if (y > z) {
        x = y;
      } else {
        x = z;
      }

 The following expression assigns an integer. If the variable c is less than
zero, output receives the value of c. If not, output receives the return code
from the search function.

      c = c<0?c:search("hello");

 If the last operand of a conditional expression contains an assignment
operator, use parentheses to ensure the expression evaluates properly. For
example, the = operator has higher precedence than the ?: operator in the
following expression:

      (i == 7) ? j ++ : k = j;

 This expression generates an error because it is interpreted as if it were
parenthesized this way:

      ((i == 7) ? j ++ : k) = j;

 That is, k is treated as the third operand, not the entire assignment
expression k = j.  The error arises because a conditional expression is not an
lvalue, and the assignment is not valid.


                                 - Page 25 -
46.    Conditional expressions

 To make the expression evaluate correctly, enclose the last operand in
parentheses:

      (i == 7) ? j ++ : (k = j);

47.    Assignment expressions

 An assignment expression gives a value to the left operand.

 The left operand in all assignment expressions must be a variable. The value
of the expression is the value of the left operand after the assignment is
completed.

 The language contains two types of assignment operators,  simple assignment
and  compound assignment  operators.

48.    Simple assignment =

 The simple assignment operator gives the value of the right operand to the
left operand.

 The following example assigns in order the value 0 (zero) to strangeness, the
value of strangeness to charm, the value of charm to beauty, and the value of
beauty to truth:

    truth = beauty = charm = strangeness = 0;

49.    Compound assignment

 The compound assignment operators perform an operation on both operands and
give the result of that operation to the left operand.

 The following table lists the compound assignment operators and shows an
expression using each operator:

 Operator        Example                 Equivalent Expression
 --------        -------                 ---------------------
 +=              index   +=  2           index   = index + 2
 -=              balance -=  debit       balance = balance - debit
 *=              bonus   *=  increase    bonus   = bonus * increase
 /=              time    /=  hours       time    = time / hours
 %=              allow   %=  1000        allow   = allow % 1000
 <<=             result  <<= num         result  = result << num
 >>=             form    >>= 1           form    = form >> 1
 &=              mask    &=  2           mask    = mask &  2
 ^=              test    ^= pre_test     test    = test ^ pre_test
 |=              flag    |=  on          flag    = flag | on


 Although the equivalent expression column shows the left operands (from the
example column) evaluated twice, the left operand is evaluated only once.

Note that the expression

    a *= b + c

is equivalent to

    a = a * (b + c)

and NOT

    a = a * b + c.

50.    Comma expressions

 A comma expression contains two operands separated by a comma operator.

                                 - Page 26 -
50.    Comma expressions

Although both operands are evaluated, the value of the right operand is the
value of the expression. The left operand is evaluated, possibly producing
side effects, and then the value is discarded.

 In the following example, if omega has the value 11, the expression
increments delta and assigns the value 3 to alpha:

      alpha = (delta++, omega % 4);

 Any number of expressions separated by commas can form a single expression.
The leftmost expression is evaluated first. The value of the rightmost
expression becomes the value of the entire expression. For example, the value
of the expression

      intensity++, shade * increment, rotate(direction);

is the value of the expression

      rotate(direction);

Restrictions

 You can place comma expressions within lists that contain commas (for
example, argument lists and initializer lists). However, because the comma has
a special meaning, you must place parentheses around comma expressions in
these lists. The comma expression t = 3, t + 2 is contained in the following
function call:

      f(a, (t = 3, t + 2), c);

The arguments to the function f are: the value of a, the value 5, and the
value of c.

51.    Keywords

 FPL supplies a number of keywords that'll help executing the program. (You
might recognize several of them from the C programming language, but please
read the descriptions carefully cause some of the keywords behave in a
slightly different way in FPL.)

 These keywords are e.g looping  functions  and conditional checks etc. The
"arguments" to these keywords are a bit special and tricky, they are therefore
not included in this table. Refer to keyword reference for proper syntax.

  Keyword        Short Description
  --------       -----------
   auto          No global variable.
   break         Break out of a number of levels of loop braces.
   case          Used in switch() statements for a specific case.
   char          Create a 8-bit signed numerical variable.
   const         Constant variable.
   continue      Continue the loop.
   debug         Control debug mode.
   default       Specifies default action in a switch() statement.
   do            do {statement} while (expression);
   exit          Stop executing this FPL routine.
   for           for(statement1;statement2;statement3)
   if            if(condition) {statement} [else {statement}]
   int           Creates an 32-bit integer variable.
   long          Equivalent to `int'.
   register      No global variable.
   resize        Resize a variable array.
   return        Return from subroutine.
   short         Create a 16-bit signed numerical variable.
   static        Remember local variables between invokes.
   string        Creates a string variable named [name].
   switch        Do different actions on different results.

                                 - Page 27 -
51.    Keywords

   typedef       Make declarator aliases.
   volatile      FPL variables are always volatile.
   while         while(condition) {statement} [else {statement}]

These keywords are reserved for FPL use, but do nothing today:

  'double'     Not implemented.
  'enum'       Not implemented.
  'float'      Not implemented.
  'signed'     ALL variables are always signed.
  'struct'     Not implemented.
  'union'      Not implemented.
  'unsigned'   Not implemented.

52.    break

SYNTAX  break [expression];

DESCRIPTION
        A break statement enables you to end iterative (do, for, while,
        switch statements and exit from them at any point other than the
        logical end.

        The break statement ends the loop or switch and moves control to the
        next statement outside the loop/switch. Within nested statements,
        break ends only the smallest enclosing do, for, while or switch
        statement as default.

        The possible "else" statement after a while, is *NOT* a loop.

        Specifying a following expression breaks out of a number of iterative
        statements.

RESTRICTIONS
        Place a break statement only in the body of an iterative statement.

EXAMPLES

        The following example shows a break statement in the action part of a
        for statement. If the i*3 is equal to 9, the break statement causes
        the for statement to end.

          for (i = 0; i < 5; i++) {
            if (i*3 == 9)
              break;
            length++;
          }

        Break out of a number of loops by giving an argument:

          for(i = 0; i < 5 ; i++) {
            for(j = 0; j < 5 ; j++) {
              if(i*5+j>18) {
                break 2; // Breaks out of two `for' loops!
              }
            }
          }

        Break out of a switch() statement:

          switch(i) {
            case 2:
              break;

            default:
          }


                                 - Page 28 -
52.    break

SEE      do ,  for ,  while ,  switch

53.    case

SYNTAX  case expression: statement;

DESCRIPTION
        The 'case' statement can only be used within a switch statement. It
        tells that the following statements should be run if the result of
        the case expression is the result of the switch expression.

        The expression must be followed by a colon ':'.

        Break the case statement with a 'break'. Then the execution will
        continue after the switch() statement.

NOTE
        If the expression contains a colon ':', it must be with parentheses
        or it can confuse the interpreter under certain conditions.

EXAMPLE
        The following program show a switch() statement with three cases:

          switch( Character() ) {
            case '\t':
            case ' ':
              a = 0;
              break;

            case '\n':
              a = -1;
              break;

            default:
              a = 1;
              break;
          }

SEE ALSO
         switch ,  break ,  default

54.    char

SYNTAX  char name [= expression];

DESCRIPTION
        Declares a char (signed 8-bit) variable (and assign a value to it).
        Read more about it the chapter discussing variables. Not assigned
        variables equals zero (0) after declaration.

INPUTS  string name     - The variable name.
        char expression - Initial expression.

SEE      int
         short
         string

55.    continue

SYNTAX  continue;

DESCRIPTION
        A continue statement enables you to stop the current iteration of a
        loop. Program control is passed from the location in the body of the
        loop where the continue is found, to the condition part of the loop.

        The continue statement ends the execution of the action part of a do,

                                 - Page 29 -
55.    continue

        for, or while statement and moves control to the condition part of
        the statement. If the iterative statement is a for statement, control
        moves to the third expression in the condition part of the statement,
        then to the second expression (the test) in the condition part of the
        statement.

        Within nested statements, the continue statement ends only the
        current iteration of the do, for or while statement immediately
        enclosing it.

RESTRICTIONS
        Place a continue statement only within the body of an iterative
        statement.

EXAMPLES
        The following example shows a continue statement in a for statement.
        The continue statement causes the system to skip over those elements
        of the formula that have values less than or equal to 100.

          output("Try this calculation while <=100.\n");
          for (i = 0; i < 10000; i++) {
            if (i*(3-b/c+a) <= 100)
              continue;
            output("The number ", i, " makes it no longer below!");
          }

SEE      do ,  for ,  while

56.    default

SYNTAX  default: statement;

DESCRIPTION
        The 'default' statement can only be used within a switch statement.
        It tells that the following statements is the default action if no
        case expressions match the switch expression.

        The keyword must be followed by a colon ':'.

        Break the default statement with a 'break'. Then the execution will
        continue after the switch() statement.

EXAMPLE
        This program executes the 'default' statement if 'x' does not match
        "foo" or "bar":

          switch(x) {
            case "foo":         /* if x is "foo" */
            case "bar":         /* if x is "bar" */
              /* nananana */
              break;            /* break out of switch */

            default:
              foobar();         /* if x isn't "foo" or "bar" */
              break;
          }

SEE ALSO
         switch ,  break ,  case

57.    do

SYNTAX  do statement; while ( expression ) ;

DESCRIPTION
        A do statement repeatedly executes a statement until a test
        expression evaluates to 0 (zero). Because of this order of

                                 - Page 30 -
57.    do

        processing, the statement is processed at least once.

        The body of the loop is run before the controlling while clause is
        evaluated. Further processing of the do statement depends on the
        value of the while clause. If the while clause does not evaluate to
        0 (zero), the statement runs again. Otherwise, processing of the
        statement ends.

        A break or return statement can cause the processing of a do
        statement to end, even when the while clause does not evaluate to 0
        (zero).

EXAMPLES
        The following statement prompts the system user to enter a 1. If the
        system user enters a 1, the statement ends execution.  If not, the
        statement displays another prompt.

          do {
            input("Enter a 1!", reply);
          } while (reply != 1);

SEE      break ,  continue ,  return

58.    debug

SYNTAX  int debug ( Enable );                                   (V9)

DESCRIPTION
         Toggles the "debug mode" state. When FPL runs in the "debug mode",
        the debugger is capable of tracing the FPL executions.

         If called without parameter, it will return the current "debug mode"
        status.

NOTE
        The FPL debugger is not extensively used, developed or spread. Much
        more documentation regarding this function and FPL debugging concepts
        and procedures will appear in future versions of this document.

INPUTS
        int Enable      - Zero to disable, non-zero to enable.

RETURNS
        It returns the "debug mode" state that was when the function was
        called. That is, if you enable debug mode, it will return the state
        previous to this function call.

SEE

59.    else

SYNTAX  <special>

DESCRIPTION
        Used after condition checks to make FPL execute certain parts of the
        program if the previous check did not evaluate true.

        It always belongs to the last `if'/`while' in this block.

EXAMPLES
        It can be used in simple one time checks like:

          if(a!=2)
            break;
          else
            output("hello");  /* only executed if variable a equals 2 */


                                 - Page 31 -
59.    else

        and even if a while loop never is executed:

          while(a--)
            output(a);
          else
            output("hello"); // only executed if the while condition never
                             // was true.

        Take a look at the two examples below and note the difference!

        1. If both "a" and "b" are true, then invoke "build_new_things". if
           "a" is false, invoke "crash_mostofit":

          if(a) { // braces are required if we want the `else' to affect this
            if(b)
              build_new_things();
          } else
            crash_mostofit();

        2. If "a" and "b" are true, then invoke "build_new_things". If "a" is
           true and "b" is false, invoke "crash_mostofit":

          if(a) // without braces, the else suddenly affects the other if!
            if(b)
              build_new_things();
            else
              crash_mostofit();

60.    exit

SYNTAX  exit( return_code );

DESCRIPTION
        Stop execution of the current FPL routine.

INPUTS  int/string return_code  - Return code to return to the calling
                                  process.

        See the documentation for the software you're controlling for the
        exact meaning of these return codes. The return code can be excluded
        as well as the parenthesis can when returning a value.

RETURNS
        A result code to the invoking environment.

SEE ALSO
         return

61.    export

SYNTAX  export [ global declaration ];

DESCRIPTION
        Make the following global symbol available to all programs.

EXAMPLES
        The following statements make the function "foobar" and the string
        variable "String" accessiable to all other FPL programs that will
        succeed this program:

          export string String;
          export int foobar(int);
          /* the actual function foobar must reside in the same source file */

62.    for

SYNTAX  for ([expression1] ; [expression2] ; [expression3]) statement;

                                 - Page 32 -
62.    for


DESCRIPTION
        Expression1
          is evaluated only before the statement is processed for the first
          time. You can use this expression to initialize a variable. If you
          do not want to evaluate an expression prior to the first iteration
          of the statement, you can omit this expression.

        Expression2
          is evaluated before each iteration of the statement. The expression
          must evaluate to a scalar type. If it evaluates to 0 (zero), the
          statement is not processed and control moves to the next statement
          following the for statement. If expression2 does not evaluate to 0,
          the statement is processed. If you omit expression2, it is as if
          the expression had been replaced by a nonzero constant and the for
          statement is not terminated by failure of this condition.

        Expression3
          is evaluated after each iteration of the statement. You can use
          this expression to increase, decrease, or reinitialize a variable.
          If you do not want to evaluate an expression after each iteration
          of the statement, you can omit this expression.

        A break or return statement can cause the processing of a for
        statement to end, even when the second expression does not evaluate
        to 0 (zero). If you omit expression2, you must use a break or a
        return statement to stop the the for statement from running.

EXAMPLES

        The following for statement prints the value of count 20 times. The
        for statement initially sets the value of count to 1. After each
        iteration of the statement, count is incremented.

          for (count = 1; count <= 20; count++) {
            output("count =", count);
          }

        The following sequence of statements accomplishes the same task. Note
        the use of the while statement instead of the for statement.

          count = 1;
          while (count <= 20) {
            output("count = ", count);
            count++;
          }

        The following for statement does not contain an initialization
        expression.

          for (; index > 10; index--) {
            list= var1 + index;
            output("list = ", list, "\n");
          }

        The following for statement continues running until input receives
        the letter e:

          for (;;) {
            input("Gimme an e!", letter);
            if (!strcmp(letter, "\n"))
              continue;
            else if (!strcmp(letter, "e"))
              break;
            output("You entered the letter", letter);
          }


                                 - Page 33 -
62.    for

        The following for statement contains multipart initializations and
        increments.  The comma operator makes this construction possible.

          for (i = 0, j = 50; i < 10; i++, j += 50) {
            output("i = ", i, " and j = ", j);
          }

        The following example shows a nested for statement. The outer
        statement is run as long as the value of row is less than 5. Each
        time the outer for statement is processed, the inner for statement
        sets the initial value of column to zero and the statement of the
        inner for statement is run three times. The inner statement is run
        as long as the value of column is less than 3.

          for (row = 0; row < 5; row++) {
            for (column = 0; column < 3; column++)
              output("column * row =", row * column, "\n");

        A never-ending loop using `for':

          for(;;)
            perform_until_death();

SEE      break , continue, do, while

63.    if

SYNTAX  if ( expression ) statement; [ else  statement;  ]

DESCRIPTION
        An if statement allows you to conditionally process a statement if
        the specified test expression evaluates to a nonzero value. You can
        optionally specify an else clause on the if statement. If the test
        expression evaluates to 0 (zero), and an else clause exists, the
        statement in the else clause is run. If the test expression evaluates
        to a nonzero value, the statement following the expression runs and
        the else clause is ignored.

        When if statements are nested and else clauses are present, a given
        else is associated with the closest preceding if statement within the
        same block.

EXAMPLES
        The following example causes grade to receive the value A if the
        value of score is greater than or equal to 90.

          if (score >= 90)
            grade = A;

        The following example displays number is positive if the value of
        number is greater or equal to 0 (zero). Otherwise, the example
        displays number is negative.

          if (number >= 0)
            output("number is positive\n");
          else
            output("number is negative\n");


        The following example shows a nested if statement:

          if (paygrade == 7)
            if (level >= 0 && level <= 8)
              salary *= 2;
            else
              salary *= 3;
          else

                                 - Page 34 -
63.    if

             salary *= 4;


        The following example shows an if statement that does not have an
        else clause.

          if (gallons > 0) {
            if (miles > gallons)
              mpg = miles/gallons;
          } else
            mpg = 0;


        The following example shows an if statement nested within an else
        clause. This example tests multiple conditions.  The tests are made
        in order of their appearance. If one test evaluates to a nonzero
        value, an action statement runs and the entire if statement ends.

          if (value > 0)
             increase++;
          else if (value == 0)
             breaeven++;
          else
             ++decrease;

64.    int

SYNTAX  int name [= expression];

          or

        long name [= expression];

DESCRIPTION
        Declare an integer (signed 32-bit) variable and assign a value to it.
        Read more about it the chapter discussing variables. Not assigned
        variables equals zero (0) after declaration.

        ANSI C specifies that `long' should be a 32-bit number and `int' is
        more vague. The MC680x0 processor series has - as all decent
        processors have - 32-bit integers, which make them the exact same
        data type. FPL is mostly run on such processors making this
        equivalence natural.

INPUTS  string name             - The variable name.
        int/long expression     - Initial expression.

SEE      string ,  char   ,  short

65.    resize

SYNTAX  resize name [ new_size ] ;

DESCRIPTION
        A common problem when using arrays is that you don't know the size of
        it already from the start. This keyword brings a solution to that
        problem. This one resizes the named array to the new size you specify
        inside the square brackets. Notice that it's also possible to reduce
        the size, so be careful not to destroy data you like to reuse.

        WARNING: Using multi dimensional arrays and `resize' is a dangerous
        combination. E.g when changing an array from "[4][5]" to "[5][5]",
        the old values will not any longer be readable in their old array
        members. A resize of this kind makes the data move around a bit
        depending on the internal data array storage. DO NOT USE `resize' IN
        MULTI DIMENSIONAL ARRAYS IF YOU WANT THE DATA TO STAY INTACT!


                                 - Page 35 -
65.    resize

INPUTS
        name            - The name of the array you'd like to resize.
        new_size        - The new size of the array.

EXAMPLES
        To make a list of all the names the user enters, you need an array as
        big as the user pleases. But declaring an enormous size from the
        start really isn't to recommend. This example shows one way to solve
        such a problem:

          int roof=10, num;
          string names[roof];
          do {
            if(num==roof)
              resize names[roof+=10];
            names[num]=input("Insert name number " num ":");
          } while(names[num++]!="");


        Multi dimensional arrays looses their proper values when resizing, do
        copy the array to preserve to contents:

          int a[DIM1][DIM2];       // This is the old array construction
          {
            /* This could with benefit be written into a function to be
               called from several instances */

            int n1, n2;              // counter variables
            int b[NEWDIM1][NEWDIM2]; // The temporary new array outfit!

            for(n1=0; n1<DIM1 && n1<NEWDIM1; n1++)   // temporary store all
              for(n2=0; n2<DIM2 && n2<NEWDIM2; n2++) // vital data in array b
                b[n1][n2]=a[n1][n2];

            resize a[NEWDIM1][NEWDIM2]; // resize a

            for(n1=0; n1<NEWDIM1; n1++)   // restore all data to array a
              for(n2=0; n2<NEWDIM2; n2++)
                a[n1][n2]=b[n1][n2];
          }

66.    return

SYNTAX  return [ return_code ];

DESCRIPTION
        A return statement ends the execution of the current function and
        returns a return code and control to the caller of it. The return
        code is written exact as in C, within parentheses or not. It can
        also be totally excluded.

EXAMPLES
        We use a function to print the result of the formula, but only if
        the result is even:

          int n;
          int print(int);
          for(n=0; n<10; n++)
            n+=printf(n*n);
          exit;

          int print(int a)
          {
            if(!(a&1))
              output(a);
             return(a&2);  /* Get back to the for loop */
          }

                                 - Page 36 -
66.    return


SEE      exit ,  break

67.    short

SYNTAX  short name [= expression];

DESCRIPTION
        Declares a short (signed 16-bit) variable (and assigns a value to
        it). Read more about it the chapter discussing variables. Not
        assigned variables equal zero (0) after declaration.

INPUTS  string name        - The variable name.
        short expression   - Initial expression.

SEE     int , char, string

68.    string

* Strings are always written enclosed within quotation marks (").

* To read the ASCII value of a single character within a string, use
  square brackets in the form: name[index] where name is the name of
  the string variable (could of course also be an array member) and   index is
the column you want to check out. Index below zero or above
  the length of the source string will result in error. The following
  example outputs all ASCII codes in a string:

     string  str = "hello world";
     int  ascii, n;
     while ( ascii = str[n++] ) {
       output ( ascii "n" );
    }

  This example will output all ASCII values in column 2 in the strings
  in the array:

     string  str[3] = {"hello", "world", "string"};
     int  n;
     for ( n = 0; n < 3; n++ ) {
       output ( str[n][2] "n" )
    }

  Reading beyond the end of a string simply returns a zero, while
  reading a negative column will result in an error.

* Strings not enclosed within quotes are assumed to be variable names.

  Note the difference between:

    output("Hello");

  and

    output(Hello);

  (Example 1 outputs the actual string "Hello", while example 2 outputs
  the contents of the variable *named* "Hello".)

* Append strings to a string variable by using the '+=' operator. Ex:

    string a="Hello ";
    a+="world";
    output(a);

  Outputs the string "Hello world" on the screen.


                                 - Page 37 -
68.    string

    string a = "Hello ";
    string b ="world";
    output( a + b );

* Special characters within strings should be symbolized with backslash
  and a character just as in the good old C standard:
  a    - Alert (bell)
  b    - Backspace
  f    - Form feed (new page)
  n    - New-line
  r    - Carriage return
  t    - Horizontal tab
  v    - Vertical tab
  '    - Single quotation mark
  "    - Double quotation mark
  ?    - Question mark
  \    - Backslash
  xhh  - hex number, where "hh" is a two digit hexadecimal value.
  nnn  - octal number, where "nnn" is a three digit octal value.

See also the function reference for string handling functions such as
 strcmp(), strncmp(), substr(), eval() and more.

69.    typedef

SYNTAX  typedef <declarator> <symbol>;

DESCRIPTION
        `typedef' allows you to define your own identifiers that can be used
        in place of FPL type specifiers such as int, string and char. The
        data types you define using `typedef' are not new data types; they
        are synonyms for the primary data types used by FPL.

EXAMPLES
        This example creates a synonym for int and then use that to declare
        three integral variables:

                typedef int LENGTH;     /* new declarator named `LENGTH' */
                LENGTH length, width, height;

70.    switch

SYNTAX  switch ( expression ) { [case expression:] [default:expression] }

DESCRIPTION
        A switch statement lets you define actions to different results of
        the switch expression.

        The result of the expression written within the parentheses following
        the switch keyword is matched against the expressions following the
        ' case ' keywords within the braces. If no match is found the action
        specified after ' default ' will be run. If no 'default' is defined
        either, nothing will happen.

        The switch expression may be either a string or numerical expression.
        The expressions in the following case statements have to be of the
        same expression type as the initial one, or FPL will report error.

        Multiple cases may be specified with the same expression, but only
        the first one that match the switch expression will be run.

        A case statement is aborted by a  break  statement or the brace
        ending the switch statement.

NOTE
        Unlike C, FPL handles dynamic expressions in case-statements very
        well!

                                 - Page 38 -
70.    switch


        The case statements will be parsed/scanned from the top to bottom.
        For speed reasons, you should put the case-statements that occur
        most likely at the top and the least likely case-statements at
        the bottom.

EXAMPLES

        In the following program the result from the equation 'x+5' is
        controlling what text to assign to the 'output' variable:

          int check = x + 5;
          string output;
          switch( check ) {
            case 5:     /* notice the colon that follows the expression */
              output = "x was zero";
              break;    /* escape from switch! */

            case 4:
              break;    /* do nothing */

            case 7:
              /* fall through! */

            case 8:
              output = "x was two or three";
              break;

            default:
              output = "x was not from -1 to 3";
          }   /* breaks out of 'default' */

        In the following program, the content of the variable 'username' is
        controlling which function to invoke:

          string username = getname();  /* get user name */
          switch(username) {
            case "superuser":
              GetSuperUser();
              break;

            case "normal":
              GetNormalUser();
              break;

            case "unworthy":
              GetUnworthyUser();
              break;
          }

71.    while

SYNTAX  while ( expression )  statement ; [  else  statement; ]

DESCRIPTION
        A while statement enables you to repeatedly run the body of a loop
        until the controlling expression is no longer met or evaluates to 0
        (zero.)

        The expression is evaluated to determine whether or not the body of
        the loop should be run. If the expression evaluates to 0 (zero), the
        body of the loop never runs. If not, the body is processed. After the
        body has run, control passes back to the expression. Further
        processing depends on the value of the condition.

        When coding in 'C', I've always missed the "while else" function. FPL
        includes that feature! If the test expression evaluates to false

                                 - Page 39 -
71.    while

        (zero) the FIRST TIME it's evaluated, and an "else" clause exists,
        the statement in the "else" clause is run. If the test expression
        evaluates to a nonzero value, the statement following the expression
        runs and the "else" clause is ignored.

        A break or return statement can cause the processing of a while
        statement to end, even when the condition does not evaluate to 0
        (zero).

        NOTE: The else clause is *NOT* a loop. "break" is not a valid move to
        break out of such.

EXAMPLES

        In the following program, item triples each time the value of the
        expression index++ is less than MAX_INDEX. When index++ evaluates to
        MAX_INDEX, the while statement ends.

          while (index < MAX_INDEX) {
            item *= 3;
            output("item = ", item, "\n");
            index++;
          }

        The following program first checks if a<0 and if it is, increases a
        with 100 until it isn't any longer less than zero. If not, it'll
        output a message saying so.

          while(a<0)
            a+=100;
          else
            output("a was never below 0\n");


SEE      break ,  return , continue

72.    Functions

  These are the internal functions supplied from the start by FPL:

  Function          Argument(s)     Short Description
  --------          -----------     -----------------

   abs              int           Absolute value of integer operand.
   atoi             str           Convert a string to an integer.
   eval             str           Calculate a string.
   interpret        str           Interpret string as program.
   itoa             int           Convert an integer to string.
   itoc             int           Convert an integer to ASCII.
   joinstr          str, ...      Joins strings!
   ltostr           n1, n2        Convert an integer to string.
   sprintf                        Formatted print to a string.
   strcmp           str1, str2    Compare two strings.
   stricmp          str1, str2    Compare two strings. CI(*)
   strlen           str]          String length.
   strncmp          str1, str2, n Compare two strings a certain length.
   strnicmp         str1, str2, n Compare two strings a certain length. CI(*)
   strstr           str1, str2    Find substring str1 in string str2.
   stristr          str1, str2    Find substring str1 in string str2. CI(*)
   strtol           str, base     Convert string to integer.
   substr           s1, col, len  Get part of string.

 [Amiga only:]

   openlib          lib, ver        Open funclib.
   closelib         lib             Close funclib.


                                 - Page 40 -
72.    Functions

(*) = Case insensitive. It doesn't make any difference to 'A' or 'a'.
      It does only apply to ASCII characters; that is only a-z and A-Z.

73.    abs

SYNTAX  int abs( Int );

DESCRIPTION
        Returns the absolute value of the input integer.

INPUTS  int Int;

RETURNS see description.

74.    atoi

SYNTAX  int atoi( String );

DESCRIPTION
        The atoi keyword returns an integer whose value is represented by the
        character string pointed to by the String parameter. atoi scans the
        string up to the first character that is inconsistent. Leading
        white-space characters are ignored, and an optional sign may precede
        the digits.

INPUTS  string String;

RETURNS
        Upon successful completion, atoi returns the converted value. If no
        conversion could be performed, 0 (zero) is returned. If the correct
        value is outside the range of representable values, maximum or
        minimum value is returned according to the sign of the value.

SEE
        strtol(), itoa()

75.    closelib

SYNTAX  int closelib( Name );

DESCRIPTION
         Closes a specified  funclib . Funclibs are third
        party programs that add functions to the FPL session. The funclibs
        should be stored in FPLLIBS:.

         A closelib() concludes access to the functions of the specified
        funclib. Each call to  openlib()  should have a matching call to
        closelib().

         For information regarding specified funclibs, refer to the manual of
        the particular funclib.

INPUTS
        string Name     - The name of the funclib.

RETURNS
        It return 0 on success. Otherwise see 'openlib' for closer
        description.

SEE      openlib  and the  funclibs  section.

76.    eval

SYNTAX  int eval( String );

DESCRIPTION
        The mathematical expression in String is evaluated and returned.

                                 - Page 41 -
76.    eval

        eval handles all variables declared before this point of the
        execution.
        An error in the expression will unfortunately return 0 which will
        look like the result of the expression.

INPUTS  string String   - A string including a valid numerical expression.

RETURNS
        The result of the mathematical expression in String or 0 if there was
        any error in the expression.

77.    interpret

SYNTAX  int interpret( String );                        (V3)

DESCRIPTION
        Interprets the argument as if it is a continuation of the program.
        The argument must be a 100% correct FPL program statement. All
        variables and functions usable in the program at this point will be
        usable in the argument-statement too.

        Any error in this function will get reported at the position right
        after the function call.

INPUTS  string String   - FPL statement

RETURNS
        At this moment: always zero. But do not depend upon that since it
        might get changed in the future.

EXAMPLE
        This example calls a function via the interpret() function:

                int foobar(int);
                interpret("foobar(2);");
                exit;

                int foobar(int b)
                {
                  output(b);
                }

        We can create a function that accepts a function name as parameter
        and then is able to call that named function:

                int foobar(int);
                int foo(int);
                int bar(int);
                int call(string, int);

                call("foobar", 1);
                call("foo", 2);
                call("bar", 3);
                exit;

                int call(string command, int parameter)
                {
                  int ret;      /* declare return code variable */
                  string statement=joinstr("ret=", command, "(",
                                           ltostr(parameter), ");");

                  output(statement);    /* output the statement */
                  interpret(statement); /* interpret it */
                  /*
                   * At this point `ret' has got the return code
                   * of the called function.
                   */

                                 - Page 42 -
77.    interpret

                  return(ret);
                }

                /*
                 * Here should the definitions of the functions
                 * "foobar", "foo" and "bar" be programmed.
                 */

SEE      eval

78.    itoa

SYNTAX  string itoa( Integer );

DESCRIPTION
        The itoa function converts the integer given as argument to a string
        and returns it. The convertion will use base 10, which creates a
        decimal number.

INPUTS
        int Integer     - Number to be converted.

RETURNS
          Upon successful completion, the function returns the converted
        string. If no conversion could be performed, the returned string is
        zero-length.

EXAMPLES
        Convert the number the variable 'num' holds, to a string:

          string result= itoa(num);

SEE     ltostr(), atoi()

79.    itoc

SYNTAX  string itoc( Integer );

DESCRIPTION
          The itoc function returns the character with the ASCII code
        given as argument. Any argument number higher than 255 will be ANDed
        with 255 internally.

INPUTS
        int Integer     - ASCII code of the desired character.

RETURNS
          Upon successful completion, the function returns the character
        as a string.

EXAMPLES
        To get the character with ASCII number 137:

          string result= itoc( 137 );

SEE      itoa

80.    joinstr

SYNTAX  string joinstr( String, ... );

DESCRIPTION
         This function lets you specify any amount of strings, and returns
        them all as one concatenated single string.

INPUT   string String   - Strings to be merged.


                                 - Page 43 -
80.    joinstr

RETURNS
        A string holding all joined strings.

EXAMPLES
        Merge three strings into one:

          string a="one ", c="two ", b="three", d;
          d=joinstr(a, b, c); /* 'd' now holds "one two three" */

81.    ltostr

SYNTAX  string ltostr( Integer, Base );

DESCRIPTION
          The ltostr subroutine returns a string which is the first parameter
        converted using the second parameter as base.

          If the Base parameter is positive and not greater than 36, then it
        is used as the base for conversion.

INPUTS
        int Integer     - Number to be converted.
        int Base        - Specifies the base to use for the conversion.

RETURNS
          Upon successful completion, the ltostr subroutine returns the
        converted string. If no conversion could be performed, the returned
        string is zero-length.

EXAMPLES
        Convert the number 1993 to hexadecimal:

          string result= ltostr(1993, 16);

SEE     strtol(), itoa()

82.    openlib

SYNTAX  int openlib( Name, Version );

DESCRIPTION
         Opens a specified  funclib . Funclibs are third
        party programs that add functions to the FPL session. The funclibs
        should be stored in FPLLIBS:.

         An openlib() gains access to the functions of the specified funclib.
        After finished using the functions of that funclib, the session
should
        be concluded with a call to  closelib() . Each
        call to openlib() should have a matching call to closelib().

         For information regarding specified funclibs, refer to the manual of
        the particular funclib.

INPUTS
        string Name     - The name of the funclib.
        int Version     - The lowest acceptable version of the funclib.

RETURNS
        It return 0 on success. Otherwise a non-zero number where the numbers
        have the following meaning:
        1 - funclib parameter error
        2 - internal funclib error
        3 - failed getting a system resource
        4 - out of memory error
        5 - failed loading the funclib (occurs if you open a non-existant
            funclib).

                                 - Page 44 -
82.    openlib

        6 - the requested version didn't exist
        More error codes are likely to be added within short.

SEE      closelib  and the  funclibs  section.

83.    sprintf

SYNTAX  string sprintf (format, arg1, arg2, ...);

DESCRIPTION

        This function produces a string of ASCII characters.

        The format argument holds a string that contains ordinary
        characters and conversion specifications that indicate how you
        want the arguments arg1, arg2, and so on to be printed. The
        ordinary characters are copied to the result string, but the
        conversion specifications are replaced with the correctly formatted
        values of the arguments arg1, arg2, and so on. The first conversion
        specification is replaced with the formatted value of arg1, the
        second specification is replaced with the value of arg2, and so
        on. In some cases, as described below, a conversion specification
        may process more than one argument.

        Each conversion specification must begin with a percent character
        (%). To place an ordinary percent into the output stream, precede
        it with another percent in the fmt string. That is, %% will send
        a single percent character to the output stream. A specification
        has the following format:

            %[arg][flags][width][.precision][size]type

        The brackets ([]) indicate optional fields.  Each field is defined
        as follows:

            arg
                FPL supports the argument number selection style $<arg>.
                When an argument number has been given, that specified
                argument will be used instead of the next one in turn.
                I.e "%$2d" will produce a formatted integer found as the
                second argument. You should *not* mix specified arugment
                numbers with %-codes with unspecified arugment numbers.

            flags
                controls output justification and the printing of signs,
                blanks, decimal places, and hexadecimal prefixes.

                If any flag characters are used, they must appear after
                the percent.  Valid flags are as follows:

                - (minus)
                    causes the result to be left-justified within the
                    field specified by width or within the default width.

                + (plus)
                    causes a plus or minus sign to be placed before the
                    result.  This flag is used in conjunction with the
                    various numeric conversion types.  If it is absent,
                    the sign character is generated only for a negative
                    number.

                blank
                    causes a leading blank for a positive number and a
                    minus sign for a negative number.  This flag is
                    similar to the plus.  If both the plus and the blank
                    flags are present, the plus takes precedence.


                                 - Page 45 -
83.    sprintf

                # (pound)
                    causes special formatting.  With the o, x, and X
                    types, the pound flag prefixes any nonzero output with
                    0, 0x, or 0X, respectively.  With the f, e, and E
                    conversion types, the pound flag forces the result to
                    contain a decimal point.  With the g and G types, the
                    pound flag forces the result to contain a decimal
                    point and retain trailing zeroes.

                0 (zero)
                    pads the field width with leading zeros instead of
                    spaces for the d, i, o, u, x, X, e, E, f, g, and G
                    conversion types.  If the minus flag is also used, the
                    zero flag is ignored.  If a precision is specified,
                    the zero flag is ignored for conversion types d, i, o,
                    u, x, and X.  Behavior of the zero flag is undefined
                    for the remaining conversion types.

            width
                specifies the field width, which is the minimum number of
                characters to be generated for this format item.

                The width is a nonnegative number that specifies the
                minimum field width.  If fewer characters are generated by
                the conversion operation, the result is padded on the left
                or right (depending on the minus flag described above).  A
                blank is used as the padding character unless width begins
                with a zero.  In that case, zero padding is performed.  If
                the minus flag appears, padding is performed with blanks.
                width specifies the minimum field width, and it will not
                cause lengthy output to be truncated.  Use the precision
                specifier for that purpose.

                If you do not want to specify the field width as a
                constant in the format string, you can code it as an
                asterisk (*), with or without a leading zero.  The
                asterisk indicates that the width value is an integer in
                the argument list. See the examples for more information
                on this technique. If the asterisk is followed by a $ sign
                and a digit 1-9, you can specify which argument that holds
                the width.

            precision
                specifies the field precision, which is the required
                precision of numeric conversions or the maximum number of
                characters to be copied from a string, depending on the
                type field.

                The meaning of the precision item depends on the field
                type, as follows:

                 Type                  Meaning
                 ----                  -------
                  c                    The precision item is ignored.
                  b, d, i, o, u, x, X  The precision is the minimum number
                                       of digits to appear.  If fewer
                                       digits are generated, leading
                                       zeroes are supplied.
                  s                    The precision is the maximum number
                                       of characters to be copied from the
                                       string.

                As with the width item, you can use an asterisk for the
                precision to indicate that the value should be picked up
                from the next argument.

            size

                                 - Page 46 -
83.    sprintf

                Not used by FPL, though all the ANSI C modifiers are still
                read and ignored for compatibility.
                (Can be either L for long double, l for large size, or h
                for small size.)

            type
                specifies the type of argument conversion to be done.
                Valid conversion types are as follows:

                    b
                        specifies binary-integer conversion. The
                        associated argument is taken as an unsigned
                        integer, and it is converted to a string of binary
                        digits.  This conversion type is an extension to
                        the ANSI standard.
                    c
                        specifies single-character conversion. The
                        associated argument must be an integer.  The
                        single character in the right-most byte of the
                        integer is copied to the output.
                    d
                        specifies decimal-integer conversion. The
                        associated argument must be an integer, and the
                        result is a string of digits preceded by a sign.
                        If the plus and blank flags are absent, the sign
                        is produced only for a negative integer.
                    i
                        specifies decimal-integer conversion. The
                        associated argument must be an integer, and the
                        result is a string of digits preceded by a sign.
                        If the plus and blank flags are absent, the sign
                        is produced only for a negative integer.
                    n
                        specifies the argument will be a pointer to an
                        integer into which is written the number of
                        characters written so far by this call to the
                        sprintf function.
                    o
                        specifies octal-integer conversion. The
                        associated argument is taken as an unsigned
                        integer, and it is converted to a string of octal
                        digits.
                    p
                        specifies pointer conversion.  The associated
                        argument is taken as a data pointer, and it is
                        converted to hexadecimal representation.  Under
                        AmigaDOS, the pointer is printed as 8 hexadecimal
                        digits, with leading zeroes if necessary.
                    P
                        specifies pointer conversion. This is the same as
                        the p format, except that uppercase letters are
                        used as hexadecimal digits. This conversion type
                        is an extension to the ANSI standard.
                    s
                        specifies string conversion. The associated argument
                        must be a string!
                    u
                        specifies unsigned decimal integer conversion.
                        The associated argument is taken as an unsigned
                        integer, and it is converted to a string of
                        decimal digits.
                    x
                        specifies hexadecimal-integer conversion.  The
                        associated argument is taken as an unsigned
                        integer, and it is converted to a string of
                        hexadecimal digits with lowercase letters.
                    X

                                 - Page 47 -
83.    sprintf

                        specifies hexadecimal-integer conversion.  This is
                        the same as the x format, except that uppercase
                        letters are used as hexadecimal digits.

RETURNS

        This function returns the formatted string.

EXAMPLE

        /* This example prints a message indicating whether */
        /* the function argument is positive or negative.   */
        /* In the second sprintf, the width and precision   */
        /* are 15 and 8, respectively.                      */
        string pneg(int value)
        {
            string sign;

            if (value < 0) {
              sign = "negative";
            }
            else {
              sign = "not negative";
            }
            return sprintf("The number %d is %s.n",value,sign);
        }

        Output(pneg(37));
        Output(pneg(-18));

        /* This example outputs 12 and 8 in reversed order by using the
           specified argument number syntax: */

        Output( sprintf( " %$2d %$1d ", 12, 8 ) );

84.    strcmp

SYNTAX  int strcmp ( String1, String2 );

        int stricmp ( String1, String2 );

DESCRIPTION
        strcmp lexicographically compares the string in the String1
        parameter to the string in the String2 parameter. stricmp() does
        the same but does a case insensitive compare, which makes uppercase
        letters equal their lowercase correspondance.

        Case insensitive means that the strings "HELLO" and "hello" are
        treated as identical.

INPUTS  string String1, String2;

RETURNS
        strcmp and stricmp return values that are:

        Less than 0 (zero) if String1 is less than String2
        Equal to 0 (zero) if String1 is equal to String2
        Greater than 0 (zero) if String1 is greater than String2.

SEE     strncmp and strnicmp

85.    strlen

SYNTAX  int strlen( String );

DESCRIPTION
        Returns the length of the string String.

                                 - Page 48 -
85.    strlen


INPUTS  string  String;

RETURNS
        The length of the string String.

86.    strncmp

SYNTAX  int strncmp ( String1, String2, Num );

        int strnicmp ( String1, String2, Num );

DESCRIPTION
        The strncmp and strnicmp subroutines make the same comparisons as
        strcmp and stricmp, but they compare at most 'Num' characters.

INPUTS  string String1, String2;
        int Number      - Maximum number of characters to compare.

RETURNS
        they return values that are:

        Less than 0 (zero) if String1 is less than String2
        Equal to 0 (zero) if String1 is equal to String2
        Greater than 0 (zero) if String1 is greater than String2.

EXAMPLES
        Compare the string variable Str1 and check if it matches Str2, but
        check no more than 12 characters:

          if(!strncmp(Str1, Str2, 12))
            output("MATCH!");

        This example returns zero (0) in result.

          result = strncmp("realization", "really", 4);

        This example returns a value less than zero in result.

          result = strncmp("world", "worldgames", 100);


SEE     strcmp() and stricmp()

87.    strstr

SYNTAX  int strstr( String1, String2, Column );

        int stristr ( String1, String2, Column );

DESCRIPTION
        The strstr and stristr functions find occurrences of String2 in
        String1.

        The 'Column' parameter can be set optionally. It specifies the start
        searching column!

        strstr() requires the substring to match exactly, while the stristr()
        performs a case insentive search. Case insensitive means that the
        strings "HELLO" and "hello" are treated as identical.

INPUTS
        string String1  - The string to search within.

        string String2  - The substring.

        int Column      - Start search column.

                                 - Page 49 -
87.    strstr


RETURNS
        They return in which column they found String2 or -1 if the string
        was not found. If String2 is a 0 (zero) length string, the functions
        return 0.

SEE     strncmp and strnicmp, strcmp and stricmp

88.    strtol

SYNTAX  int strtol( String, Base );

DESCRIPTION
          The strtol subroutine returns an integer whose value is represented
        by the character string pointed to by the String parameter. The
        strtol subroutine scans the string up to the first character that is
        inconsistent with the Base parameter. Leading white-space characters
        are ignored, and an optional sign may precede the digits.

          If the Base parameter is positive and not greater than 36, then it
        is used as the base for conversion. After an optional leading sign,
        leading zeros are ignored. "0x" or "0X" is ignored if Base is 16
        (sixteen).

          If the Base parameter is 0 (zero), the string determines the base.
        Thus, after an optional leading sign, a leading 0 (zero) indicates
        octal conversion, a leading "0x" or "0X" indicates hexadecimal
        conversion and a leading "0b" or "0B" indicates a binary conversion.
        The default is to use decimal conversion.

INPUTS  string String   - Character string to be converted.
        int Base        - Specifies the base to use for the conversion.

RETURNS
          Upon successful completion, the strtol subroutine return the
        converted value. If no conversion could be performed, 0 (zero) is
        returned. If the correct value is outside the range of representable
        values, maximum or minimum value is returned according to the sign of
        the value.

EXAMPLES
        Convert the string holding the hexadecimal "0xdeadbeef" to decimal:

          string String = "0xdeadbeef"
          int num = strtol(String, 16);

SEE      ltostr

89.    substr

SYNTAX  string substr( Source, Column, Length );

DESCRIPTION
        The substr function returns a substring to a destination string
        variable. Giving a length of -1 will make substr get the rest
        of the string from the column specified.

        - If the substring is told to keep on beyond the end of the Source,
          the substring will end where the Source string does.

        - If the column parameter is below zero or larger than the length of
          the source string, a zero length string is returned.

        - The first column of the source is column 0 (zero).

INPUTS
        string Source   - The source string from which the substring

                                 - Page 50 -
89.    substr

                          will be copied from. */
        int Column      - Start column of the substring.
        int Length      - The Length of the substring.

RETURNS
        The substring!

EXAMPLES
        Extract a substring of 3 characters from column 4 of the source
        string:

          string Dest;
          Dest=substr("One Two Three", 4, 3);

        Get the right part of a line split by the character "|":

          string Line="Names     |Addresses", Dest;
          int pos;
          pos=strstr(Line, "|");
          if(pos<0)                     /* if we can't find a "|" */
            exit;

          pos++;                        /* We don't want to include the "|"
                                           Character in our substring! */
          Dest=substr(Line,             /* The source string */
                      pos,              /* where from */
                      -1);               /* To the end of the string. */

        It's OK to try getting more than you will get. This example get the
        rest of the line too, but maximum 10000 characters...:

          Dest=substr(Line, pos, 10000);

SEE     strstr() and stristr()

90.    Examples

1. Ask the user for his age and output the number of days old he is:

  int a;                            /* Create an integer called "a"  */
  a=num_input("Age in years:");     /* Get age of user in variable a */
  output("Makes " a*365 " days!\n");/* Output proper text            */


2. Ask the user for his name and output it a hundred times with spaces
   between:

  string name;                          /* Create a string variable */
  name=str_input("What's your name?");  /* Input name               */
  int i;                                /* Create an integer        */
  for (i=0; i<100; i++)                 /* Count 100 times          */
    output(name " ");                   /* Output the name          */


3. Replace all form feed characters with the proper number of newlines
   to suit the page length given by the user (for guys using
   printers which by some reason don't handle form feeds):

  int len, i, page;                     // Create a number of ints
  len=num_input("Page length?");        // Get page length
  while(search_for("\f", "S")) {        // Search for form feed
    page=len-line()%len;                // Calc number of newlines
    for(i=0, i<page, i++)               // Count to number above
      output("\n");                     // Output a newline
  }                                     // End of while
  status("Done!");                      // Text in status line.


                                 - Page 51 -
90.    Examples


4. Make a nice little table with temperatures in Celsius and
   Fahrenheit. Count from 0 to 100 Celsius with ten degrees steps:

  int c, f;                     /* Declare two variables             */
  while(c<=100) {               /* while c less than or equal to 100 */
    output(c" degrees Celsius = ");/* output Celsius                 */
    f=c*18/10+32;               /* The formula. Made to work
                                   without floating points           */
    output(f" degrees Fahrenheit! \n"); /* output Fahrenheit result  */
    c+=10;                      /* Add ten to c.                     */
  }                             /* loop                              */

5. Create a routine that make a division with an innumerable number of
   decimals:

  int a, b, n;                  /* Declare all variables needed     */
  a=355;                        /* Set the operands of the division */
  b=14;
  output(a " / " b " = ");      /* View the evaluation to the user  */
  output(a/b);                  /* Calculate...                     */
  if(a%b) {                     /* If there remains anything...     */
    output(".");                /* Display a dot.                   */
    for(n=0;n<100;n++) {        /* Only 100 decimals this time!     */
      a=a%b*10;                 /* Evaluate next left operator      */
      output(a/b);              /* View the next figure             */
    }
  }
  output("\n");                 /* Make an extra newline            */


6. Perform the same task as above. This is an example program showing
   some simple moves to make the code run faster:

  int a=355, b=14, n;
  string s=a" / "b" = "(a/b);
  if(a%b)
    for(s+=".";n++<100;)
      s+=((a=a%b*10)/b);
  output(s"\n");

7. Try out the recursive possibilities of FPL:

  int b;
  int label(int &);
  label(b);
  output(b"\n");
  exit;

  int label(int &b)
  {
    if(++b<5) {
      while(1) {{{{{{label(b);break;}}}}}}
    }
    return;
  }

91.    Error messages

DIVISION BY ZERO
  Division by zero is not a permitted mathematical move (note that this may
  also appear with the remainder operator "%").
  See  division  or  remainder .

FILE
  Something about the specified file is wrong. Check the file name again.


                                 - Page 52 -
91.    Error messages

IDENTIFIER NOT FOUND
  The variable or function is not found!

IDENTIFIER ALREADY USED
  This name is already used by an identifier. You cannot use it too!

ILLEGAL ARRAY
  You cannot create an array with less than one element, access elements with
  higher number than you declared it to or access negative elements. When
  using the resize keyword the variable name must already be an array.
  See  variables  or  resize .

ILLEGAL ASSIGN
  FPL does not support that type of  compound assignment .

ILLEGAL BREAK
   Break  can ONLY be used within some kind of loop ( while ,  for  or  do )
  or  switch , and this wasn't such a  statement .

ILLEGAL CASE
  The 'case' keyword can only be used within a switch() statement!

ILLEGAL CONDITION OPERATOR
  Conditional operators should be used like a ? b : c. If any of the ? or :
  characters are missing, this might become the error message!

ILLEGAL CONTINUE
   Continue  can ONLY be used within some kind of loop ( while ,  for  or
   do ), and this wasn't such a  statement .

ILLEGAL DECLARATION
  The  declaration  was not placed in the beginning of a block,
  or a function isn't declared the way it was prototyped.

ILLEGAL DEFAULT
  The 'default' keyword can only be used within a switch() statement!

ILLEGAL PROTOTYPE
  Something in the just parsed function prototype was not using
  correct syntax and/or keywords.

ILLEGAL REFERENCE
  A variable reference was used the wrong way!

ILLEGAL RESIZE
  Resizing of an array did not follow correct syntax!

ILLEGAL STATEMENT
  The  statement  was not allowed at this point. It might
  be a numerical expresion where a string expresion was expected or vice
  versa. It might also be a statement that cannot be placed here.

ILLEGAL STRING INDEX
  Trying to read a negative column off a string will most likely cause this.

ILLEGAL VARIABLE TYPE
  You mixed  string  and  integer  variables/ expressions illegally
  or you tried to send to wrong kind of variable to a function.

INTERNAL ERROR
  The library's internal data/structures has not been handled properly by
  the coder of the software you're using. Report this immediately to
  him/her. (See the docs of the software you're controlling with FPL.) This
  is not the FPL programmer's fault.

INSIDE FUNCTION NOT FOUND
  A function that has been prototyped to be an `inside' function was not

                                 - Page 53 -
91.    Error messages

  found!
  Notice that the function *MUST* be prototyped and declared the same way. A
  function prototyped as `int' but declared as `void', will *NOT* be found by
  the FPL interpreter!

INCOMPLETE STATEMENT
  The  statement  just parsed did not include a required action such as a
  variable change or a function call.

MISSING APOSTROPHE
  The program most likely contains a character within single quotes ('),
  where the following quote is missing.

MISSING ARGUMENT
  The  function / keyword  you tried to invoke, requires more arguments!
  (Or refer to the docs of the software you're controlling with FPL.)

MISSING BRACE
  Some places just require braces. I.e block statements that have an initial
  brace or Array assigns that must end with a close
  brace.

MISSING BRACKET
  Array references and other need an open bracket ([) and a close bracket
  (]).

MISSING COLON
  There should be a colon (:) here, but it's not!

MISSING OPERAND
  Making an expression that starts with an operator most likely causes this
  error.

MISSING PARENTHESES
  The statement just interpreted had a lack of parenthesis.

MISSING SEMICOLON
  All statements must be separated with semicolons. This wasn't!

MISSING WHILE
  There is a missing 'while' keyword after the do-while statement!

OUT OF MEMORY
  The system has run out of memory. This isn't your fault, and there is
  nothing you can do about it but decrease memory usage. Note that if *any*
  internal FPL allocation call fails, the program stops with this error code.

OUT OF STACK
  The stack size hit the roof. The program is too recursive!

PARAMETER IS OUT OF RANGE
  The parameter(s) specified must be within a certain range, which you
  clearly did not manage. (Refer to the docs of the action you just tried.)

PROGRAM STOPPED
  The program was stopped by a force outside the library. This is not
  a real error message but more like information.

READ ONLY VIOLATION
  You tried changing the contents of a read-only variable.

SYNTAX ERROR
  Severe error in your writing. Rethink and try again. All  functions ,
  labels or variable  identifiers MUST start with a letter .

TOO MANY PARAMETERS
  Either a function is called with too many parameters, or there is a missing

                                 - Page 54 -
91.    Error messages

  paranthesis after the parameters.

UNBALANCED COMMENT
  There is no corresponding end of comment.

UNEXPECTED END OF PROGRAM
  The program ended where it wasn't supposed to! Probable cause is a
  lack of closing comment sign or lack of a closing paren of some kind.

UNEXPECTED INTEGER STATEMENT
  The interpreter expected a string expression, but read an integer one.

UNEXPECTED STRING STATEMENT
  The interpreter expected an integer expression, but read a string one.

UNKNOWN
  The programmer of the host software sent a strange error code to FPL which
  there is no corresponding error message to!

UNMATCHED BRACE
  This brace has no corresponding one.















































                                 - Page 55 -
91.    Error messages


92.    INDEX of sections

About this manual ..................................................   1. 42
abs ................................................................  40.  2
Addition + .........................................................  21.  1
Assignment expressions .............................................  25.  4
atoi ...............................................................  40. 13
Binary expressions .................................................  20.  3
Bitwise AND & ......................................................  22. 39
Bitwise Exclusive OR ^ .............................................  22. 55
Bitwise inclusive OR | .............................................  23.  4
Bitwise left and right shift << >> .................................  21.  9
Bitwise negation ~ .................................................  19. 50
Blockstatement .....................................................  13. 20
break ..............................................................  27. 13
case ...............................................................  28.  1
char ...............................................................  28. 40
closelib ...........................................................  40. 35
Comma expressions ..................................................  25. 63
Compound assignment ................................................  25. 26
Conditional expressions ............................................  24. 14
Constants ..........................................................  12. 54
continue ...........................................................  28. 56
debug     ..........................................................  30. 22
Declare inside functions ...........................................  10.  1
Decrement -- .......................................................  19. 19
default ............................................................  29. 27
Division / .........................................................  20. 40
do .................................................................  29. 59
else ...............................................................  30. 48
Equality == != .....................................................  22. 15
Error messages .....................................................  51. 56
eval ...............................................................  40. 60
Examples ...........................................................  50. 34
exit ...............................................................  31. 27
export .............................................................  31. 47
Expression statement ...............................................  14. 36
for ................................................................  31. 63
FPL Users Documentation ............................................   1.  0
Funclibs ...........................................................   3. 56
Function calls .....................................................  18. 23
Functions ..........................................................   9. 46
General ............................................................   2. 37
General function use ...............................................  11. 38
Grouping and evaluating ............................................  16. 44
Hints and tricks ...................................................  15. 42
How to reach me ....................................................   2.  1
if .................................................................  33. 24
Increment ++ .......................................................  18. 58
int ................................................................  34. 24
interpret ..........................................................  41. 10
itoa ...............................................................  42.  9
itoc ...............................................................  42. 33
joinstr ............................................................  42. 56
Keywords ...........................................................  14. 62
Line Control .......................................................   4. 16
Logical AND && .....................................................  23. 21
Logical negation ! .................................................  19. 39
Logical OR || ......................................................  23. 51
ltostr .............................................................  43.  8
Multiplication * ...................................................  20. 26
Null statement .....................................................  14. 24
Numeric expressions (and operators) ................................  16. 27
openlib ............................................................  43. 35
Parenthesized Expressions ..........................................  18.  4
Pragmas in FPL .....................................................   4. 58

                                 - Page 56 -
92.    INDEX of sections

Primary expressions ................................................  17. 61
Relational < > <= >= ...............................................  21. 47
Remainder % ........................................................  20. 56
resize .............................................................  34. 48
return .............................................................  35. 40
short ..............................................................  36.  2
Simple assignment = ................................................  25. 15
sprintf ............................................................  44.  4
Statements .........................................................  14.  8
strcmp .............................................................  47. 34
string .............................................................  36. 16
Strings ............................................................   8. 40
strlen .............................................................  47. 60
strncmp ............................................................  48.  5
strstr .............................................................  48. 43
strtol .............................................................  49.  7
substr .............................................................  49. 47
Subtraction - ......................................................  21.  5
switch .............................................................  37. 39
typedef ............................................................  37. 22
Unary Expression ...................................................  18. 43
Unary minus - ......................................................  19. 30
Unary plus + .......................................................  19. 23
Variables ..........................................................   5. 22
while ..............................................................  38. 49

93.    INDEX of keywords

 ++ operator  ......................................................  19. 22
  i ................................................................  36. 23
 About this manual  ................................................   1. 30
 abs        ........................................................  39. 43
 Addition +              ...........................................  20. 13
 Additive              .............................................  17. 11
 Assignment            .............................................  17. 21
 Assignment expressions   ..........................................  16. 41
 atoi       ........................................................  39. 44
 auto      .........................................................  26. 46
 Binary Expressions       ..........................................  16. 40
 Bitwise AND &           ...........................................  20. 14
 Bitwise Exclusive OR  .............................................  17. 16
 Bitwise Exclusive OR ^  ...........................................  20. 15
 Bitwise Inclusive OR  .............................................  17. 17
 Bitwise Inclusive OR |  ...........................................  20. 16
 Bitwise Logical AND   .............................................  17. 15
 Bitwise Negation ~  ...............................................  18. 52
 Bitwise Shift         .............................................  17. 12
 Bitwise Shift << >>     ...........................................  20. 17
 Block       .......................................................  14. 13
 break  ............................................................  15. 19
 break     .........................................................  26. 47
 break       .......................................................  14. 14
 case  .............................................................  29. 58
 case      .........................................................  26. 48
 char  .............................................................  15. 28
 char    ...........................................................  34. 47
 char      .........................................................  26. 49
 closelib()  .......................................................  43. 48
 closelib  .........................................................   4. 12
 closelib   ........................................................  39. 65
 Comma                 .............................................  17. 22
 Comma expressions        ..........................................  16. 43
 comma operator  ...................................................  16. 65
 compound  .........................................................  16.  7
 compound assignment  ..............................................  25. 14
 Conditional           .............................................  17. 20
 Conditional Expressions  ..........................................  16. 42

                                 - Page 57 -
93.    INDEX of keywords

 const     .........................................................  26. 50
 Constants                ..........................................  16. 34
 continue  .........................................................  15. 17
 continue    .......................................................  14. 15
 debug     .........................................................  26. 52
 declaration  ......................................................  52. 31
 Decrement --        ...............................................  18. 53
 default  ..........................................................  28. 39
 default   .........................................................  26. 53
 division  .........................................................  20. 59
 Division /              ...........................................  20. 18
 do  ...............................................................  15.  7
 do        .........................................................  26. 54
 do          .......................................................  14. 16
 else  .............................................................  15.  9
 Equality              .............................................  17. 14
 Equality == !=          ...........................................  20. 19
 Error messages     ................................................   1. 31
 eval  .............................................................  42.  8
 eval       ........................................................  39. 45
 Examples           ................................................   1. 32
 exit  .............................................................  15. 41
 exit      .........................................................  26. 55
 export  ...........................................................  15. 34
 expression1  ......................................................  15. 11
 expression2  ......................................................  15. 11
 expression3  ......................................................  15. 11
 Expression  .......................................................  14. 17
 expressions .......................................................  52. 56
 Expressions        ................................................   1. 17
 for  ..............................................................  15. 11
 for       .........................................................  26. 56
 for         .......................................................  14. 18
 FPL implementation   ..............................................   1. 41
 funclib  ..........................................................  40. 41
 funclibs  .........................................................  40. 59
 Funclibs           ................................................   1. 26
 function  .........................................................  53. 14
 Function calls  ...................................................  18.  3
 functions  ........................................................   2. 55
 Functions          ................................................   1. 18
 General            ................................................   1. 16
 general function usage  ...........................................   9. 50
 General information  ..............................................   1. 38
 Grouping and evaluating  ..........................................  16. 36
 Grouping and Evaluating FPL Expressions  ..........................  17. 65
 Hints and tricks   ................................................   1. 33
 How to reach us    ................................................   1. 34
 identifiers MUST start with a letter  .............................  53. 63
 if  ...............................................................  15. 24
 if        .........................................................  26. 57
 if          .......................................................  14. 19
 Increment ++        ...............................................  18. 54
 Inside functions  .................................................   9. 60
 int  ..............................................................  15. 28
 int     ...........................................................  28. 53
 int       .........................................................  26. 58
 integer  ..........................................................  52. 56
 integer variable  .................................................  12. 34
 Internal functions  ...............................................   9. 65
 interpret  ........................................................  39. 46
 itoa  .............................................................  42. 55
 itoa       ........................................................  39. 47
 itoc       ........................................................  39. 48
 joinstr    ........................................................  39. 49
 keyword  ..........................................................  53. 14
 keyword reference  ................................................  14. 65

                                 - Page 58 -
93.    INDEX of keywords

 keywords  .........................................................   2. 55
 Keywords           ................................................   1. 19
 Line control       ................................................   1. 20
 Logical AND &&          ...........................................  20. 20
 Logical AND           .............................................  17. 18
 Logical Negation !  ...............................................  18. 55
 Logical OR            .............................................  17. 19
 Logical OR ||           ...........................................  20. 21
 long  .............................................................  15. 28
 long      .........................................................  26. 59
 ltostr  ...........................................................  49. 46
 ltostr     ........................................................  39. 50
 More variable declaration details  ................................  15. 37
 Multiplication *        ...........................................  20. 22
 Multiplicative        .............................................  17. 10
 Null        .......................................................  14. 20
 numerical expressions  ............................................  12. 26
 openlib()  ........................................................  40. 46
 openlib  ..........................................................   4.  9
 openlib    ........................................................  39. 64
 outputs all ASCII c ...............................................  36. 26
 Parenthesized Expressions  ........................................  18.  2
 Pragmas            ................................................   1. 24
 precedence  .......................................................  18. 48
 primary  ..........................................................  16. 64
 Primary               .............................................  17.  8
 Primary Expressions      ..........................................  16. 38
 register  .........................................................  26. 60
 Relational            .............................................  17. 13
 Relational < > <= >=    ...........................................  20. 23
 remainder  ........................................................  20. 52
 Remainder %             ...........................................  20. 24
 remainder operator  ...............................................   5. 56
 resize  ...........................................................  15. 32
 resize    .........................................................  26. 61
 return  ...........................................................  15. 41
 return    .........................................................  26. 62
 return      .......................................................  14. 21
 short  ............................................................  15. 28
 short   ...........................................................  28. 54
 short     .........................................................  26. 63
 simple assignment  ................................................  25. 13
 sprintf    ........................................................  39. 51
 statement  ........................................................  15.  7
 Statements  .......................................................  11. 32
 Statements         ................................................   1. 21
 static    .........................................................  26. 64
 strcmp     ........................................................  39. 52
 stricmp    ........................................................  39. 53
 string  ...........................................................  15. 30
 string    .........................................................  26. 65
 string handlings  .................................................  16. 12
 string variable  ..................................................  12. 32
 Strings            ................................................   1. 22
 stristr    ........................................................  39. 58
 strlen     ........................................................  39. 54
 strncmp    ........................................................  39. 55
 strnicmp   ........................................................  39. 56
 strstr     ........................................................  39. 57
 strtol     ........................................................  39. 59
 substr     ........................................................  39. 60
 Subtraction -           ...........................................  20. 25
 switch  ...........................................................  28.  0
 switch    .........................................................  26. 66
 switch      .......................................................  14. 22
 typedef   .........................................................  27.  0
 Unary                 .............................................  17.  9

                                 - Page 59 -
93.    INDEX of keywords

 Unary Expressions        ..........................................  16. 39
 Unary Minus -       ...............................................  18. 56
 Unary Plus +        ...............................................  18. 57
 variable assigns  .................................................  16.  7
 variables  ........................................................  52. 10
 Variables          ................................................   1. 23
 volatile  .........................................................  27.  1
 while  ............................................................  15.  9
 while     .........................................................  27.  2
 while       .......................................................  14. 23
Array assigns ......................................................  53. 19
atoi() .............................................................  42. 32
char ...............................................................  36. 15
Conditional operators ..............................................  52. 23
continue ...........................................................  33. 23
do .................................................................  33. 23
do-while ...........................................................  53. 40
er) and ............................................................  36. 23
eval() .............................................................   9. 45
examp ..............................................................  36. 26
function reference .................................................   9. 44
int  ...............................................................  36. 15
integer expression .................................................  54. 13
itoa() .............................................................  40. 34
ltostr() ...........................................................  42. 32
read-only variable .................................................  53. 59
Resizing ...........................................................  52. 45
statement ..........................................................  53. 34
statements .........................................................  53. 37
strcmp() ...........................................................   9. 45
strcmp() and stricmp() .............................................  48. 42
strcmp and stricmp .................................................  49.  6
string .............................................................  36. 15
string expression ..................................................  54. 10
stristr() ..........................................................  50. 33
strncmp() ..........................................................   9. 45
strncmp and strnicmp ...............................................  47. 59
strstr() ...........................................................  50. 33
strtol() ...........................................................  40. 34
substr() ...........................................................   9. 45
switch() ...........................................................  52. 20
variables. .........................................................  36.  9
while ..............................................................  33. 23