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The 640 Meg Shareware Studio CD-ROM Volume II (Data Express)(1993).ISO
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FACILIS.IM
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1985-03-05
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Facilis Implementation Manual
Version 0.20 File: FACILIS.IM
Updated: 15 Feb 85
INTRODUCTION
Facilis is implemented in Turbo Pascal, an excellent commercial compiler
sold by Borland International. You must have Turbo to compile the Facilis
source files; it is not capable of compiling itself.
The source code is contained in three files:
FACILIS.PAS - main program
BLOCK.PAS - an include file
INTERPRT.PAS - an include file
The implementation exploits certain non-standard features of Turbo, such
as the MEM array, and utilizes the segment:offset addressing of the 8088.
Modifications may be required to compile under a different Pascal compiler
or for a different processor. Also, version 0.20 has been modifed with
an assembly level jump table to speed up run time execution.
This implementation was done on an IBMPC running the PC-DOS version of
Turbo. However, it makes no explicit calls to DOS, and should compile
under the CP/M-86 version of Turbo with little or no change.
COMPILING THE COMPILER
The source files may be placed on any drive(s). A RAM drive is recommended
to save wear on your disks. Turbo expects to find BLOCK.PAS and INTERPRT.PAS
on the logged drive. To override this assumption, you can place explicit drive
specifiers in the {$I include directives within FACILIS.PAS.
Run Turbo. From the main menu, enter FACILIS.PAS as the Main file.
Go to the Options menu and choose the Com option. (Because it uses overlays,
Facilis cannot be compiled in memory.) Quit to the main menu and Compile.
Compilation results in two files: FACILIS.COM and an overlay file,
FACILIS.000. These files will be written to the drive that FACILIS.PAS is
loaded from, not necessarily the logged drive. These are big files. Allow
enough space or you will get an error writing to disk, aborting compilation.
SYNTAX DIAGRAMS
(All words in caps are required key words)
program
+----------->----------------------+
| |
---> PROGRAM ---> identifier -+-> ( ---> identifier list ---> ) -+-> ; ---+
|
+-------------------------------------------------------------<-+
|
+--> block ------> .
block
--+---> CONST ---+---> identifier --------> = ---> constant ---> ; ---+
| ^ |
+-<------------+--------------------------------------------------<-+
|
+---> TYPE ----+---> identifier --------> = ---> type -------> ; ---+
| ^ |
+-<------------+--------------------------------------------------<-+
|
+---> VAR ---------> identifier list ---> : ---> type -------> ; ---+
| |
+-<---------------------------------------------------------------<-+
|
v
|
+-+-> PROCEDURE ---> identifier --------> formal parameter list ---+
| ^ |
v | |
+-+-<----------- ; <------- block <---------- ; <-------------------+
| |
+---> FUNCTION ----> identifier ----> formal parameter list ---+ ^
| | |
| +-<----------------------------------------------------+ |
| | |
| +---> : ----------> type identifier ---------------------->-+
|
+---> BEGIN -------> statement sequence -----> END ----->
type
--+-----------------------> type identifier --------------------------------+->
| |
+--> ARRAY --> [ -+> constant --> .. --> constant -+> ] --> OF --> type --+
| | | |
| +-------------- , <-------------+ |
| |
| +->-------------------------------------->-+ |
| | | |
+--> RECORD ---+-+-> identifier list ---> : ---> type -+--+-> END ------>-+
| |
+----------------------- ; <----------+
formal parameter list
+->--------------------------------------------------------------------->-+
| |
--+-> ( -+-+->-------+--> identifier list --> : --> type identifier -+-> ) -+->
| | | |
| +-> VAR --+ |
| |
+-<--------------------------------- ; <--------------------+
identifier list
-----------------+---> identifier ----+---------------------------->------->
| |
+--------- , <---------+
identifier
-----------------> letter -----+--->-----------+--------------------->------->
^ |
+--- letter <---+
| |
+--- digit <---+
| |
+---- _ <-----+
statement sequence
-----------------+---> statement ----+---------------------------->------->
^ |
+--------- ; <---------+
statement
--+--+-> variable -------------+--> := ---------> expression ------------->-+->
| | | |
| +-> function identifier --+ |
| |
+----> procedure identifier ----+---> actual parameter list ---+-------->-+
| | | |
| +--->--------------------------+ |
| |
+----> BEGIN ------> statement sequence ------> END -------------------->-+
| |
| +->---------------------->-|
| | |
+--> IF --> expression --> THEN --> statement -+-> ELSE --> statement -->-+
| |
| +--->-------------------------------+ |
| | | |
+-> CASE -> expression -> OF +-+-> constant +-> : -> statement +-+-> END -+
| | | | |
| +----- , <---+ | |
| | | |
| +--------------- ; <------------+ |
| |
+----> WHILE ----> expression ------> DO ------> statement ------------->-+
| |
+----> REPEAT ---> statement sequence ---> UNTIL ---> expression ------->-+
| |
+----> FOR ------> variable identifier ---> := ---> expression --+ |
| | |
| +----<----------------------------------------------------<-+ |
| | |
| +--+-> TO -------+--> expression ---> DO ---> statement ----------->-+
| | | |
| +-> DOWNTO ---+ |
| |
+---->------------------------------------------------------------------>-+
expression
---> simple expression --+---+---+---+---+---+------------------------->-+-->
| | | | | | |
v v v v v v |
= <> < > >= <= |
| | | | | | |
+---+---+---+---+---+--> simple expression --->-+
simple expression
---+-->-----+--> term ----+--->-----------------+----+----+---------->------>
| | | | | |
+--> + --+ | v v v
| | | + - OR
+--> - --+ | | | |
+---- term <----------+----+----+
term
------> factor -----------+--->------------+----+----+----+----+----->------>
| | | | | |
| v v v v v
| * / DIV MOD AND
| | | | | |
+--- factor <----+----+----+----+----+
factor
---+--> unsigned constant --------------------------------------------->-+-->
| |
+--> variable ------------------------------------------------------>-+
| |
+--> function identifier ------> actual parameter list ------------->-+
| |
+--> ( -------> expression ----> ) --------------------------------->-+
| |
+--> NOT -----> factor --------------------------------------------->-+
actual parameter list
------> ( ------+---> expression ---+------> ) ---------------------->------>
| |
+-------- , <-------+
variable
----> variable identifier ---+----+--->------------------------------>------->
| |
| +---> [ --+--> expression --+--> ] --+
^ | | | |
| | +------- , <------+ |
| | |
| +---> . -----> field identifier -->--+
| |
+---<----------------------------------<--+
constant
---+---+-->-----+-----+---> unsigned number ---------------->-+------>------>
| | | | |
| +--> + --+ | |
| | | +---> constant identifier ------------>-+
| +--> - --+ |
| |
+----------------------> literal string ----------------->-+
unsigned constant
---+------> constant identifier ---------------------------->-+------>------>
| |
+------> unsigned number -------------------------------->-+
| |
+------> literal string --------------------------------->-+
literal string
-------> ' -----+----------->----------+-----> ' ------------>-------------->
| |
+-----> character -----+
| |
+-----------<----------+
unsigned number
---> unsigned integer ---+--->----------------------------------+->-+------->
| | |
+---> . ----> unsigned integer --+--->-+ |
| | |
v | |
+---<-------------------------<--+ |
| |
+---> E --+-->-----+-> unsigned integer ->-+
| |
+--> + --+
| |
+--> - --+
unsigned number
------------------------+-----> digit -----+------------------------->------>
| |
+-----<------------+
RESERVED WORDS
The following symbols are reserved and cannot be used as identifiers:
AND DOWNTO IF OR THEN
ARRAY ELSE IN PACKED TO
BEGIN END LABEL PROCEDURE TYPE
CASE FILE MOD PROGRAM UNTIL
CONST FOR NIL RECORD VAR
DIV FUNCTION NOT REPEAT WHILE
DO GOTO OF SET WITH
OPERATION CODES
These are shown in the list file when the T option is selected.
Operations take zero, one, or two operands: x represents an 8-bit operand,
usually a level number; y represents a 16-bit quantity, such as an address
or an integer.
Code Action
0 x y Load address
1 x y Load value
2 x y Load indirect
3 x y Update DISPLAY
4 not used
5 not used
6 not used
7 y Concatenate
8 y Standard functions
9 y Add y to the element on top of the stack
10 y Jump to y (unconditional)
11 y Jump to y if stack top false
12 y Jump to y (case table) and select entry
13 y Entry in case table ... NOT EXECUTABLE
14 y For loop entry test - UP
15 y For loop retry test - UP
16 y For loop entry test - DOWN
17 y For loop retry test - DOWN
18 y Mark stack
19 y Call user procedure
20 y Indexed fetch (element size > 1)
21 y Indexed fetch
22 y Load block
23 y Copy block
24 y Load literal
25 y Load real
26 y Float
27 y Read (y denotes type .. 1 integer, 2 real, 4 char)
28 y Write string
29 y Write - default field widths
30 y Write - defined field widths
31 y Assign string (of length 1) to char
32 y Relation operators for strings
33-130 not used
131 Halt
132 Exit procedure
133 Exit function
134 Fetch
135 Not
136 - integer (unary)
137 Write real - defined field
138 Store
139 Real =
140 Real <>
141 Real <
142 Real <=
143 Real >
144 Real >=
145 Integer =
146 Integer <>
147 Integer <
148 Integer <=
149 Integer >
150 Integer >=
151 Or
152 + integer
153 - integer
154 + real
155 - real
156 And
157 * integer
158 Div
159 Mod
160 * real
161 /
162 Readln
163 Writeln
164 - real (unary)
165 Index string
166 Assign string temporary to string
167 Convert array to string
168 Assign character to string
169 Assign string to string
170 Write string
171 Write string temporary
172 Value parameter - string
173 Value parameter - string temporary
174 Convert string to array
175 Convert string temporary to array
176 Write string - defined field
177 Write string temporary - defined field
178-255 not used
array
176 Write string - defi
