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EVAL.TXT
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1993-01-29
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EVAL
(c) 1993 by Alexander Walter
WHAT IS IT?
===========
EVAL is a mathematical expression evaluator for QuickBasic. The
expression must be in correct QuickBasic syntax, and can include
functions such as SQR(), ATN(), COS(), etc. Correct hierarchy of
mathematical evaluation is observed. Format of the result is decimal
by default, but can be made hexadecimal or octal.
REGISTRATION INFORMATION
========================
EVAL is offered as shareware. For a very modest $15 registration fee,
you will receive the QuickBasic source code for EVAL. By registering,
you can incorporate this sort of function into your Basic programs.
Register by sending check or money order to:
Alexander Walter
182 ILER Dr.
Middletown, NJ. 07748
(800) 262-0827 USA only
(908) 949-0507 or (908) 671-5080 otherwise
USING EVAL
==========
EVAL reads the command-line, and evaluates it as a valid QuickBasic
mathematics expression. The syntax for using EVAL is:
eval <expression$>
where <expression$> is a mathematical formula in QuickBasic syntax.
For instance, the following are recognized and evaluated:
eval 5 * sqr(30)
eval 10 * log10(0.05)
eval cos(pi/8)
eval sqr(5.6e+3)
eval hex$(32 + &h100)
eval oct$(64 + &o777)
eval 19.93 * (1.05^(-1/3) - 1)
eval sinh(sinh(sinh(.01)))
EVAL honors the algebraic operator hierarchy. At equal levels of
parentheses nesting, algebraic operators are evaluated in the
following order:
^ exponentiation
- negation
*,/ multiplication and division
\ integer division
MOD modulo arithmetic
+,- addition and subtraction
Logical operations: NOT, AND, OR, XOR, EQV, IMP
Relational operations ( =, >, <, <>, <=, >= ) are not presently
supported.
Eval recognizes the following intrinsic QuickBasic functions:
SIN() COS() ATN() SQR() ABS()
INT() LOG() SGN() TAN() CINT()
EXP() MOD AND OR XOR
IMP EQV
The following mathematical functions are also evaluated by EVAL, even
though they are not intrinsic QuickBasic functions. In the source
code, registered users can easily see how to add more functions.
SINH(): Hyperbolic sine
COSH(): Hyperbolic cosine
ARCSIN(): Arc sine
ARCCOS(): Arc cosine
LOG10(): Base 10 logarithm
All sinusoidal functions are evaluated in radians.
The following symbolic constants are also understood by EVAL. In the
source code, registered users can easily see how to add recognition of
other symbolic constants.
PI = 3.141592653589793#
Numeric constants are interpreted as decimal by default, but they can
be interpreted as hexadecimal by prefixing the constant with "&h".
Constants can be interpreted as octal by prefixing them with "&o". For
instance, 65 = &h41 = &o101. The different representations can be
mixed in the same expression.
The format of the output is decimal by default, but can be made
hexadecimal by enclosing the expression with "hex$()". The format can
be made octal by enclosing the expression with "oct$()". For instance:
COMMAND RESULT
--------- ---------
eval 65+65 130
eval hex$(65 + &o101) 82 (hex)
eval oct$(&h41 + &o101) 202 (octal)
With hexadecimal or octal output formatting, any fractional part of
the result is truncated.
MISCELLANEOUS NOTES
===================
If you are using the 4DOS replacement for Microsoft's COMMAND.COM,
4DOS appears to interpret the exponentiation symbol "^", and prevents
it from being passed to EVAL. For this reason, the tilde character "~"
is also recognized as an exponentiation symbol.
EVAL does not process statements that have adjacent exponentiation and
negation, such as "4^-2". Instead, use parentheses such as "4^(-2)".
OTHER SHAREWARE PRODUCTS AVAILABLE:
==================================
FONTEDIT:
--------
View & edit any HP LaserJet bit-mapped soft font. Requires
VGA/EGA/CGA/Herc or AT&T video. Mouse optional. Handles portrait or
landscape, fixed or proportional, and can convert between them.
Handles up to 110 pt (VGA), 80 pt (EGA), 88 pt (Herc & AT&T), or 44 pt
(CGA). Sculpt individual pixels, or use the many built-in special
effects and area shapes. Can import characters from black & white
.PCX, .TIF, or from other soft fonts. Many features.
TT2BMAP:
-------
This program can convert a TrueType font into bitmapped, so that older
DOS programs that don't understand TrueType can still use the latest
fonts.