JefExpression evaluation library v1.0 - by lone -------------------------------------------- How to use ~~~~~~~~~~ ¦ resetVars ----------- void resetVars(void); Resets the variables table. It is necessary to call it prior to evaluate your first expression or variables contents may be random instead of zero ¦ evaluate ---------- double evaluate(char *expression, int *col); Evaluates an expression and returns the result. If a syntax error was encountered during the parsing of the expression, then col will be non-null and col-1 will be the index of the char which triggered the error. Limitations ~~~~~~~~~~~ ¦ you can set only up to 1024 variables. ¦ only decimal and hexadecimal bases available ¦ operators are limited to : + - / * % & | ¦ functions are limited to : sin, cos, tan, asin, acos, atan, atan2, sqr, sqrt, pow, exp, log, log10 Some examples ~~~~~~~~~~~~~ - assignments : pi=3.1415927 a=atan2(cos(pi/4),2) - direct evaluations : cos(pi/4) sin(45) - base notations : 3bh (this is 0x3B) 17d (this is 17) 17dh (this is 0x17D) Adding new functions ~~~~~~~~~~~~~~~~~~~~ The file EVAL.C contains the functions table (fnTable). Just add an entry with the name, the number of parameters, and a pointer to the function body. Implement the body and you're done. If your function ahs more than 2 parameters, you'll need to extend the grammar description file (CAL.Y) to add the FUNCTION3 (and eventually subsequent) token(s) and parsing informations. SCAN.L & CAL.Y ~~~~~~~~~~~~~~ SCAN.L contains description for the lexical analyzer generator (LEX). Use makel.bat to rebuild LEXTAB.C CAL.Y contains the LALR formal grammar description for the parser generator (BISON). Use makey.bat to rebuild CAL_TAB.C Compiling ~~~~~~~~~ Just include all source files to your project, and include EVAL.H into your main source code.