%{

#include <stdio.h>

#include <stdlib.h>

#include "y.tab.h" // obtained from yacc file

int i;

#define border printf("\n"); for(i=0; i<=80; ++i) { putchar('-'); } printf("\n");

int yyerror(char *errorMsg);

void success(char *successMsg);

"print" return (PRINT);

"and"|"assert"|"break"|"class"|"def"|"del"|"elif" return (KEYWORD);

"else"|"except"|"exec"|"finally"|"for"|"from"|"global" return (KEYWORD);

"if"|"import"|"in"|"is"|"lambda"|"not"|"or"|"pass"|"raise" return (KEYWORD);

"return"|"try"|"while"|"with"|"yield" return (KEYWORD);

[0-9]+ return NUMBER;

[_a-zA-Z][_a-zA-Z0-9]* return ID ;

[ \t] ;

\= return (EQ);

\+ return (PLUS);

\- return (MINUS);

\* return (MUL);

\/ return (DIVIDE);

\( return (LBRACKET);

\) return (RBRACKET);

\; return (SEMICOLON);

\"([^\"\n])*\" return (STRING_LIT);

\'([^\'\n])*\' return (STRING_VAR);

. { printf("\nunidentified token %s\n", yytext); exit(1); }

int main() {

printf("\n--------------------------- PYTHON EXPRESSION PARSER ---------------------------\n");

printf("\nEnter a python expression : \n");

yyparse();

return 0;

}

void success(char *successMsg) {

fprintf(stderr, "\n%s\n", successMsg);

border;

}

int yyerror(char *errorMsg){

fprintf(stderr, "\n%s\n", errorMsg);

border;

}

int yywrap() {

return 1;

}