flex-bison-in-action/analyzers/polynomials/polynomials.l

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%{
#include "C:\Users\user\Desktop\УЧЕБА\6_СЕМ\КОМПИЛЯТОРЫ\flex_bison_test\analyzers\polynomials\poly_calc\poly_calc.h"
#include "polynomials.tab.h"
extern FILE *yyin;
char allowed_variable = 0;
int current_line_number = 1;
void yyerror(const char *s) {
fprintf(stderr, "Error at line %i: %s\n", current_line_number, s);
}
%}
%%
"print" { return PRINT; }
";" { return SEMICOLON; }
"=" { return EQUAL; }
[0-9]+ {
init_polynomial(&yylval.poly);
add_term(&yylval.poly, atoi(yytext), 0);
return NUMBER;
}
[a-z] {
if (allowed_variable == 0) {
allowed_variable = yytext[0];
}
else if (yytext[0] != allowed_variable) {
yyerror("Bad variable in expression");
exit(1);
}
init_polynomial(&yylval.poly);
add_term(&yylval.poly, 1, 1);
return VARIABLE;
}
[A-Z] {
yylval.var_name = yytext[0];
return VAR_POLY;
}
[-+*^()] { return yytext[0]; }
[ \t] ;
\n { current_line_number++; }
. { yyerror("Unknown symbol");
exit(1);
}
%%
int yywrap() {
return 1;
}