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%{
#include <stdio.h>
#include <math.h>
#include "symtab.h"
#include <string.h>
%}
%union {
char *string;
double dval;
}
%token <string> VAR
%token <dval> TAL
%token LOG EXP SQRT VAR_BEGIN
%left '-' '+'
%right LOG EXP SQRT
%left '*' '/'
%right UMINUS
%type <dval> expression
%%
statement_list: statement '\n'
| statement_list statement '\n' ;
statement: expression {printf("= %f\n",$1);}
| VAR_BEGIN VAR '=' expression {symnode_t *n = sym_lookup($2);
if( !n ) {n = sym_insert($2); }
n->value = $4;};
expression: expression '+' expression {$$ = $1 + $3;}
| expression '-' expression {$$ = $1 - $3;}
| expression '*' expression {$$ = $1 * $3;}
| expression '/' expression {if ($3 == 0.0)
yyerror("divide dy zero");
else $$ = $1 / $3;}
| '-' expression %prec UMINUS {$$ = - $2;}
| '(' expression ')' {$$= $2;}
| LOG expression {$$ = log($2);}
| EXP expression {$$ = exp($2);}
| SQRT expression {$$ = sqrt($2);}
| TAL {$$ = $1;}
| VAR {symnode_t *n = sym_lookup($1);
if( !n ) { yyerror("Var not found"); } else { $$ = n->value;} };
%%
int main()
{
yyparse();
}
|
