threeadd.y

%{
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

int yylex(void);
int t_count = 1;

void yyerror(char *s)
{
	fprintf(stderr,"%s\n",s);
	return;
}

char * generateToken(int i)
{

char* ch=(char*)malloc(sizeof(char)*5);

sprintf(ch,"t%d",i++);

return ch;
}

%}

%union { double dval; char  ivar[50]; }
%token <ivar> DOUBLE
%token <ivar> NAME
%token <ivar> DIGITS
%type <ivar> expr
%type <ivar> term
%left "+" "-"
%left "*" "/"
%left "(" ")"
%%
program:
	line program			{
							}
	| line					{
							}
	;
line:
	expr 	"\n" 		    {
								t_count =1;
							}
	| NAME "=" expr "\n" 	{

								printf("%s = %s", $3,$1);
								t_count=1;
							}
	;
expr:
	expr "+" expr 			{


								char * x=generateToken(t_count);

								printf("%s = %s + %s",x,$1,$3);
								strcpy($$,x);
							}
	| expr "-" expr 		{


									strcpy($$,generateToken(t_count));
								printf("%s = %s - %s",$$,$1,$3);


							}

	| expr "*" expr 		{

									strcpy($$,generateToken(t_count));
								printf("%s = %s * %s",$$,$1,$3);

							}
	| expr "/" expr 		{

									strcpy($$,generateToken(t_count));
								printf("%s = %s / %s",$$,$1,$3);

							}
	| term 				    {
								strcpy($$, $1);
							}
	| "(" expr ")" 			{

								strcpy($$,generateToken(t_count));
								printf("%s =( %s )" ,$$,$2);

							}
	;
term:

	NAME 					{

								strcpy($$, $1);
							}
	| DIGITS 				{
								strcpy($$, $1);

							}
	;
%%

int main(void)
{

	yyparse();

	return 0;
}