/* SI 413 Fall 2011
 * Class 12
 * This file is bcalc.ypp */
 
%{
#include <vector>
#include <string>
#include <iostream>
using namespace std;
 
#include "parsetree.hpp"
 
ParseTree* PT = NULL;
 
int yylex(); 
int yyerror(const char *p) { cerr << "Parse error!" << endl; }
 
%}
 
 
%token NUM OPA OPM LP RP STOP COMP BOP VAR ASN
 
%%
start: run { PT = $$; }
 
run: stmt run { $$ = new ParseTree("run",$1,$2); }
| stmt { $$ = new ParseTree("run",$1); }
 
stmt: ares STOP { $$ = new ParseTree("stmt",$1,$2); }
 
ares: VAR ASN bres { $$ = new ParseTree("ares",$1,$2,$3); }
| bres { $$ = new ParseTree("ares",$1); }
 
bres: res { $$ = new ParseTree("bres",$1); }
| bres BOP res { $$ = new ParseTree("bres",$1,$2,$3); }
 
res: exp { $$ = new ParseTree("res",$1); }
| res COMP exp { $$ = new ParseTree("res",$1,$2,$3); }
 
exp: exp OPA term { $$ = new ParseTree("exp",$1,$2,$3); }
| term { $$ = new ParseTree("exp",$1); }
 
term: term OPM factor { $$ = new ParseTree("term",$1,$2,$3); }
| factor { $$ = new ParseTree("term", $1); }
 
factor: NUM  { $$ = new ParseTree("factor",$1); }
| LP bres RP { $$ = new ParseTree("factor",$1,$2,$3); }
| VAR        { $$ = new ParseTree("factor",$1); }
 
%%
int main()
{
  yyparse();
  PT->writeDot("bcalc.dot");
  return 0;
}