%{

#include <stdlib.h>
#include <stdio.h>

int linecount = 0;

void yyerror(char *s)
{
  fprintf(stderr,"file is not okay -- problem at line %d\n",linecount);
  exit(1); 
}

int yywrap()
{
  return 1;
}

%}

%token ID 
%token PROGRAM 
%token END 
%token VARIABLES 
%token VAR
%token STATEMENTS
%token IF
%token THEN
%token ELSE
%token WHILE
%token LBRACE 
%token RBRACE 
%token COLON 
%token SEMICOLON
%token FUNCTIONS
%token COMMA
%token DEFINE
%token LPARENTHESIS
%token RPARENTHESIS

%%

program : PROGRAM ID variablesSection functionsSection statementsSection END ;


variablesSection : VARIABLES LBRACE variableDeclarations RBRACE ;

variableDeclarations :  | variableDeclarations variableDeclaration ;

variableDeclaration : ID COLON ID SEMICOLON {printf("emitting var %s of type %s\n",$3,$1);} ;


functionsSection : FUNCTIONS LBRACE functionDeclarations RBRACE ;

functionDeclarations : | functionDeclarations functionDeclaration ; 

functionDeclaration : DEFINE ID COLON ID LPARENTHESIS argsList RPARENTHESIS LBRACE statements RBRACE ;


statementsSection : STATEMENTS LBRACE statements RBRACE ;

statements : | statements statement ;

statement : VAR variableDeclaration | whileLoop | ifStruct | subroutineCall SEMICOLON ;


whileLoop : WHILE LPARENTHESIS subroutineCall RPARENTHESIS LBRACE statements RBRACE ;

ifStruct : IF LPARENTHESIS subroutineCall RPARENTHESIS LBRACE statements RBRACE  ;
           |
           IF LPARENTHESIS subroutineCall RPARENTHESIS LBRACE statements RBRACE ELSE LBRACE statements RBRACE ;

subroutineCall : ID LPARENTHESIS callArgsList RPARENTHESIS ;


argsList : | argPair | argsList COMMA argPair ;

argPair : ID ID ;


callArgsList : | ID |  callArgsList COMMA ID ;


%%

int main(int argc, char **argv)
{
  //  yydebug = 1;
  yyparse();
  printf("input is okay\n");
}