%{

#include <stdio.h>
#include <iostream>
#include "parser.tab.hh"        /* bison-generated header with YY[SL]TYPE */
using namespace std;

#define yyerror(msg) errFunc(msg, &yylloc)

int yylex(YYSTYPE *, YYLTYPE *);

extern FILE * yyin;

void errFunc(const char * str, YYLTYPE * yyllocp);

int yywrap()
{
    return 1;
}

%}

%pure-parser
%locations
%error-verbose

    /* operators */
%token ASSIGN;
%token DEQUALS;
%token DIVIDE;
%token EQUALS;
%token GREATER;
%token LESS;
%token MATCH;
%token MINUS;
%token MOD;
%token PLUS;
%token STAR;

    /* punctuation */
%token COLON;
%token COMMA;
%token DCOLON;
%token DOLLAR;
%token DOT;
%token FROM;
%token QUESTION;
%token SEMICOLON;

%token LCURLY;
%token RCURLY;
%token LBRACKET;
%token RBRACKET;
%token LPAREN;
%token RPAREN;

    /* literals */
%token INT_LITERAL;
%token REAL_LITERAL;

    /* primitive types */
%token BYTE;
%token UBYTE;
%token CHAR;
%token WCHAR;
%token INT;
%token UINT;
%token LONG;
%token ULONG;

    /* keywords */
%token IMPORT;
%token MODULE;
%token RETURN;
%token STRUCT;

    /* identifiers */
%token IDENTIFIER;

%%

program_items: /* empty */
             | program_item program_items
             ;

program_item: module_declaration
            | import
            | variable_declaration
            | function
            ;

module_declaration: MODULE module_name SEMICOLON
                  ;

module_name: IDENTIFIER module_name_more
           ;

module_name_more: /* empty */
                | DOT IDENTIFIER module_name_more
                ;

import: IMPORT import_name SEMICOLON
      ;

import_name: IDENTIFIER import_name_more
           ;

import_name_more: /* empty */
                | DOT import_name_more_more
                ;

import_name_more_more: IDENTIFIER import_name_more
                     | STAR
                     ;

function: type IDENTIFIER LPAREN parameter_list RPAREN LCURLY function_items RCURLY
        ;

function_items: /* empty */
              | statement function_items
              ;

parameter_list: /* empty */
              | variable_spec parameter_list_more
              ;

parameter_list_more: /* empty */
                   | COMMA variable_spec parameter_list_more
                   ;

primitive_type: BYTE
              | UBYTE
              | CHAR
              | WCHAR
              | INT
              | UINT
              | LONG
              | ULONG
              ;

struct_type: STRUCT LCURLY struct_items RCURLY
           ;

struct_items: /* empty */
            | struct_item struct_items
            ;

struct_item: variable_declaration
           ;

variable_declaration: variable_spec SEMICOLON;
                    ;

variable_spec: type IDENTIFIER
             ;

ptr_type: type STAR
        ;

array_type: type LBRACKET RBRACKET
          ;

type: primitive_type
    | ptr_type
    | struct_type
    | array_type
    | IDENTIFIER
    ;

statement: expression SEMICOLON
         | return_statement SEMICOLON
         ;

return_statement: RETURN expression
                ;

expression: assign_expr
          ;

assign_expr: lvalue ASSIGN expression
           ;

lvalue: IDENTIFIER
      ;

%%

void parse(const char * fileName)
{
    yyin = fopen(fileName, "r");
    if (yyin == NULL)
    {
        cerr << "Failed to open file '" << fileName << "'" << endl;
        return;
    }
    if (yyparse())
    {
        cerr << "Aborting." << endl;
        exit(1);
    }
}

void errFunc(const char * str, YYLTYPE * yyllocp)
{
    fprintf(stderr, "error: %s: line %d, column %d\n",
        str,
        yyllocp->first_line,
        yyllocp->first_column);
}