parser.y

%require "3.8"

%code top {
  #include <stdio.h>  /* fprintf. */
  #include "ast.h"

  int yylex(char **content);
  void yyerror(char **content, char const *);
  parser_ast *ast = NULL;
}

%param {char **content}

%define api.header.include {"parser.h"}
%define api.value.type {parser_t}

%token <number> TOK_NUMBER
%type  <ast> expr

%left '-' '+'

%%

line:
  %empty
|  expr { ast = $1; }
;

expr:
    TOK_NUMBER    { $$ = create_ast("NUMBER", $1); }
|   expr '+' expr { $$ = create_ast_operation("OPERATION_PLUS", $1, $3); }
|   expr '-' expr { $$ = create_ast_operation("OPERATION_MINUS", $1, $3); }
;

%%

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

parser_ast* parse(char *content) {

    yyparse(&content);

    return ast;
}

int main(int argc, char *argv[])
{
    ast = parse(argv[1]);
    if (ast == NULL) {
       return 1;
    }

    dump_ast(ast, 0);

    return 0;
}