example7.y

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

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

int yywrap()
{
	return 1;
}

main()
{
	yyparse();
}

char *heater="default";

%}

%token TOKHEATER TOKHEAT TOKTARGET TOKTEMPERATURE

%union
{
    int number;
    char *string;
}

%token <number> STATE
%token <number> NUMBER
%token <string> WORD

%%

commands:
    | commands command
    ;

command:
    heat_switch | target_set | heater_select

heat_switch:
    TOKHEAT STATE
    {
        if($2)
            printf("\tHeater '%s' turned on\n", heater);
        else
            printf("\tHeat '%s' turned off\n", heater);
    }
    ;

target_set:
    TOKTARGET TOKTEMPERATURE NUMBER
    {
        printf("\tHeater '%s' temperature set to %d\n", heater, $3);
    }
    ;

heater_select:
    TOKHEATER WORD
    {
        printf("\tSelected heater '%s'\n", $2);
        heater=$2;
    }
    ;