#include <stdio.h>
#include "exprParser.h"

int evalExpr(AST *e)
{
    switch(e->op){
    case NUM: 
	return e->val;
    case PLUS_OP:
	return evalExpr(e->left)+evalExpr(e->right);
    case MINUS_OP:
	return evalExpr(e->left)-evalExpr(e->right);
    default:
	fprintf(stderr,"evalExpr: bad expression\n");
	exit(1);
    }
}