gistfile1.go

package main

import (
	"fmt"
	"log"
)

var input = "(((())))"

func main() {
	if !parseParen() {
		log.Fatal("input does not match")
	}

	fmt.Println("input is valid")
}

func parseParen() bool {
	current := input[0]
	input = input[1:]

	switch current {
	case '(':
		if input[0] == '(' {
			if !parseParen() {
				return false
			}
		}
	default:
		return false
	}

	current = input[0]
	input = input[1:]

	if current == ')' {
		return true
	}

	return false
}