Simple database server in Go

keyValue.go

/* keyValue.go */
package main

import (
  "fmt"
	"net/http"
	"net/url"
	"regexp"
	"strings"
)


var validSetQuery = regexp.MustCompile("^[a-zA-Z0-9-_ ]+=[a-zA-Z0-9-_ ]+$")
var validGetQuery = regexp.MustCompile("^[a-zA-Z0-9-_ ]+$")
var pairs = map[string]string{}

// handler for setting key-value pairs
func setHandler(w http.ResponseWriter, r *http.Request) {
	descapedQuery, _ := url.QueryUnescape(r.URL.RawQuery)
	if validSetQuery.MatchString(descapedQuery) {
		query := strings.Split(descapedQuery, "=")
		pairs[query[0]] = query[1]
		fmt.Fprint(w, "(", query[0], ", ", query[1], ") successfully written.")
	} else {
		fmt.Fprint(w, "Please enter a valid key-value pair in the form \"/set?key=value\".")
	} 
	return
}

// handler for getting the value for a given key
func getHandler(w http.ResponseWriter, r *http.Request) {
	query, _ := url.QueryUnescape(r.URL.RawQuery)
	if validGetQuery.MatchString(query) {
		value, ok := pairs[query]
		if ok {
			fmt.Fprint(w, value)
		} else {
			fmt.Fprint(w, "There is no matching key in the data. Please try again.")
		}	
	} else {
		fmt.Fprint(w, "Please enter a valid key for lookup in the form \"/get?key\".")
	}
	return
}

func main() {
  http.HandleFunc("/set", setHandler)
  http.HandleFunc("/get", getHandler)
  http.ListenAndServe(":4000", nil)
}