http://tour.golang.org/#41

41.go

package main

import (
    "code.google.com/p/go-tour/wc"
    "strings"
)

func WordCount(s string) map[string]int {
	m := make(map[string]int)
    words := strings.Fields(s)
    for i := 0; i < len(words); i++ {
		m[words[i]] += 1
    }
    return m
}

func main() {
    wc.Test(WordCount)
}