My answer for http://go-tour-jp.appspot.com/#40

gistfile1.go

package main

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

func WordCount(s string) map[string]int {
    tab := make(map[string]int)
    for _, w := range strings.Fields(s) {
        tab[w]++
    }
    return tab
}

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