func (mr *MRWordCount) Map(key string, value string, emitter dmrgo.Emitter) {
lower := strings.ToLower(string(value))
letters := strings.Map(func(r rune) rune {
if r >= 'a' && r <= 'z' {
return r
}
return ' '
},
lower)
trimmed := strings.TrimSpace(letters)
words := strings.Fields(trimmed)
w := uint32(0)
for _, word := range words {
w++
kv := mr.protocol.MarshalKV(word, 1)
emitter.Emit(kv.Key, kv.Value)
}
atomic.AddUint32(&mr.mappedWords, w)
}
func (mr *MRWordCount) Reduce(key string, values []string, emitter dmrgo.Emitter) {
counts := []int{}
mr.protocol.UnmarshalKVs(key, values, &key, &counts)
count := 0
for _, c := range counts {
count += c
}
kv := mr.protocol.MarshalKV(key, count)
emitter.Emit(kv.Key, kv.Value)
}