Go - コレクション - 守備範囲が広いマップ - 文章と単語の出現頻度、文字列、空白文字で分割、小文字化、文字の除去、stringパッケージ、Fields関数、ToLower関数、Trim関数

入門Goプログラミング
原著: Get Programming with Go
楽天ブックス Yahoo!

開発環境

• macOS Catalina - Apple (OS)
• Emacs (Text Editor)
• Windows 10 Pro (OS)
• Visual Studio Code (Text Editor)
• Go (プログラミング言語)

入門Goプログラミング (Nathan Youngman(著)、Roger Peppé(著)、吉川 邦夫(監修, 翻訳)、翔泳社)のUNIT 4(コレクション)、LESSON 19(守備範囲が広いマップ)の練習問題の解答を求めてみる。

コード

package main

import (
 "fmt"
 "strings"
)

func main() {
 s := "As far as eye could reach he saw nothing but the stems of the great plants about him receding in the violet shade, and far overhead the multiple transparency of huge leaves filtering the sunshine to the solemn splendour of twilight in which he walked. Whenever he felt able he ran again; the ground continued soft and springy, covered with the same resilient weed which was the first thing his hands had touched in Malacandra. Once or twice a small red creature scuttled across his path, but otherwise there seemed to be no life stirring in the wood; nothing to fear—except the fact of wandering unprovisioned and alone in a forest of unknown vegetation thousands or millions of miles beyond the reach or knowledge of man."
 count := make(map[string]int)
 for _, word := range strings.Fields(s) {
  word = strings.ToLower(strings.Trim(word, ".?,"))
  count[word]++
 }
 fmt.Println("2回以上出現した単語")
 for k, v := range count {
  if v >= 2 {
   fmt.Printf("%-10v %2v回\n", k, v)
  }
 }
}

入出力結果(Zsh、PowerShell、Terminal)

% go build words.go
% ./words 
2回以上出現した単語
a           2回
which       2回
but         2回
he          4回
to          3回
as          2回
far         2回
in          5回
or          3回
nothing     2回
reach       2回
and         3回
his         2回
the        12回
of          7回
% ./words
2回以上出現した単語
far         2回
the        12回
which       2回
he          4回
to          3回
or          3回
nothing     2回
as          2回
reach       2回
a           2回
his         2回
but         2回
in          5回
of          7回
and         3回
%