Question

我正在解析简单的字符串输入，例如：＆＃34; Hello world！： - ）＆＃34;并将它们转换为一个分割单词的数组，并可能做一些修改。我已经生成了以下代码，但它似乎不是非常Ruby的惯用语。我该如何改进呢？

$mapping = Hash[
  "X" => "CODE_X",
  "Y" => "CODE_Y",
  "Z" => "CODE_Z",
]

def translate(input)
  result = []
  tmp = ""
  input.each_char do |c|
    if $mapping.has_key?(c)
      if result != ""
        result << "normal " + tmp
        tmp = ""
      end
      result << "special " + $mapping[c]
    else
      tmp += c
    end
  end
  if tmp != ""
    result << "normal " + tmp
  end
  return result
end

它似乎包含不必要的许多行，使其难以阅读。它做了什么，也许一个例子有帮助：

translate("HelloXworldYZ") =>
["normal Hello", "special CODE_X", "normal world", "special CODE_Y", "special CODE_Z"]

或者用英语：按字符顺序解析字符串并再次连接字符。将它们添加到结果数组中＆＃34; normal＆＃34; + string直到（1）没有更多字符或（2）有一个特殊字符（mapping），它们将字符串添加到数组中并将特殊字符添加为＆＃34; special＆＃34; +映射并继续使用其余字符串。

Answer 1

怎么样

$mapping = { 'X' => 'CODE_X', 'Y' => 'CODE_Y', 'Z' => 'CODE_Z' }

def translate(input)
  input.
    split(/([#{$mapping.keys.map(&Regexp.method(:escape)).join}])/).
    each_slice(2).
    map {|normal, special| [unless normal.empty? then "normal #{normal}" end, "special #{$mapping[special]}"] }.
    map(&:compact).
    flatten
end

translate("HelloXworldYZ")
# => ["normal Hello", "special CODE_X", "normal world", "special CODE_Y", "special CODE_Z"]

请注意，您的简明英语说明和测试用例不符。从您的简单英语描述中，结果应为["normal Hello", "special CODE_X", "normal world", "special CODE_Y", "normal", "special CODE_Z"]。在这种情况下，它甚至更简单：

$mapping = { 'X' => 'CODE_X', 'Y' => 'CODE_Y', 'Z' => 'CODE_Z' }

def translate(input)
  input.
    split(/([#{$mapping.keys.map(&Regexp.method(:escape)).join}])/).
    each_slice(2).
    map {|normal, special| [['normal', unless normal.empty? then normal end].compact.join(' '), "special #{$mapping[special]}"] }.
    flatten
end

translate("HelloXworldYZ")
# => ["normal Hello", "special CODE_X", "normal world", "special CODE_Y", "normal", "special CODE_Z"]

但strscan库可能是更好的选择。

Answer 2

def translate(input,map)
  input.split(/([#{Regexp.escape map.keys.join}])/).map do |part|
    map.key?(part) ? "special #{map[part]}" : "normal #{part}" unless part.empty?
  end.compact
end

p translate( "HelloXworldYZ", 'X'=>'CODE_X', 'Y'=>'CODE_Y', 'Z'=>'CODE_Z' )
#=> ["normal Hello", "special CODE_X", "normal world", "special CODE_Y", "special CODE_Z"]

Answer 3

$mapping = Hash[
  "x" => "CODE_X",
  "y" => "CODE_Y",
  "z" => "CODE_Z",
]

def translate(input)
  $mapping.keys.each { |char| input.gsub!(char, "___#{char}___") } 
  array = input.split(/(___.___)/)
  result = []

  array.each do |word|
    if word.match /___.___/
      result << "special #{$mapping[word[3]]}"
    else
      result << "normal #{word}" unless word.empty?
    end
  end
  result
end

translate("Helloxworldyz")
#=> ["normal Hello", "special CODE_X", "normal world", "special CODE_Y", "special CODE_Z"]

如何编写这个字符串解析更多的Ruby-idiomatic？

3 个答案: