Ruby 正则表达式提取单词

Question

我目前正在努力想出一个正则表达式，它可以将字符串分割成单词，其中单词被定义为由空格包围或用双引号括起来的字符序列。我正在使用 String#scan

例如，字符串：

'   hello "my name" is    "Tom"'

应该匹配单词：

hello
my name
is
Tom

我设法使用以下方法匹配用双引号括起来的单词：

/"([^\"]*)"/

但我不知道如何合并包围的单词通过空格字符来获取“你好”、“是”和“汤姆”，同时不会搞砸“我的名字”。

任何对此的帮助将不胜感激！

Answer 1

result = '   hello "my name" is    "Tom"'.split(/\s+(?=(?:[^"]*"[^"]*")*[^"]*$)/)

会为你工作。它将打印

=> ["", "hello", "\"my name\"", "is", "\"Tom\""]

Just 忽略空字符串。

解释

"
\\s            # Match a single character that is a “whitespace character” (spaces, tabs, and line breaks)
   +             # Between one and unlimited times, as many times as possible, giving back as needed (greedy)
(?=           # Assert that the regex below can be matched, starting at this position (positive lookahead)
   (?:           # Match the regular expression below
      [^\"]          # Match any character that is NOT a “\"”
         *             # Between zero and unlimited times, as many times as possible, giving back as needed (greedy)
      \"             # Match the character “\"” literally
      [^\"]          # Match any character that is NOT a “\"”
         *             # Between zero and unlimited times, as many times as possible, giving back as needed (greedy)
      \"             # Match the character “\"” literally
   )*            # Between zero and unlimited times, as many times as possible, giving back as needed (greedy)
   [^\"]          # Match any character that is NOT a “\"”
      *             # Between zero and unlimited times, as many times as possible, giving back as needed (greedy)
   \$             # Assert position at the end of a line (at the end of the string or before a line break character)
)
"

您可以像这样使用reject来避免

result = '   hello "my name" is    "Tom"'
            .split(/\s+(?=(?:[^"]*"[^"]*")*[^"]*$)/).reject {|s| s.empty?}

打印空字符串

=> ["hello", "\"my name\"", "is", "\"Tom\""]

Answer 2

text = '   hello "my name" is    "Tom"'

text.scan(/\s*("([^"]+)"|\w+)\s*/).each {|match| puts match[1] || match[0]}

产生：

hello
my name
is
Tom

解释：

0 个或多个空格后跟

单个

双引号内的一些单词或

单词

后跟 0 个或多个空格

Answer 3

您可以尝试这个正则表达式：

/\b(\w+)\b/

它使用 \b 来查找单词边界。这个网站 http://rubular.com/ 很有帮助。