regex - 优化正则表达式以解析中文拼音

Question

我有一个工作正则表达式来解析匹配每个有效拼音但不匹配无效拼音的拼音。我想知道如何优化它。

^(?P<initial>ch|zh|sh|r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z|)
 (?P<final>
   (?:(?<=ch)uang|(?<=ch)ang|(?<=ch)eng|(?<=ch)ong|(?<=ch)uai|(?<=ch)uan|(?<=ch)ai|(?<=ch)an|(?<=ch)ao|(?<=ch)en|(?<=ch)ou|(?<=ch)ua|(?<=ch)ui|(?<=ch)un|(?<=ch)uo|(?<=ch)a|(?<=ch)e|(?<=ch)i|(?<=ch)u)
  |(?:(?<=zh)uang|(?<=zh)ang|(?<=zh)eng|(?<=zh)ong|(?<=zh)uai|(?<=zh)uan|(?<=zh)ai|(?<=zh)an|(?<=zh)ao|(?<=zh)ei|(?<=zh)en|(?<=zh)ou|(?<=zh)ua|(?<=zh)ui|(?<=zh)un|(?<=zh)uo|(?<=zh)a|(?<=zh)e|(?<=zh)i|(?<=zh)u)
  |(?:(?<=sh)uang|(?<=sh)ang|(?<=sh)eng|(?<=sh)uai|(?<=sh)uan|(?<=sh)ai|(?<=sh)an|(?<=sh)ao|(?<=sh)ei|(?<=sh)en|(?<=sh)ou|(?<=sh)ua|(?<=sh)ui|(?<=sh)un|(?<=sh)uo|(?<=sh)a|(?<=sh)e|(?<=sh)i|(?<=sh)u)
  |(?:(?<=c)ang|(?<=c)eng|(?<=c)ong|(?<=c)uan|(?<=c)ai|(?<=c)an|(?<=c)ao|(?<=c)en|(?<=c)ou|(?<=c)ui|(?<=c)un|(?<=c)uo|(?<=c)a|(?<=c)e|(?<=c)i|(?<=c)u)
  |(?:(?<=b)ang|(?<=b)eng|(?<=b)ian|(?<=b)iao|(?<=b)ing|(?<=b)ai|(?<=b)an|(?<=b)ao|(?<=b)ei|(?<=b)en|(?<=b)ie|(?<=b)in|(?<=b)a|(?<=b)i|(?<=b)o|(?<=b)u)
  |(?:(?<=d)ang|(?<=d)eng|(?<=d)ian|(?<=d)iao|(?<=d)ing|(?<=d)ong|(?<=d)uan|(?<=d)ai|(?<=d)an|(?<=d)ao|(?<=d)ei|(?<=d)en|(?<=d)ia|(?<=d)ie|(?<=d)iu|(?<=d)ou|(?<=d)ui|(?<=d)un|(?<=d)uo|(?<=d)a|(?<=d)e|(?<=d)i|(?<=d)u)
  |(?:(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)a|(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)ai
  |(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)an|(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)ang
  |(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)ao|(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)e

为了便于阅读，上面是一个缩写版本。整个表达式可以在这篇文章的末尾找到。

我特别想知道是否将两个或多个前缀传递给结束匹配器会提高性能：

 (<=ch|zh|sh)uang|(<=ch|zh|sh)ang...

感谢您的时间和建议。

整个正则表达式：

 ^(?P<initial>ch|zh|sh|r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z|)(?P<final>(?:(?<=ch)uang|(?<=ch)ang|(?<=ch)eng|(?<=ch)ong|(?<=ch)uai|(?<=ch)uan|(?<=ch)ai|(?<=ch)an|(?<=ch)ao|(?<=ch)en|(?<=ch)ou|(?<=ch)ua|(?<=ch)ui|(?<=ch)un|(?<=ch)uo|(?<=ch)a|(?<=ch)e|(?<=ch)i|(?<=ch)u)|(?:(?<=zh)uang|(?<=zh)ang|(?<=zh)eng|(?<=zh)ong|(?<=zh)uai|(?<=zh)uan|(?<=zh)ai|(?<=zh)an|(?<=zh)ao|(?<=zh)ei|(?<=zh)en|(?<=zh)ou|(?<=zh)ua|(?<=zh)ui|(?<=zh)un|(?<=zh)uo|(?<=zh)a|(?<=zh)e|(?<=zh)i|(?<=zh)u)|(?:(?<=sh)uang|(?<=sh)ang|(?<=sh)eng|(?<=sh)uai|(?<=sh)uan|(?<=sh)ai|(?<=sh)an|(?<=sh)ao|(?<=sh)ei|(?<=sh)en|(?<=sh)ou|(?<=sh)ua|(?<=sh)ui|(?<=sh)un|(?<=sh)uo|(?<=sh)a|(?<=sh)e|(?<=sh)i|(?<=sh)u)|(?:(?<=c)ang|(?<=c)eng|(?<=c)ong|(?<=c)uan|(?<=c)ai|(?<=c)an|(?<=c)ao|(?<=c)en|(?<=c)ou|(?<=c)ui|(?<=c)un|(?<=c)uo|(?<=c)a|(?<=c)e|(?<=c)i|(?<=c)u)|(?:(?<=b)ang|(?<=b)eng|(?<=b)ian|(?<=b)iao|(?<=b)ing|(?<=b)ai|(?<=b)an|(?<=b)ao|(?<=b)ei|(?<=b)en|(?<=b)ie|(?<=b)in|(?<=b)a|(?<=b)i|(?<=b)o|(?<=b)u)|(?:(?<=d)ang|(?<=d)eng|(?<=d)ian|(?<=d)iao|(?<=d)ing|(?<=d)ong|(?<=d)uan|(?<=d)ai|(?<=d)an|(?<=d)ao|(?<=d)ei|(?<=d)en|(?<=d)ia|(?<=d)ie|(?<=d)iu|(?<=d)ou|(?<=d)ui|(?<=d)un|(?<=d)uo|(?<=d)a|(?<=d)e|(?<=d)i|(?<=d)u)|(?:(?<=g)uang|(?<=g)ang|(?<=g)eng|(?<=g)ong|(?<=g)uai|(?<=g)uan|(?<=g)ai|(?<=g)an|(?<=g)ao|(?<=g)ei|(?<=g)en|(?<=g)ou|(?<=g)ua|(?<=g)ui|(?<=g)un|(?<=g)uo|(?<=g)a|(?<=g)e|(?<=g)u)|(?:(?<=f)ang|(?<=f)eng|(?<=f)iao|(?<=f)an|(?<=f)ei|(?<=f)en|(?<=f)ou|(?<=f)a|(?<=f)o|(?<=f)u)|(?:(?<!sh|ch|zh)(?<=h)uang|(?<!sh|ch|zh)(?<=h)ang|(?<!sh|ch|zh)(?<=h)eng|(?<!sh|ch|zh)(?<=h)ong|(?<!sh|ch|zh)(?<=h)uai|(?<!sh|ch|zh)(?<=h)uan|(?<!sh|ch|zh)(?<=h)ai|(?<!sh|ch|zh)(?<=h)an|(?<!sh|ch|zh)(?<=h)ao|(?<!sh|ch|zh)(?<=h)ei|(?<!sh|ch|zh)(?<=h)en|(?<!sh|ch|zh)(?<=h)ou|(?<!sh|ch|zh)(?<=h)ua|(?<!sh|ch|zh)(?<=h)ui|(?<!sh|ch|zh)(?<=h)un|(?<!sh|ch|zh)(?<=h)uo|(?<!sh|ch|zh)(?<=h)a|(?<!sh|ch|zh)(?<=h)e|(?<!sh|ch|zh)(?<=h)u)|(?:(?<=k)uang|(?<=k)ang|(?<=k)eng|(?<=k)ong|(?<=k)uai|(?<=k)uan|(?<=k)ai|(?<=k)an|(?<=k)ao|(?<=k)en|(?<=k)ou|(?<=k)ua|(?<=k)ui|(?<=k)un|(?<=k)uo|(?<=k)a|(?<=k)e|(?<=k)u)|(?:(?<=j)iang|(?<=j)iong|(?<=j)ian|(?<=j)iao|(?<=j)ing|(?<=j)üan|(?<=j)ia|(?<=j)ie|(?<=j)in|(?<=j)iu|(?<=j)üe|(?<=j)ün|(?<=j)i|(?<=j)ü)|(?:(?<=m)ang|(?<=m)eng|(?<=m)ian|(?<=m)iao|(?<=m)ing|(?<=m)ai|(?<=m)an|(?<=m)ao|(?<=m)ei|(?<=m)en|(?<=m)ie|(?<=m)in|(?<=m)iu|(?<=m)ou|(?<=m)a|(?<=m)e|(?<=m)i|(?<=m)o|(?<=m)u)|(?:(?<=l)iang|(?<=l)ang|(?<=l)eng|(?<=l)ian|(?<=l)iao|(?<=l)ing|(?<=l)ong|(?<=l)uan|(?<=l)ai|(?<=l)an|(?<=l)ao|(?<=l)ei|(?<=l)ia|(?<=l)ie|(?<=l)in|(?<=l)iu|(?<=l)ou|(?<=l)un|(?<=l)uo|(?<=l)üe|(?<=l)a|(?<=l)e|(?<=l)i|(?<=l)o|(?<=l)u|(?<=l)ü)|(?:(?<=n)iang|(?<=n)ang|(?<=n)eng|(?<=n)ian|(?<=n)iao|(?<=n)ing|(?<=n)ong|(?<=n)uan|(?<=n)ai|(?<=n)an|(?<=n)ao|(?<=n)ei|(?<=n)en|(?<=n)ie|(?<=n)in|(?<=n)iu|(?<=n)ou|(?<=n)un|(?<=n)uo|(?<=n)üe|(?<=n)a|(?<=n)e|(?<=n)i|(?<=n)u|(?<=n)ü)|(?:(?<=q)iang|(?<=q)iong|(?<=q)ian|(?<=q)iao|(?<=q)ing|(?<=q)üan|(?<=q)ia|(?<=q)ie|(?<=q)in|(?<=q)iu|(?<=q)üe|(?<=q)ün|(?<=q)i|(?<=q)ü)|(?:(?<=p)ang|(?<=p)eng|(?<=p)ian|(?<=p)iao|(?<=p)ing|(?<=p)ai|(?<=p)an|(?<=p)ao|(?<=p)ei|(?<=p)en|(?<=p)ie|(?<=p)in|(?<=p)ou|(?<=p)a|(?<=p)i|(?<=p)o|(?<=p)u)|(?:(?<=s)ang|(?<=s)eng|(?<=s)ong|(?<=s)uan|(?<=s)ai|(?<=s)an|(?<=s)ao|(?<=s)en|(?<=s)ou|(?<=s)ui|(?<=s)un|(?<=s)uo|(?<=s)a|(?<=s)e|(?<=s)i|(?<=s)u)|(?:(?<=r)ang|(?<=r)eng|(?<=r)ong|(?<=r)uan|(?<=r)an|(?<=r)ao|(?<=r)en|(?<=r)ou|(?<=r)ua|(?<=r)ui|(?<=r)un|(?<=r)uo|(?<=r)e|(?<=r)i|(?<=r)u)|(?:(?<=t)ang|(?<=t)eng|(?<=t)ian|(?<=t)iao|(?<=t)ing|(?<=t)ong|(?<=t)uan|(?<=t)ai|(?<=t)an|(?<=t)ao|(?<=t)ei|(?<=t)ie|(?<=t)ou|(?<=t)ui|(?<=t)un|(?<=t)uo|(?<=t)a|(?<=t)e|(?<=t)i|(?<=t)u)|(?:(?<=w)ang|(?<=w)eng|(?<=w)ai|(?<=w)an|(?<=w)ei|(?<=w)en|(?<=w)a|(?<=w)o|(?<=w)u)|(?:(?<=y)ang|(?<=y)ing|(?<=y)ong|(?<=y)uan|(?<=y)ai|(?<=y)an|(?<=y)ao|(?<=y)in|(?<=y)ou|(?<=y)ue|(?<=y)un|(?<=y)a|(?<=y)e|(?<=y)e|(?<=y)i|(?<=y)o|(?<=y)u)|(?:(?<=x)iang|(?<=x)iong|(?<=x)ian|(?<=x)iao|(?<=x)ing|(?<=x)üan|(?<=x)ia|(?<=x)ie|(?<=x)in|(?<=x)iu|(?<=x)üe|(?<=x)ün|(?<=x)i|(?<=x)ü)|(?:(?<=z)ang|(?<=z)eng|(?<=z)ong|(?<=z)uan|(?<=z)ai|(?<=z)an|(?<=z)ao|(?<=z)ei|(?<=z)en|(?<=z)ou|(?<=z)ui|(?<=z)un|(?<=z)uo|(?<=z)a|(?<=z)e|(?<=z)i|(?<=z)u)|(?:(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)a|(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)ai|(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)an|(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)ang|(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)ao|(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)e|(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)ei|(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)en|(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)eng|(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)er|(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)o|(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)ou))$

Answer 1

假设您的正则表达式引擎支持后视、原子组和所有格量词（即 PCRE 功能）：

可以替换的一些示例：

• 全部(?:由(?>

• 开始（所有第一个命名的组）：

  ^(?P<initial>(?>[csz]h?+|[bdfghj-npqrtwxy])?)

• 这部分*由：

  |(?<![csz]h)(?<=h)(?>a(?>[io]|ng?+)?|e(?>i|ng?+)?|o(?>u|ng)|u(?>[ino]|a(?>i|ng?+)?)?)

*（即|(?:(?<!sh|ch|zh)(?<=h)uang|(?<!sh|ch|...|(?<!sh|ch|zh)(?<=h)u)：）

• 最后一部分* 作者：

  |(?<![bcdfghj-np-tw-z])(?>a(?>[io]|ng?+)?|e(?>[ir]|ng?+)?|ou?+))$

*（即|(?:(?<!r|c|b|d|g|f|h|k|j|m|l|n|q|p|s|t|w|y|x|z)a|(?<!r|c|b|d|...))$：）

其他部分如何处理：

例子：

(?:(?<=ch)uang|(?<=ch)ang|(?<=ch)eng|(?<=ch)ong|(?<=ch)uai|(?<=ch)uan|(?<=ch)ai|(?<=ch)an|(?<=ch)ao|(?<=ch)en|(?<=ch)ou|(?<=ch)ua|(?<=ch)ui|(?<=ch)un|(?<=ch)uo|(?<=ch)a|(?<=ch)e|(?<=ch)i|(?<=ch)u)

_ 所有此类零件的后视功能相同，您必须为每个零件执行这些步骤 _

# step 1: lookarounds factorization

(?<=ch)(?>ang|eng|ong|uai|uan|ai|an|ao|en|ou|ua|ui|un|uo|a|e|i|u)

# step 2: sort all the content by alphabetic order 

(?<=ch)(?>a|ai|an|ang|ao|e|en|eng|i|ong|ou|u|ua|uai|uan|ui|un|uo)

# step 3: group by first letter: don't forget the ? if the letter can be alone

(?<=ch)(?>a(?>i|n|ng|o)?|e(?>n|ng)?|i|o(?>ng|u)|u(?>a|ai|an|i|n|o)?)

# step 4: reduce the terminations (ie: n & ng => ng?+) 

(?<=ch)(?>a(?>i|ng?+|o)?|e(?>ng?+)?|i|o(?>ng|u)|u(?>a[in]?+|i|n|o)?)

# step 5: put single letters in a character class

(?<=ch)(?>a(?>[io]|ng?+)?|e(?>ng?+)?|i|o(?>ng|u)|u(?>a[in]?+|[ino])?)

结论

虽然结果更短，但这里的目标是优化。我使用原子组和所有格量词减少了分解测试的数量和回溯的数量。

一些限制

请注意，并非所有正则表达式都支持诸如原子组和所有格量词之类的正则表达式功能，但可以解决该问题：

• 对于不支持所有格量​​词的风味：更改?+为?
• 对于不支持原子组的风味：更改(?>为(?:

（请注意，在 Python 中使用原子组有一个技巧，您可以使用计时器对其进行测试，以包围所有模式。请参阅这篇令人难以置信的帖子：Python 正则表达式是否与 Ruby 的原子分组等效？）

一些正则表达式引擎（例如 javascript）不支持后向查找。在这种情况下，您必须只使用交替（即|）重写所有模式，这不是一件坏事，因为后视会使您的模式变慢；并放弃也不支持的命名捕获。（在这种情况下，应该注意，要删除负面的后视，您需要将这些部分中描述的音节放在所有其他部分之前，以便它们首先匹配。）

其他优化方式

• 重写你的模式，|而不是向后看
• 按最常用的音节对不同的行进行排序