问题
I came across some regular expressions that contain [^\\p{L}]. I understand that this is using some form of a Unicode category, but when I checked the documentation, I found only the following "L" categories:
Lu Uppercase letter UPPERCASE_LETTER
Ll Lowercase letter LOWERCASE_LETTER
Lt Titlecase letter TITLECASE_LETTER
Lm Modifier letter MODIFIER_LETTER
Lo Other letter OTHER_LETTER
What is L in this context?
回答1:
Taken from this link: http://www.regular-expressions.info/unicode.html
Check the Unicode Character Properties section.
\p{L} matches a single code point in the category "letter". If your input string is à encoded as U+0061 U+0300, it matches a without the accent. If the input is à encoded as U+00E0, it matches à with the accent. The reason is that both the code points U+0061 (a) and U+00E0 (à) are in the category "letter", while U+0300 is in the category "mark".
回答2:
I don't see any explicit mention of it, but an example on this page indicates that \\p{L} means any letter:
Categories may be specified with the optional prefix Is: Both \p{L} and \p{IsL} denote the category of Unicode letters.
来源：https://stackoverflow.com/questions/5969440/what-is-the-l-unicode-category