isAlpha :: Char → Bool
Selects alphabetic Unicode characters (lower-case, upper-case and title-case letters, plus letters of caseless scripts and modifiers letters).
But when I test,it can parse non-alphabetic characters like Chinese.
isAlpha '你'
True
For my understanding,alphabetic characters is specified to the language which are Alphabetic Writing System,but Chinese is Logographic Writing System.Is the alphabetic means the characters which belong to a language having registered in the Unicode Standard?
I think the documentation here needs some work - this function checks if something is a “letter”, and these use of the word “alphabetic” is somewhere between slightly unhelpful and outright incorrect. In colloquial English, it’s not uncommon to refer to a writing system as an alphabet, even if it’s not actually an alphabet, which is probably why this isn’t considered incorrect.
The important part of the documentation is the bit in parentheses, although it does require some familiarity with unicode to recognise what it is saying.
These are the unicode general character classes Ll, Lu, Lt, Lo and Lm (in that order). “你” belongs to the Lo class, which is why isAlpha '你' is true.
