Java: how to check if character belongs to a specific unicode block?

Question

I need to identify what natural language my input belongs to. The goal is to distinguish between Arabic and English words in a mixed input, where the input is Unicode and is extracted from XML text nodes. I have noticed the class Character.UnicodeBlock. Is it related to my problem? How can I get it to work?

Edit: The Character.UnicodeBlock approach was useful for Arabic, but apparently doesn't do it for English (or other European languages) because the BASIC_LATIN Unicode block covers symbols and non-printable characters as well as letters. So now I am using the matches() method of the String object with the regex expression "[A-Za-z]+" instead. I can live with it, but perhaps someone can suggest a nicer/faster way.

Answer 1

Yes, you can simply use Character.UnicodeBlock.of(char)

Answer 2

If [A-Za-z]+ meets your requirement, you aren't going to find anything faster or prettier. However, if you want to match all letters in the Latin1 block (including accented letters and ligatures), you can use this:

Pattern p = Pattern.compile("[\\pL&&\\p{L1}]+");

That's the intersection of the set of all Unicode letters and the set of all Latin1 characters.