Crate is_vowel

Test for vowels in Romance languages.

Deciding whether some grapheme is a “vowel” (represents a “vowel sound”) is language dependent, and the author is not aware of any standardization efforts for vowel identification.

Even for the Romance languages, the situation is a bit complicated. The basic Romance vowels are “a”, “e”, “i”, “o”, “u”. However, for example:

• Uppercase versions are also vowels.
• Accented versions are also vowels.
• “Sometimes ‘y’, sometimes ‘w’.” These letters are consonant in some situations, vowels in others.

This code attempts to provide reasonable heuristic answers as to the Romance-language-“vowelness” of a Unicode codepoint.

No attempt is made here to deal with non-Romance languages, even though some non-Romance vowel letters are borrowed in Romance languages: for example, “æ” and “Æ” are used in some British English. It would be great to use vowel letter tables for a variety of languages, but so far the author has been unable to locate such tables (surprisingly).

Traits

IsRomanceVowel