'-' and '_' may be treated in plain letters.

[yangbongsoo]

#193 becaue of _ char, order string find it in ENTITY_TRIE and replace ℴ
I think - and _ may be treated in plain letters.
Please tell me if you think I'm wrong or if I lack a test.

[mikesamuel]

Hmm. Since this was initially written, https://html.spec.whatwg.org/#named-character-references clarified which named character references are allowed without a trailing semicolon.

I believe, according to html.spec.whatwg, that &curren is allowed without a semicolon because there are two entries in that table, one of which does not have a trailing ;:

Name	Character	Glyph
curren;	U+000A4	¤
curren	U+000A4	¤

Maybe we should just derive a list of HTML entities that are allowed without semicolons instead of looking for extra letters.

[mikesamuel]

Does #201 do what you need?

[yangbongsoo]

yes. I close this PR.