I use lualatex, but I believe this would apply to any *tex. I will narrow the question to Latin-based languages, so that we do not have to deal with special initial/final forms, required ligatures, and so forth. This is for text (not math) in any general document class.
Commands \lefthyphenmin
and \righthyphenmin
accept an integer number, which is the minimum number of characters at the end/beginning of a line, when a word is hyphenated. Packages babel
and polyglossia
load default settings for each chosen language. The user may manually change the values.
Now to my question: Do the hyphenation rules disregard any punctuation (or other non-letter symbol) that is attached to a word? Example: scarequotes
versus “scarequotes”
used mid-sentence. Assuming that hyphenation is allowed, I would expect both to hyphenate the same (or not), even though one word has curly quotes attached, and the other does not. In other words, I would not expect the quotes to count against the hyphenmins.
I could experiment with random text, but perhaps this is something generally known? Especially in French, with its added punctuation spacing, would it be different?
EDIT (in light of comments): If the language regards something as a letter, then I intend it to be a letter, in this context. For example, the English word wouldn't
regards the apostrophe as a letter (I hope). I expect that in languages that use apostrphe, or something similar, at the beginning or end of words, it would be a letter.
Best Answer
Your hunch is correct: TeX's hyphenation rules apply to words, whether or not they're preceded or followed by quotation marks and/or punctuation marks.