[icu-design] need stronger form of MessageFormat.autoQuoteApostrophe()

[Markus S. <mar...@gm...>]

Dear ICU team & users,

I am looking at using MessageFormat, and the well-known issue of dealing
with the single quote=apostrophe.

We have MessageFormat.autoQuoteApostrophe() which will "do the right thing"
in some cases. For example, it turns "I don't know {0}" into "I don''t know
{0}".

However, it does not modify any text inside {curly braces}. This is
inconvenient, because inside braces we find not just syntax (e.g.,
number/date/time patterns) but also translatable text in
choice/plural/select patterns. For
example, MessageFormat.autoQuoteApostrophe() does not modify "{0, select,
female {I don't know her} other {I don't know him}}" at all, resulting in a
pattern parse error.

I hesitate to just redefine and change MessageFormat.autoQuoteApostrophe().
I guess I should look at writing another version of it that deals with all
apostrophes, including ones inside {braces}.
(autoQuoteApostrophesAlsoNested()? autoQuoteApostrophe(String, enum
QuotingStyle)?)

*Question:* Why does MessageFormat.autoQuoteApostrophe() only handle
top-level apostrophes? Is it so that embedded NumberFormat or DateFormat
patterns can use single apostrophes? Does the MessageFormat parser not quote
literals inside arguments?

Thanks,
markus