translations MVP

[ogoffart]

This allow to translate a Slint interface using a @tr(".....") expression

TODO

• plurals in @tr()
• context in @tr() to disambiguate
• polish string extraction and tooling
• Example with translations in rust code
• Example with translations in C++ code

[tronical]

Wonderful start! A few brief comments. Let me know when you'd like get detailed reviews.

[medhefgo]

Just pitching in here to mention that gettext should not be forced/the only option. Fluent is considered to be better in many aspects and should be supported too.

[ogoffart]

@medhefgo totally, we don't want to force gettext.
That said, fluent is using messages IDs rather than the actual text as idea, which is incompatible with the vision we have.

[medhefgo]

Well, you can use message IDs in gettext too...
The more interesting difference is that fluent does the argument formatting itself (and afaiks has no positional args) and that plurals are fetched from the same function as singular messages.

Considering that, I guess it would be better to expose fluent as a separate function/macro (flt or so). And maybe gettext should be exposed as an explicit function/macro instead of a generic one (gtxt maybe, if it really has to be short names?). QML can get away with tr because it's the NIH translation system from Qt if I remember correctly.

[ogoffart]

Merging this right now even if it is not 100% complete yet since we can buid on top for before the next release.

( @medhefgo : more discussion about fluent in #33 if you're interested )