Add lang-tag based task selection (lang-separation)

[andreaskoepf]

• ConversationMessage, TextReplyToMessage and TaskRequest now have lang property, if no value is provided 'en' is assumed
• POST api/v1/tasks/availability endpoint has a lang param
• default for lang column of message table is now 'en' (was 'en-US')
• task selection in TreeManager is language-dependent

[yk]

really cool, thank you.
It may be worth to think about always considering a set of languages, instead of only one, i.e. a user could ask for a task in either of their languages, and a task could be appropriate for either of two languages (i.e. translate from one to the other, or some math quiz, etc.).

but up to you

[andreaskoepf]

It may be worth to think about always considering a set of languages, instead of only one, i.e. a user could ask for a task in either of their languages, and a task could be appropriate for either of two languages (i.e. translate from one to the other, or some math quiz, etc.).

For task selection that is a future option. For submission of the message I would suggest to use only a single language tag(even when multiple languages are mixed). When the uses has more than one active language it would be necessary to specify the language used for a submission ... or to use the task's language as default.

Translation is a use-case, but a special one that won't even be solved by using a list of languages, e.g. like instruction: "Translate this text into Chinese: ..." .. while the instruction-message would be in "en" the task could only be fulfilled by users with "en" + "zh-cn" or similar, so somehow the user would need to specify the desired language of the reply.

I think we should first try the simple solution of 'single language set per session" which will be an improvement for 95% of all use-cases.

[yk]

sounds good

[andreaskoepf]

link #854