README: Add new language development instruction

[Tony763]

Hello, could somebody add list of necessary steps needed to begin with development of new language?

I did like to start with Czech language translation, but I miss steps for setting testing environment.
Something like:

1. Install Mycroft from source
2. Clone this repository to "location"
3. Install requirements by running python3 setup.py install
4. In "source" add code of your language to set is as supported.
5. Copy these files and append language code to end.
6. Do translations/changes and test them by ...

[ChanceNCounter]

First of all, thank you and WELCOME! This repo can use all the love it can get from folks who are willing to help localize its modules.

I'm currently working on a refactor that will make it much, much easier to add new languages and localize existing functions. This is a WIP, but, if other collaborators agree to it, it should hopefully be merged within the next little while.

In the meantime - and this is the impetus for the refactor - you've got to do the following:

1. Add corresponding test files in the lingua_franca/test/ directory (you'd have to do that anyway) and test them using pytest. I use VSCode, and I've got an extension for that. Similar extensions exist for other development environments. Also, when you do a PR here, CI will run tests, but it's good to test your own code before pushing.

2. Note that the current top level functions have giant if/elif statements to call the localized functions (this is the main thing I wanna fix.) Add all your functions to those if/elif statements. These are the ones in format.py and parse.py that you actually call.

3. Make sure your function signatures have all the arguments in the right order. You can skip trailing arguments you won't use. This, too, will hopefully be fixed, so that you can skip any names you won't use.

4. If you name all your arguments the same as they're named in the English functions - lang/parse_en.py and lang/format_en.py - that will help with the localization. Not mandatory, it'd just be very, very nice of you.

I can't promise what I'm doing will be merged. It's a big change. However, if the thing is merged, all you'll have to do is name your files and function signatures correctly. So, if you want to start now and wait a little while to see if the structure gets simplified, you can work on your functions in isolation and call them directly.

There's a languages channel at Mycroft chat here if you want some guidance as you go. Most of the people who contribute to this repo hang out in that channel.

Lastly, everything I ever say can be overruled by a person with 'Mycroft' in their handle ;)

[krisgesling]

Hey Tony,

Wanted to add that Lingua Franca is installed by default when you install Mycroft-core but for development you generally have this repo cloned elsewhere on your computer. You can use your changes in Mycroft by installing it in the Mycroft virtual environment.

If you added the Mycroft helper commands during setup you can just use:

mycroft-pip install /path/to/your/lingua-franca

Otherwise you need to:

cd ~/mycroft-core
source venv-activate.sh
pip install /path/to/your/lingua-franca

[Tony763]

@ChanceNCounter : Which pytest plugin you are using?

[ChanceNCounter]

The third one. It gets its own tab in the editor.

[Tony763]

Step two is translate all basic skills downloaded to /opt/mycroft/skill aka mycroft-skills? Or there is something else?

[krisgesling]

Lingua Franca is actually one of ~5 pieces needed to use Mycroft properly in another language. You can read more about all of those here:
https://mycroft-ai.gitbook.io/docs/using-mycroft-ai/customizations/languages

The Skills translations are all managed at https://translate.mycroft.ai/ which are then pushed back to each Skills repository. However you can also edit anything locally on your machine at the directory you mentioned, though it's important to note that if you edit a Skill locally it will stop receiving updates as any remote update would overwrite the changes you've made locally.

[JarbasAl]

this has been fixed in latest release

thank you once again @ChanceNCounter