Add support for the Logtalk language

[pmoura]

I noticed a single failed test, apparently due to use of a cell magic in the sample notebook. The cell magic is specific to the Logtalk kernel. Your help is most appreciated on how best to fix this test failure. Thanks.

========================================================================================================= FAILURES =========================================================================================================
_________________________________________________________________________________ test_ipynb_to_Rmd[ipynb_logtalk/logtalk_notebook.ipynb] __________________________________________________________________________________

ipynb_file = '/Users/pmoura/jupytext/tests/data/notebooks/inputs/ipynb_logtalk/logtalk_notebook.ipynb', no_jupytext_version_number = None

    def test_ipynb_to_Rmd(ipynb_file, no_jupytext_version_number):
>       assert_conversion_same_as_mirror(ipynb_file, "Rmd", "ipynb_to_Rmd")

/Users/pmoura/jupytext/tests/functional/round_trip/test_mirror.py:53: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
/Users/pmoura/jupytext/src/jupytext/compare.py:441: in assert_conversion_same_as_mirror
    compare(actual, expected)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

actual = "---\njupyter:\n  kernelspec:\n    display_name: Logtalk\n    language: logtalk\n    name: logtalk_kernel\n---\n\n# An...\n\n:- end_object.\n```\n\n## Sample query\n\n```{logtalk vscode={'languageId': 'logtalk'}}\nack::ack(2, 4, V).\n```\n"
expected = "---\njupyter:\n  kernelspec:\n    display_name: Logtalk\n    language: logtalk\n    name: logtalk_kernel\n---\n\n# An...\n\n:- end_object.\n```\n\n## Sample query\n\n```{logtalk vscode={'languageId': 'logtalk'}}\nack::ack(2, 4, V).\n```\n"
actual_name = 'actual', expected_name = 'expected', return_diff = False

    def compare(
        actual, expected, actual_name="actual", expected_name="expected", return_diff=False
    ):
        """Compare two strings, lists or dict-like objects"""
        if actual != expected:
            diff = difflib.unified_diff(
                _multilines(expected),
                _multilines(actual),
                expected_name,
                actual_name,
                lineterm="",
            )
            if expected_name == "" and actual_name == "":
                diff = list(diff)[2:]
            diff = "\n".join(diff)
            if return_diff:
                return diff
>           raise AssertionError("\n" + diff)
E           AssertionError: 
E           --- expected
E           +++ actual
E           @@ -9,7 +9,7 @@
E            # An implementation of the Ackermann function
E            
E            ```{logtalk vscode={'languageId': 'logtalk'}}
E           -%%load ack.lgt
E           +% %%load ack.lgt
E            
E            :- object(ack).

/Users/pmoura/jupytext/src/jupytext/compare.py:50: AssertionError
===================================================================================================== warnings summary =====================================================================================================
../../../usr/local/Caskroom/miniconda/base/envs/jupytext-dev/lib/python3.13/site-packages/sphinx_gallery/sphinx_compatibility.py:71
  /usr/local/Caskroom/miniconda/base/envs/jupytext-dev/lib/python3.13/site-packages/sphinx_gallery/sphinx_compatibility.py:71: RemovedInSphinx80Warning: The alias 'sphinx.util.status_iterator' is deprecated, use 'sphinx.util.display.status_iterator' instead. Check CHANGES for Sphinx API modifications.
    status_iterator = sphinx.util.status_iterator

tests/external/jupyter_fs/test_jupyter_fs.py::test_jupytext_jupyter_fs_metamanager
  /usr/local/Caskroom/miniconda/base/envs/jupytext-dev/lib/python3.13/site-packages/traitlets/traitlets.py:3615: DeprecationWarning: metadata {'per_key_traits': <traitlets.traitlets.Dict object at 0x11e3b60a0>} was set from the constructor. With traitlets 4.1, metadata should be set using the .tag() method, e.g., Int().tag(key1='value1', key2='value2')
    super().__init__(trait=trait, default_value=default_value, **kwargs)

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
================================================================================================= short test summary info ==================================================================================================
FAILED tests/functional/round_trip/test_mirror.py::test_ipynb_to_Rmd[ipynb_logtalk/logtalk_notebook.ipynb] - AssertionError: 
=========================================================================== 1 failed, 3129 passed, 161 skipped, 2 warnings in 187.05s (0:03:07) ============================================================================

[github-actions]

Thank you for making this pull request.

Did you know? You can try it on Binder: or .

Also, the version of Jupytext developed in this PR can be installed with pip:

HATCH_BUILD_HOOKS_ENABLE=true pip install git+https://github.com/pmoura/jupytext.git@add_logtalk_language_support

(this requires nodejs, see more at Developing Jupytext)

[pmoura]

Doing further testing, notice that conversions to hydrogen and rmd are incorrect when cell magic is present (e.g., %%load). Opening the file as a notebook strips the first % from cell magic, breaking it.

[mwouts]

Hello @pmoura , sorry for the long delay in responding. I expect to be more responsive from now on. Many thanks for your PR, that is very helpful! I will have a look to the failing test and comment back.

[pmoura]

Btw, I converted the Markdown documentation of all Logtalk distribution examples (~200) so that Jupytext can open the files as notebooks. I have been testing primarily using VSCode with this extension. Happy with the results. Thanks for your work on Jupytext!

[pmoura]

Should I also update the CHANGELOG.md file?

[mwouts]

Hey @pmoura , I've fixed the CI and will now give a look at the failing test.

What do you think of the second commit of #1310? Since the comment char is % in logtalk the magic commands are valid comments in logtalk script, aren't they?

[pmoura]

Hey @pmoura , I've fixed the CI and will now give a look at the failing test.

What do you think of the second commit of #1310? Since the comment char is % in logtalk the magic commands are valid comments in logtalk script, aren't they?

Indeed Logtalk (and Prolog) use the % character for line comments. In the Jupyter kernel for Logtalk, all line and cell magic thus start with this character and thus are valid comments in Logtalk.

Thanks for fixing this issue in my pull request. Looking forward to the 1.16.7 release!

[mwouts]

Merged through #1310 - thank you @pmoura !