pandoc filter for the french

code-block-in-english.py

#!/usr/bin/env python3
"""
Convert the CodeBlock into english text. Very useful if the base language adds
some special magic rules which are altering the context. E.g. french puts a
space before the colon (:).

::
    $ pandoc \
        --filter ./code-block-in-english.py \
        ...

If the ``otherlangs`` properties is set, make sure it contains "en" already.

::
    lang: fr
    otherlangs: [en]
"""

from pandocfilters import (elt, toJSONFilter, Para, RawBlock, CodeBlock,  #noqa
                           RawInline, Code, Str)


# those are not present in pandocfilters.
MetaInlines = elt('MetaInlines', 1)
MetaList = elt('MetaList', 1)


def other(lang, full_lang):
    """
    Create a filter that changes the language before a CodeBlock or a RawBlock.
    """

    before = RawInline('tex',
                       r'\begin{{otherlanguage}}{{{0}}}'.format(full_lang))
    after = RawInline('tex', r'\end{otherlanguage}')

    def fn(key, value, format, meta):
        """The filter."""

        # Adds the otherlangs properties if not found.
        if 'otherlangs' not in meta:
            meta['otherlangs'] = MetaList([MetaInlines([Str(lang)])])

        if key in ('CodeBlock', 'RawBlock'):
            # Uses CodeBlock and RawBlock, hence the #noqa above.
            block = globals()[key](*value)
            return [Para([before]), block, Para([after])]
        if key == 'Code':
            return [before, Code(*value), after]

    return fn


if __name__ == "__main__":
    toJSONFilter(other('en', 'english'))