get_cwl.py 文件源码

def get_longer(old, new):
    """Get the longer of two command sequences when one is a superset of
    the other. Otherwise, return a list containing both.
    """
    try:
        pngs = ('\\begin', '\\end')
        old_parts = {x for x in sep_RE.split(old) if x if x not in pngs}
        new_parts = {y for y in sep_RE.split(new) if y if y not in pngs}
        if new_parts == old_parts and new != old and any('\\begin' in c for c
                                                         in (old, new)):
            return old if old.startswith('\\begin') else new
        elif new_parts.issubset(old_parts):
            return old
        elif old_parts.issubset(new_parts):
            return new
        else:
            return [old, new]
    except TypeError:
        # XXX Verify this test is necessary; smells like spam.
        if not isinstance(old, abc.MutableSequence):
            raise TypeError
        # ``new`` must be returned from all combinations to get promoted.
        leaders = set()
        for sig in old:
            res = get_longer(sig, new)
            # Ensure 'foo' doesn't get split into ['f', 'o', 'o']
            winners = (set(res) if isinstance(res, abc.MutableSequence)
                       else set((res,)))
            sigs = (set(sig) if isinstance(sig, abc.MutableSequence) else
                    set((sig,)))
            # ``new`` is always just a string.
            losers = (sigs | set((new,))) - winners
            leaders |= winners
            leaders -= losers
        return sorted(leaders)
    return None