comparison mercurial/templater.py @ 36509:638c012a87ef

templater: add option to parse template string just like raw string literal

This seems a bit odd because the template syntax has no raw string literal
containing template fragments, but is necessary to port filename format string
to templater. See the next patch.

36508:d7a23d6184a2

            return parsed, pos
        else:
            raise error.ProgrammingError('unexpected type: %s' % typ)
    raise error.ProgrammingError('unterminated scanning of template')

def scantemplate(tmpl):
    """Scan (type, start, end) positions of outermost elements in template

    >>> list(scantemplate(b'foo{bar}"baz'))
    [('string', 0, 3), ('template', 3, 8), ('string', 8, 12)]
    >>> list(scantemplate(b'outer{"inner"}outer'))
    [('string', 0, 5), ('template', 5, 14), ('string', 14, 19)]
    >>> list(scantemplate(b'foo\\{escaped}'))
    [('string', 0, 5), ('string', 5, 13)]
    """
    last = None
    for typ, val, pos in _scantemplate(tmpl, 0, len(tmpl)):
        if last:
            yield last + (pos,)
        if typ == 'end':
            return
        else:
            last = (typ, pos)
    raise error.ProgrammingError('unterminated scanning of template')

def _scantemplate(tmpl, start, stop, quote=''):
    """Parse template string into chunks of strings and template expressions"""
    sepchars = '{' + quote
    pos = start
    p = parser.parser(elements)
    while pos < stop:
        n = min((tmpl.find(c, pos, stop) for c in sepchars),
                key=lambda n: (n < 0, n))
        if n < 0:
            yield ('string', parser.unescapestr(tmpl[pos:stop]), pos)
            pos = stop
            break
        c = tmpl[n:n + 1]
        bs = (n - pos) - len(tmpl[pos:n].rstrip('\\'))
        if bs % 2 == 1:
            # escaped (e.g. '\{', '\\\{', but not '\\{')
            yield ('string', parser.unescapestr(tmpl[pos:n - 1]) + c, pos)
            pos = n + 1
            continue
        if n > pos:
            yield ('string', parser.unescapestr(tmpl[pos:n]), pos)
        if c == quote:
            yield ('end', None, n + 1)
            return

        parseres, pos = p.parse(tokenize(tmpl, n + 1, stop, '}'))

36509:638c012a87ef

            return parsed, pos
        else:
            raise error.ProgrammingError('unexpected type: %s' % typ)
    raise error.ProgrammingError('unterminated scanning of template')

def scantemplate(tmpl, raw=False):
    r"""Scan (type, start, end) positions of outermost elements in template

    If raw=True, a backslash is not taken as an escape character just like
    r'' string in Python. Note that this is different from r'' literal in
    template in that no template fragment can appear in r'', e.g. r'{foo}'
    is a literal '{foo}', but ('{foo}', raw=True) is a template expression
    'foo'.

    >>> list(scantemplate(b'foo{bar}"baz'))
    [('string', 0, 3), ('template', 3, 8), ('string', 8, 12)]
    >>> list(scantemplate(b'outer{"inner"}outer'))
    [('string', 0, 5), ('template', 5, 14), ('string', 14, 19)]
    >>> list(scantemplate(b'foo\\{escaped}'))
    [('string', 0, 5), ('string', 5, 13)]
    >>> list(scantemplate(b'foo\\{escaped}', raw=True))
    [('string', 0, 4), ('template', 4, 13)]
    """
    last = None
    for typ, val, pos in _scantemplate(tmpl, 0, len(tmpl), raw=raw):
        if last:
            yield last + (pos,)
        if typ == 'end':
            return
        else:
            last = (typ, pos)
    raise error.ProgrammingError('unterminated scanning of template')

def _scantemplate(tmpl, start, stop, quote='', raw=False):
    """Parse template string into chunks of strings and template expressions"""
    sepchars = '{' + quote
    unescape = [parser.unescapestr, pycompat.identity][raw]
    pos = start
    p = parser.parser(elements)
    while pos < stop:
        n = min((tmpl.find(c, pos, stop) for c in sepchars),
                key=lambda n: (n < 0, n))
        if n < 0:
            yield ('string', unescape(tmpl[pos:stop]), pos)
            pos = stop
            break
        c = tmpl[n:n + 1]
        bs = 0  # count leading backslashes
        if not raw:
            bs = (n - pos) - len(tmpl[pos:n].rstrip('\\'))
        if bs % 2 == 1:
            # escaped (e.g. '\{', '\\\{', but not '\\{')
            yield ('string', unescape(tmpl[pos:n - 1]) + c, pos)
            pos = n + 1
            continue
        if n > pos:
            yield ('string', unescape(tmpl[pos:n]), pos)
        if c == quote:
            yield ('end', None, n + 1)
            return

        parseres, pos = p.parse(tokenize(tmpl, n + 1, stop, '}'))