# -*- coding: utf-8 -*-
#
# This file is part of the parce Python package.
#
# Copyright © 2019-2020 by Wilbert Berendsen <info@wilbertberendsen.nl>
#
# This module is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This module is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
"""
Parse various troff dialects, most notably groff.
https://www.gnu.org/software/groff/
"""
__all__ = ('Troff',)
import re
from parce import Language, lexicon, skip, default_action, default_target
from parce.action import (
Comment, Delimiter, Name, Number, Operator, String, Text)
from parce.rule import bygroup
[docs]class Troff(Language):
@lexicon(re_flags=re.MULTILINE)
def root(cls):
yield r"^(['.])[ \t]*", bygroup(Delimiter.Request), cls.request, cls.name
yield from cls.escapes()
yield default_action, Text
@lexicon(re_flags=re.MULTILINE)
def request(cls):
yield from cls.escapes()
yield r'\n', skip, -1
yield r' (")', bygroup(String), cls.string
yield r'([-+]?(?:\d+(?:\.\d*)?)|\.\d+)([ciPpmMnuvsf])?', bygroup(Number, Name.Unit)
yield r'[-+*/%=<>&:!()]|[=<>]=', Operator
yield r'[<>]\?|;', Operator # GNU extension
yield default_action, Text
@lexicon
def name(cls):
"""The name of a request, handle some special preprocessor macros."""
yield r'lilypond\b', Name.Identifier.Preprocessed, -1, cls.preprocess_lilypond
yield r'[^\W\d]\w*\b', Name.Identifier, -1
yield default_target, -1
@lexicon(re_flags=re.MULTILINE)
def string(cls):
"""String in request arguments."""
yield r'$', None, -1
yield r'"', String, -1
yield from cls.escapes(String)
yield default_action, String
@lexicon(re_flags=re.MULTILINE)
def comment(cls):
yield r'$', None, -1
yield from cls.comment_common()
@lexicon
def preprocess_lilypond(cls):
"""If "start" is found, go to LilyPond, otherwise back to the request context."""
yield r'[ \t]*(start)\b', bygroup(Name.Command), -2, cls.lilypond, cls.request
yield default_target, -1 # back to request
@lexicon(re_flags=re.MULTILINE)
def lilypond(cls):
"""Stuff between .lilypond start and .lilypond end."""
from .lilypond import LilyPond
yield r"^(['.])[ \t]*(lilypond) +(end)\b", \
bygroup(Delimiter.Request, Name.Identifier.Preprocessed, Name.Command), \
-1
yield from LilyPond.root
[docs] @classmethod
def escapes(cls, escape_base=Text):
# escapes (man 7 groff)
yield r'\\["#]', Comment, cls.comment
# prevent interpreting request after continuation line
yield r"(\\\n)([.'])?", bygroup(escape_base.Escape, Text)
# single char escapes
yield r"\\[\\'`_.%! 0|^&)/,~:{}acdeEprtu-]", escape_base.Escape
# escapes expecting single, two-char or bracketed arg
yield r"\\[\*$fFgkmMnVY](?:\[[^\]\n]*\]|\(..|.)", escape_base.Escape
# \s
yield r"\\s[-+]?(?:\d|\([-+]?\d\d|\[[\d+-]+\]|'[\d+-]+')", escape_base.Escape
# escapes expecting a single-quoted argument
yield r"\\[AbBCDlLnoRsSvwxXZ](?:'[^'\n]*')?", escape_base.Escape
# \(<xx> or \[<xxxx>]
yield r"\\(?:\[[^\]\n]*\]|\(..)", escape_base.Escape
# undefined (last resort)
yield r"\\", escape_base.Escape