lyx_mirror/lib/lyx2lyx/unicode_symbols.py

# This file is part of lyx2lyx
# Copyright (C) 2011 The LyX team
#
# This program 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 2
# of the License, or (at your option) any later version.
#
# This program 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, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

"Import unicode_reps from this module for access to the unicode<->LaTeX mapping."

import codecs
import os
import re


def read_unicodesymbols():
    "Read the unicodesymbols list of unicode characters and corresponding commands."
    pathname = os.path.abspath(os.path.dirname(__file__))
    filename = os.path.join(pathname.strip("lyx2lyx"), "unicodesymbols")

    # Read as Unicode strings in both, Python 2 and 3
    # Specify the encoding for those systems where the default is not UTF-8
    fp = codecs.open(filename, encoding="utf8")

    # A backslash, followed by some non-word character, and then a character
    # in brackets. The idea is to check for constructs like: \"{u}, which is how
    # they are written in the unicodesymbols file; but they can also be written
    # as: \"u or even \" u.
    # The two backslashes in the string literal are needed to specify a literal
    # backslash in the regex. Without r prefix, these would be four backslashes.
    r = re.compile(r"\\(\W)\{(\w)\}")

    spec_chars = []
    for line in fp.readlines():
        if not line.strip() or line.startswith("#"):
            # skip empty lines and comments
            continue
        # Note: backslashes in the string literals with r prefix are not escaped,
        #       so one backslash in the source file equals one backslash in memory.
        #       Without r prefix backslahses are escaped, so two backslashes in the
        #       source file equal one backslash in memory.
        line = line.replace(' "', " ")  # remove all quotation marks with spaces before
        line = line.replace('" ', " ")  # remove all quotation marks with spaces after
        line = line.replace(r"\"", '"')  # unescape "
        line = line.replace(r"\\", "\\")  # unescape \
        try:
            [ucs4, command, dead] = line.split(None, 2)
            if command[0:1] != "\\":
                continue
            literal_char = chr(int(ucs4, 16))
            if (
                line.find("notermination=text") < 0
                and line.find("notermination=both") < 0
                and command[-1] != "}"
            ):
                command = command + "{}"
            spec_chars.append([command, literal_char])
        except:
            continue
        m = r.match(command)
        if m != None:
            command = "\\"
            commandbl = command
            command += m.group(1) + m.group(2)
            commandbl += m.group(1) + " " + m.group(2)
            spec_chars.append([command, literal_char])
            spec_chars.append([commandbl, literal_char])
    fp.close()
    return spec_chars


unicode_reps = read_unicodesymbols()