mwparserfromhell/mwparserfromhell/parser/contexts.py

# -*- coding: utf-8  -*-
#
# Copyright (C) 2012 Ben Kurtovic <ben.kurtovic@verizon.net>
#
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# of this software and associated documentation files (the "Software"), to deal
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# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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# SOFTWARE.

"""
This module contains various "context" definitions, which are essentially flags
set during the tokenization process, either on the current parse stack (local
contexts) or affecting all stacks (global contexts). They represent the context
the tokenizer is in, such as inside a template's name definition, or inside a
level-two heading. This is used to determine what tokens are valid at the
current point and also if the current parsing route is invalid.

The tokenizer stores context as an integer, with these definitions bitwise OR'd
to set them, AND'd to check if they're set, and XOR'd to unset them. The
advantage of this is that contexts can have sub-contexts (as ``FOO == 0b11``
will cover ``BAR == 0b10`` and ``BAZ == 0b01``).

Local (stack-specific) contexts:

* :py:const:`TEMPLATE`

    * :py:const:`TEMPLATE_NAME`
    * :py:const:`TEMPLATE_PARAM_KEY`
    * :py:const:`TEMPLATE_PARAM_VALUE`

* :py:const:`ARGUMENT`

    * :py:const:`ARGUMENT_NAME`
    * :py:const:`ARGUMENT_DEFAULT`

* :py:const:`WIKILINK`

    * :py:const:`WIKILINK_TITLE`
    * :py:const:`WIKILINK_TEXT`

* :py:const:`HEADING`

    * :py:const:`HEADING_LEVEL_1`
    * :py:const:`HEADING_LEVEL_2`
    * :py:const:`HEADING_LEVEL_3`
    * :py:const:`HEADING_LEVEL_4`
    * :py:const:`HEADING_LEVEL_5`
    * :py:const:`HEADING_LEVEL_6`

* :py:const:`COMMENT`

* :py:const:`TAG`

    * :py:const:`TAG_OPEN`

        * :py:const:`TAG_OPEN_NAME`
        * :py:const:`TAG_OPEN_ATTR`

            * :py:const:`TAG_OPEN_ATTR_NAME`
            * :py:const:`TAG_OPEN_ATTR_BODY`
            * :py:const:`TAG_OPEN_ATTR_QUOTED`
            * :py:const:`TAG_OPEN_ATTR_IGNORE`

    * :py:const:`TAG_BODY`
    * :py:const:`TAG_CLOSE`

Global contexts:

* :py:const:`GL_HEADING`
"""

# Local contexts:

TEMPLATE =             0b000000000000000000111
TEMPLATE_NAME =        0b000000000000000000001
TEMPLATE_PARAM_KEY =   0b000000000000000000010
TEMPLATE_PARAM_VALUE = 0b000000000000000000100

ARGUMENT =             0b000000000000000011000
ARGUMENT_NAME =        0b000000000000000001000
ARGUMENT_DEFAULT =     0b000000000000000010000

WIKILINK =             0b000000000000001100000
WIKILINK_TITLE =       0b000000000000000100000
WIKILINK_TEXT =        0b000000000000001000000

HEADING =              0b000000001111110000000
HEADING_LEVEL_1 =      0b000000000000010000000
HEADING_LEVEL_2 =      0b000000000000100000000
HEADING_LEVEL_3 =      0b000000000001000000000
HEADING_LEVEL_4 =      0b000000000010000000000
HEADING_LEVEL_5 =      0b000000000100000000000
HEADING_LEVEL_6 =      0b000000001000000000000

COMMENT =              0b000000010000000000000

TAG =                  0b111111100000000000000
TAG_OPEN =             0b001111100000000000000
TAG_OPEN_NAME =        0b000000100000000000000
TAG_OPEN_ATTR =        0b001111000000000000000
TAG_OPEN_ATTR_NAME =   0b000001000000000000000
TAG_OPEN_ATTR_BODY =   0b000010000000000000000
TAG_OPEN_ATTR_QUOTED = 0b000100000000000000000
TAG_OPEN_ATTR_IGNORE = 0b001000000000000000000
TAG_BODY =             0b010000000000000000000
TAG_CLOSE =            0b100000000000000000000


# Global contexts:

GL_HEADING = 0b1