# -*- coding: utf-8 -*- # # The MIT License (MIT) # # Copyright (c) 2019 Philippe Faist # # Permission is hereby granted, free of charge, to any person obtaining a copy # of this software and associated documentation files (the "Software"), to deal # in the Software without restriction, including without limitation the rights # 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. # # 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 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN # THE SOFTWARE. # r""" Provides classes and helper functions to describe a LaTeX context of known macros and environments, specifying how they should be parsed by :py:mod:`pylatexenc.latexwalker`. .. versionadded:: 2.0 The entire module :py:mod:`pylatexenc.macrospec` was introduced in `pylatexenc 2.0`. """ import sys if sys.version_info.major > 2: # Py3 def unicode(s): return s _basestring = str _str_from_unicode = lambda x: x _unicode_from_str = lambda x: x else: # Py2 _basestring = basestring _str_from_unicode = lambda x: unicode(x).encode("utf-8") _unicode_from_str = lambda x: x.decode("utf-8") # ------------------------------------------------------------------------------ from ._argparsers import ( MacroStandardArgsParser, ParsedMacroArgs, ParsedVerbatimArgs, VerbatimArgsParser, ) # ------------------------------------------------------------------------------ class MacroSpec(object): r""" Stores the specification of a macro. This stores the macro name and instructions on how to parse the macro arguments. .. py:attribute:: macroname The name of the macro, without the leading backslash. .. py:attribute:: args_parser The parser instance that can understand this macro's arguments. For standard LaTeX macros this is usually a :py:class:`MacroStandardArgsParser` instance. If you specify a string, then for convenience this is interpreted as an argspec argument for :py:class:`MacroStandardArgsParser` and such an instance is automatically created. """ def __init__(self, macroname, args_parser=MacroStandardArgsParser(), **kwargs): super(MacroSpec, self).__init__(**kwargs) self.macroname = macroname if isinstance(args_parser, _basestring): self.args_parser = MacroStandardArgsParser(args_parser) else: self.args_parser = args_parser def parse_args(self, *args, **kwargs): r""" Shorthand for calling the :py:attr:`args_parser`\ 's `parse_args()` method. See :py:class:`MacroStandardArgsParser`. """ return self.args_parser.parse_args(*args, **kwargs) def __repr__(self): return "MacroSpec(macroname=%r, args_parser=%r)" % ( self.macroname, self.args_parser, ) class EnvironmentSpec(object): r""" Stores the specification of a LaTeX environment. This stores the environment name and instructions on how to parse any arguments provided after ``\begin{environment}``. .. py:attribute:: environmentname The name of the environment, i.e., the argument of ``\begin{...}`` and ``\end{...}``. .. py:attribute:: args_parser The parser instance that can understand this environment's arguments. For standard LaTeX environment this is usually a :py:class:`MacroStandardArgsParser` instance. If you specify a string, then for convenience this is interpreted as an argspec argument for :py:class:`MacroStandardArgsParser` and such an instance is automatically created. .. py:attribute:: is_math_mode A boolean that indicates whether or not the contents is to be interpreted in Math Mode. This would be True for environments like ``\begin{equation}``, ``\begin{align}``, etc., but False for ``\begin{figure}``, etc. .. note:: Starred variants of environments (as in ``\begin{equation*}``) must not be specified using an argspec as for macros (e.g., `argspec='*'`). Rather, we need to define a separate environment spec for the starred variant with the star in the name itself (``EnvironmentSpec('equation*', None)``) because the star really is part of the environment name. If you happened to use ``EnvironmentSpec('equation', '*')``, then the parser would recognize the expression ``\begin{equation}*`` but not ``\begin{equation*}``. """ def __init__( self, environmentname, args_parser=MacroStandardArgsParser(), is_math_mode=False, **kwargs ): super(EnvironmentSpec, self).__init__(**kwargs) self.environmentname = environmentname if isinstance(args_parser, _basestring): self.args_parser = MacroStandardArgsParser(args_parser) else: self.args_parser = args_parser self.is_math_mode = is_math_mode def parse_args(self, *args, **kwargs): r""" Shorthand for calling the :py:attr:`args_parser`\ 's `parse_args()` method. See :py:class:`MacroStandardArgsParser`. """ return self.args_parser.parse_args(*args, **kwargs) def __repr__(self): return ( "EnvironmentSpec(environmentname=%r, args_parser=%r, is_math_mode=%r)" % (self.environmentname, self.args_parser, self.is_math_mode) ) class SpecialsSpec(object): r""" Specification of a LaTeX "special char sequence": an active char, a ligature, or some other non-macro char sequence that has a special meaning. For instance, '&', '~', and '``' are considered as "specials". .. py:attribute:: specials_chars The string (one or several characters) that has a special meaning. E.g., '&', '~', '``', etc. .. py:attribute:: args_parser A parser (e.g. :py:class:`MacroStandardArgsParser`) that is invoked when the specials is encountered. Can/should be set to `None` if the specials should not parse any arguments (e.g. '~'). """ def __init__(self, specials_chars, args_parser=None, **kwargs): super(SpecialsSpec, self).__init__(**kwargs) self.specials_chars = specials_chars self.args_parser = args_parser def parse_args(self, *args, **kwargs): r""" Basically a shorthand for calling the :py:attr:`args_parser`\ 's `parse_args()` method. See :py:class:`MacroStandardArgsParser`. If however the py:attr:`args_parser` attribute is `None`, then this method returns `None`. """ if self.args_parser is None: return None return self.args_parser.parse_args(*args, **kwargs) def __repr__(self): return "SpecialsSpec(specials_chars=%r, args_parser=%r)" % ( self.specials_chars, self.args_parser, ) # ------------------------------------------------------------------------------ def std_macro(macname, *args, **kwargs): r""" Return a macro specification for the given macro. Syntax:: spec = std_macro(macname, argspec) # or spec = std_macro(macname, optarg, numargs) # or spec = std_macro( (macname, argspec), ) # or spec = std_macro( (macname, optarg, numargs), ) # or spec = std_macro( spec ) # spec is already a `MacroSpec` -- no-op - `macname` is the name of the macro, without the leading backslash. - `argspec` is a string either characters "\*", "{" or "[", in which star indicates an optional asterisk character (e.g. starred macro variants), each curly brace specifies a mandatory argument and each square bracket specifies an optional argument in square brackets. For example, "{{\*[{" expects two mandatory arguments, then an optional star, an optional argument in square brackets, and then another mandatory argument. `argspec` may also be `None`, which is the same as ``argspec=''``. - `optarg` may be one of `True`, `False`, or `None`, corresponding to these possibilities: + if `True`, the macro expects as first argument an optional argument in square brackets. Then, `numargs` specifies the number of additional mandatory arguments to the command, given in usual curly braces (or simply as one TeX token like a single macro) + if `False`, the macro only expects a number of mandatory arguments given by `numargs`. The mandatory arguments are given in usual curly braces (or simply as one TeX token like a single macro) + if `None`, then `numargs` is a string like `argspec` above. I.e., ``std_macro(macname, None, argspec)`` is the same as ``std_macro(macname, argspec)``. - `numargs`: depends on `optarg`, see above. To make environment specifications (:py:class:`EnvironmentSpec`) instead of a macro specification, use the function :py:func:`std_environment()` instead. The helper function :py:func:`std_environment()` is a shorthand for calling this function with additional keyword arguments. An optional keyword argument `make_environment_spec=True` to the present function may be specified to return an `EnvironmentSpec` instead of a `MacroSpec`. In this case, you can further specify the `environment_is_math_mode=True|False` to specify whether of not the environment represents a math mode. """ if isinstance(macname, tuple): if len(args) != 0: raise TypeError( "No positional arguments expected if first argument is a tuple" ) args = tuple(macname[1:]) macname = macname[0] if isinstance(macname, MacroSpec): if len(args) != 0: raise TypeError( "No positional arguments expected if first argument is a MacroSpec" ) return macname if isinstance(macname, EnvironmentSpec): if len(args) != 0: raise TypeError( "No positional arguments expected if first argument is a EnvironmentSpec" ) return macname if len(args) == 1: # std_macro(macname, argspec) argspec = args[0] elif len(args) != 2: raise TypeError( "Wrong number of arguments for std_macro, macname={!r}, args={!r}".format( macname, args ) ) elif not args[0] and isinstance(args[1], _basestring): # argspec given in numargs argspec = args[1] else: argspec = "" if args[0]: argspec = "[" argspec += "{" * args[1] if kwargs.get("make_environment_spec", False): return EnvironmentSpec( macname, args_parser=MacroStandardArgsParser(argspec), is_math_mode=kwargs.get("environment_is_math_mode", False), ) return MacroSpec(macname, args_parser=MacroStandardArgsParser(argspec)) def std_environment(envname, *args, **kwargs): r""" Return an environment specification for the given environment. Syntax:: spec = std_environment(envname, argspec, is_math_mode=True|False) # or spec = std_environment(envname, optarg, numargs, is_math_mode=True|False) # or spec = std_environment( (envname, argspec), is_math_mode=True|False) # or spec = std_environment( (envname, optarg, numargs), is_math_mode=True|False) # or spec = std_environment( spec ) # spec is already a `EnvironmentSpec` -- no-op - `envname` is the name of the environment, i.e., the argument to ``\begin{...}``. - `argspec` is a string either characters "\*", "{" or "[", in which star indicates an optional asterisk character (e.g. starred environment variants), each curly brace specifies a mandatory argument and each square bracket specifies an optional argument in square brackets. For example, "{{\*[{" expects two mandatory arguments, then an optional star, an optional argument in square brackets, and then another mandatory argument. `argspec` may also be `None`, which is the same as ``argspec=''``. .. note:: See :py:class:`EnvironmentSpec` for an important remark about starred variants for environments. TL;DR: a starred verison of an environment is defined as a separate `EnvironmentSpec` with the star in the name and *not* using an ``argspec='*'``. - `optarg` may be one of `True`, `False`, or `None`, corresponding to these possibilities: + if `True`, the environment expects as first argument an optional argument in square brackets. Then, `numargs` specifies the number of additional mandatory arguments to the command, given in usual curly braces (or simply as one TeX token like a single environment) + if `False`, the environment only expects a number of mandatory arguments given by `numargs`. The mandatory arguments are given in usual curly braces (or simply as one TeX token like a single environment) + if `None`, then `numargs` is a string like `argspec` above. I.e., ``std_environment(envname, None, argspec)`` is the same as ``std_environment(envname, argspec)``. - `numargs`: depends on `optarg`, see above. - `is_math_mode`: if set to True, then the environment represents a math mode environment (e.g., 'equation', 'align', 'gather', etc.), i.e., whose contents should be parsed in an appropriate math mode. Note that `is_math_mode` *must* be given as a keyword argument, in contrast to all other arguments which must be positional (non-keyword) arguments. """ is_math_mode = kwargs.pop("is_math_mode", False) kwargs2 = dict(kwargs) kwargs2.update(make_environment_spec=True, environment_is_math_mode=is_math_mode) return std_macro(envname, *args, **kwargs2) def std_specials(specials_chars): r""" Return a latex specials specification for the given character sequence. Syntax:: spec = std_specials(specials_chars) where `specials_chars` is the sequence of characters that has a special LaTeX meaning, e.g. ``&`` or ``''``. This helper function only allows to create specs for simple specials without any argument parsing. For more complicated specials, you can instantiate a :py:class:`SpecialsSpec` directly. """ return SpecialsSpec(specials_chars, args_parser=None) # ------------------------------------------------------------------------------ class LatexContextDb(object): r""" Store a database of specifications of known macros, environments, and other latex specials. This might be, e.g., how many arguments a macro accepts, or how to determine the text representation of a macro or environment. When used with :py:class:`pylatexenc.latexwalker.LatexWalker`, the specifications describe mostly rules for parsing arguments of macros and environments, and which sequences of characters to consider as "latex specials". Specifications for macros, environments, and other specials are stored as :py:class:`MacroSpec`, :py:class:`EnvironmentSpec`, and :py:class:`SpecialsSpec` instances, respectively. When used with :py:class:`pylatexenc.latex2text.LatexNodes2Text`, the specifications for macros, environments, and other specials are stored as :py:class:`pylatexenc.latex2text.MacroTextSpec` , :py:class:`pylatexenc.latex2text.EnvironmentTextSpec`, and :py:class:`pylatexenc.latex2text.SpecialsTextSpec` instances, respectively. In fact, the objects stored in this database may be of any type, except that macro specifications must have an attribute `macroname`, environment specifications must have an attribute `environmentname`, and specials specification must have an attribute `specials_chars`. The `LatexContextDb` instance is meant to be (pseudo-)immutable. Once constructed and all the definitions added with :py:meth:`add_context_category()`, one should refrain from modifying it directly after providing it to, e.g., a :py:class:`~pylatexenc.latexwalker.LatexWalker` object. The reason is that the latex walker keeps track of what the latex context was when parsing nodes, and modifying the context will modify that stored information, too. Instead of being tempted to modify the object, create a new one with :py:meth:`filter_context()`. See :py:func:`pylatexenc.latexwalker.get_default_latex_context_db()` for the default latex context for `latexwalker` with a default collection of known latex macros and environments. See :py:func:`pylatexenc.latex2text.get_default_latex_context_db()` for the default latex context for `latex2text` with a set of text replacements for a collection of known macros and environments. """ def __init__(self, **kwargs): super(LatexContextDb, self).__init__(**kwargs) self.category_list = [] self.d = {} self.unknown_macro_spec = None self.unknown_environment_spec = None self.unknown_specials_spec = None def add_context_category( self, category, macros=[], environments=[], specials=[], prepend=False, insert_before=None, insert_after=None, ): r""" Register a category of macro and environment specifications in the context database. The category name `category` must not already exist in the database. The argument `macros` is an iterable (e.g., a list) of macro specification objects. The argument `environments` is an iterable (e.g., a list) of environment spec objects. Similarly, the `specials` argument is an iterable of latex specials spec instances. If you specify `prepend=True`, then macro and environment lookups will prioritize this category over other categories. Categories are normally searched for in the order they are registered to the database; if you specify `prepend=True`, then the new category is prepended to the existing list so that it is searched first. If `insert_before` is not `None`, then it must be a string; the definitions are inserted in the category list immediately before the given category name, or at the beginning of the list if the given category doesn't exist. If `insert_after` is not `None`, then it must be a string; the definitions are inserted in the category list immediately after the given category name, or at the end of the list if the given category doesn't exist. You may only specify one of `prepend=True`, `insert_before='...'` or `insert_after='...'`. """ if category in self.category_list: raise ValueError( "Category {} is already registered in the context database".format( category ) ) # ensure only one of these options is set if len([x for x in (prepend, insert_before, insert_after) if x]) > 1: raise TypeError( "add_context_category(): You may only specify one of " "prepend=True, insert_before=... or insert_after=..." ) if prepend: self.category_list.insert(0, category) elif insert_before: if insert_before in self.category_list: i = self.category_list.index(insert_before) else: i = 0 self.category_list.insert(i, category) elif insert_after: if insert_after in self.category_list: i = ( self.category_list.index(insert_after) + 1 ) # insert after found category else: i = len(self.category_list) self.category_list.insert(i, category) else: self.category_list.append(category) self.d[category] = { "macros": dict((m.macroname, m) for m in macros), "environments": dict((e.environmentname, e) for e in environments), "specials": dict((s.specials_chars, s) for s in specials), } def set_unknown_macro_spec(self, macrospec): r""" Set the macro spec to use when encountering a macro that is not in the database. """ self.unknown_macro_spec = macrospec def set_unknown_environment_spec(self, environmentspec): r""" Set the environment spec to use when encountering a LaTeX environment that is not in the database. """ self.unknown_environment_spec = environmentspec def set_unknown_specials_spec(self, specialsspec): r""" Set the latex specials spec to use when encountering a LaTeX environment that is not in the database. """ self.unknown_specials_spec = specialsspec def categories(self): r""" Return a list of valid category names that are registered in the current database context. """ return list(self.category_list) def get_macro_spec(self, macroname): r""" Look up a macro specification by macro name. The macro name is searched for in all categories one by one and the first match is returned. Returns a macro spec instance that matches the given `macroname`. If the macro name was not found, we return the default macro specification set by :py:meth:`set_unknown_macro_spec()` or `None` if no such spec was set. """ for cat in self.category_list: # search categories in the given order if macroname in self.d[cat]["macros"]: return self.d[cat]["macros"][macroname] return self.unknown_macro_spec def get_environment_spec(self, environmentname): r""" Look up an environment specification by environment name. The environment name is searched for in all categories one by one and the first match is returned. Returns the environment spec. If the environment name was not found, we return the default environment specification set by :py:meth:`set_unknown_environment_spec()` or `None` if no such spec was set. """ for cat in self.category_list: # search categories in the given order if environmentname in self.d[cat]["environments"]: return self.d[cat]["environments"][environmentname] return self.unknown_environment_spec def get_specials_spec(self, specials_chars): r""" Look up a "latex specials" specification by character sequence. The sequence name is searched for in all categories one by one and the first match is returned. If you are parsing a chunk of LaTeX code, you should use :py:meth:`test_for_specials()` instead. Unlike :py:meth:`test_for_specials()`, :py:meth:`get_specials_spec()` returns the first match regardless of matched length. [Rationale: we only need to worry about matching the longest specials sequence when parsing LaTeX code. Calling `get_specials_spec()` means one has already parsed the sequence and one is looking up additional specs on it.] Returns the specials spec. If the latex specials was not found, we return the default latex specials specification set by :py:meth:`set_unknown_specials_spec()` or `None` if no such spec was set. """ for cat in self.category_list: # search categories in the given order if specials_chars in self.d[cat]["specials"]: return self.d[cat]["specials"][specials_chars] return self.unknown_specials_spec def test_for_specials(self, s, pos, parsing_state=None): r""" Test the given position in the string for any LaTeX specials. The lookup proceeds by searching for in all categories one by one and the first match is returned, except that the longest match accross all categories is returned. For instance, a match of '``' in a later category will take precedence over a match of '`' in a earlier-searched category. Returns a specials spec instance, or `None` if no specials are detected at the position `pos`. """ best_match_len = 0 best_match_s = None for cat in self.category_list: # search categories in the given order for specials_chars in self.d[cat]["specials"].keys(): if len(specials_chars) > best_match_len and s.startswith( specials_chars, pos ): best_match_s = self.d[cat]["specials"][specials_chars] best_match_len = len(specials_chars) return best_match_s # this is None if no match def iter_macro_specs(self, categories=None): r""" Yield the macro specs corresponding to all macros in the given categories. If `categories` is `None`, then the known macro specs from all categories are provided in one long iterable sequence. Otherwise, `categories` should be a list or iterable of category names (e.g., 'latex-base') of macro specs to return. The macro specs from the different categories specified are concatenated into one long sequence which is yielded spec by spec. """ if categories is None: categories = self.category_list for c in categories: if c not in self.category_list: raise ValueError( "Invalid latex macro spec db category: {!r} (Expected one of {!r})".format( c, self.category_list ) ) for spec in self.d[c]["macros"].values(): yield spec def iter_environment_specs(self, categories=None): r""" Yield the environment specs corresponding to all environments in the given categories. If `categories` is `None`, then the known environment specs from all categories are provided in one long iterable sequence. Otherwise, `categories` should be a list or iterable of category names (e.g., 'latex-base') of environment specs to return. The environment specs from the different categories specified are concatenated into one long sequence which is yielded spec by spec. """ if categories is None: categories = self.category_list for c in categories: if c not in self.category_list: raise ValueError( "Invalid latex environment spec db category: {!r} (Expected one of {!r})".format( c, self.category_list ) ) for spec in self.d[c]["environments"].values(): yield spec def iter_specials_specs(self, categories=None): r""" Yield the specials specs corresponding to all environments in the given categories. If `categories` is `None`, then the known specials specs from all categories are provided in one long iterable sequence. Otherwise, `categories` should be a list or iterable of category names (e.g., 'latex-base') of specials specs to return. The specials specs from the different categories specified are concatenated into one long sequence which is yielded spec by spec. """ if categories is None: categories = self.category_list for c in categories: if c not in self.category_list: raise ValueError( "Invalid latex environment spec db category: {!r} (Expected one of {!r})".format( c, self.category_list ) ) for spec in self.d[c]["specials"].values(): yield spec def filter_context(self, keep_categories=[], exclude_categories=[], keep_which=[]): r""" Return a new :py:class:`LatexContextDb` instance where we only keep certain categories of macro and environment specifications. If `keep_categories` is set to a nonempty list, then the returned context will not contain any definitions that do not correspond to the specified categories. If `exclude_categories` is set to a nonempty list, then the returned context will not contain any definitions that correspond to the specified categories. It is explicitly fine to have category names in `keep_categories` and `exclude_categories` that don't exist in the present object (cf. :py:meth:`categories()`). The argument `keep_which`, if non-empty, specifies which definitions to keep. It should be a subset of the list ['macros', 'environments', 'specials']. The returned context will make a copy of the dictionaries that store the macro and environment specifications, but the specification classes (and corresponding argument parsers) might correspond to the same instances. I.e., the returned context is not a full deep copy. """ new_context = LatexContextDb() new_context.unknown_macro_spec = self.unknown_macro_spec new_context.unknown_environment_spec = self.unknown_environment_spec new_context.unknown_specials_spec = self.unknown_specials_spec keep_macros = not keep_which or "macros" in keep_which keep_environments = not keep_which or "environments" in keep_which keep_specials = not keep_which or "specials" in keep_which for cat in self.category_list: if keep_categories and cat not in keep_categories: continue if exclude_categories and cat in exclude_categories: continue # include this category new_context.add_context_category( cat, macros=self.d[cat]["macros"].values() if keep_macros else [], environments=self.d[cat]["environments"].values() if keep_environments else [], specials=self.d[cat]["specials"].values() if keep_specials else [], ) return new_context