JezK
Edit File: lexer.py
""" pygments.lexer ~~~~~~~~~~~~~~ Base lexer classes. :copyright: Copyright 2006-2022 by the Pygments team, see AUTHORS. :license: BSD, see LICENSE for details. """ import re import sys import time from pip._vendor.pygments.filter import apply_filters, Filter from pip._vendor.pygments.filters import get_filter_by_name from pip._vendor.pygments.token import Error, Text, Other, _TokenType from pip._vendor.pygments.util import get_bool_opt, get_int_opt, get_list_opt, \ make_analysator, Future, guess_decode from pip._vendor.pygments.regexopt import regex_opt __all__ = ['Lexer', 'RegexLexer', 'ExtendedRegexLexer', 'DelegatingLexer', 'LexerContext', 'include', 'inherit', 'bygroups', 'using', 'this', 'default', 'words'] _encoding_map = [(b'\xef\xbb\xbf', 'utf-8'), (b'\xff\xfe\0\0', 'utf-32'), (b'\0\0\xfe\xff', 'utf-32be'), (b'\xff\xfe', 'utf-16'), (b'\xfe\xff', 'utf-16be')] _default_analyse = staticmethod(lambda x: 0.0) class LexerMeta(type): """ This metaclass automagically converts ``analyse_text`` methods into static methods which always return float values. """ def __new__(mcs, name, bases, d): if 'analyse_text' in d: d['analyse_text'] = make_analysator(d['analyse_text']) return type.__new__(mcs, name, bases, d) class Lexer(metaclass=LexerMeta): """ Lexer for a specific language. Basic options recognized: ``stripnl`` Strip leading and trailing newlines from the input (default: True). ``stripall`` Strip all leading and trailing whitespace from the input (default: False). ``ensurenl`` Make sure that the input ends with a newline (default: True). This is required for some lexers that consume input linewise. .. versionadded:: 1.3 ``tabsize`` If given and greater than 0, expand tabs in the input (default: 0). ``encoding`` If given, must be an encoding name. This encoding will be used to convert the input string to Unicode, if it is not already a Unicode string (default: ``'guess'``, which uses a simple UTF-8 / Locale / Latin1 detection. Can also be ``'chardet'`` to use the chardet library, if it is installed. ``inencoding`` Overrides the ``encoding`` if given. """ #: Name of the lexer name = None #: URL of the language specification/definition url = None #: Shortcuts for the lexer aliases = [] #: File name globs filenames = [] #: Secondary file name globs alias_filenames = [] #: MIME types mimetypes = [] #: Priority, should multiple lexers match and no content is provided priority = 0 def __init__(self, **options): self.options = options self.stripnl = get_bool_opt(options, 'stripnl', True) self.stripall = get_bool_opt(options, 'stripall', False) self.ensurenl = get_bool_opt(options, 'ensurenl', True) self.tabsize = get_int_opt(options, 'tabsize', 0) self.encoding = options.get('encoding', 'guess') self.encoding = options.get('inencoding') or self.encoding self.filters = [] for filter_ in get_list_opt(options, 'filters', ()): self.add_filter(filter_) def __repr__(self): if self.options: return '<pygments.lexers.%s with %r>' % (self.__class__.__name__, self.options) else: return '<pygments.lexers.%s>' % self.__class__.__name__ def add_filter(self, filter_, **options): """ Add a new stream filter to this lexer. """ if not isinstance(filter_, Filter): filter_ = get_filter_by_name(filter_, **options) self.filters.append(filter_) def analyse_text(text): """ Has to return a float between ``0`` and ``1`` that indicates if a lexer wants to highlight this text. Used by ``guess_lexer``. If this method returns ``0`` it won't highlight it in any case, if it returns ``1`` highlighting with this lexer is guaranteed. The `LexerMeta` metaclass automatically wraps this function so that it works like a static method (no ``self`` or ``cls`` parameter) and the return value is automatically converted to `float`. If the return value is an object that is boolean `False` it's the same as if the return values was ``0.0``. """ def get_tokens(self, text, unfiltered=False): """ Return an iterable of (tokentype, value) pairs generated from `text`. If `unfiltered` is set to `True`, the filtering mechanism is bypassed even if filters are defined. Also preprocess the text, i.e. expand tabs and strip it if wanted and applies registered filters. """ if not isinstance(text, str): if self.encoding == 'guess': text, _ = guess_decode(text) elif self.encoding == 'chardet': try: from pip._vendor import chardet except ImportError as e: raise ImportError('To enable chardet encoding guessing, ' 'please install the chardet library ' 'from http://chardet.feedparser.org/') from e # check for BOM first decoded = None for bom, encoding in _encoding_map: if text.startswith(bom): decoded = text[len(bom):].decode(encoding, 'replace') break # no BOM found, so use chardet if decoded is None: enc = chardet.detect(text[:1024]) # Guess using first 1KB decoded = text.decode(enc.get('encoding') or 'utf-8', 'replace') text = decoded else: text = text.decode(self.encoding) if text.startswith('\ufeff'): text = text[len('\ufeff'):] else: if text.startswith('\ufeff'): text = text[len('\ufeff'):] # text now *is* a unicode string text = text.replace('\r\n', '\n') text = text.replace('\r', '\n') if self.stripall: text = text.strip() elif self.stripnl: text = text.strip('\n') if self.tabsize > 0: text = text.expandtabs(self.tabsize) if self.ensurenl and not text.endswith('\n'): text += '\n' def streamer(): for _, t, v in self.get_tokens_unprocessed(text): yield t, v stream = streamer() if not unfiltered: stream = apply_filters(stream, self.filters, self) return stream def get_tokens_unprocessed(self, text): """ Return an iterable of (index, tokentype, value) pairs where "index" is the starting position of the token within the input text. In subclasses, implement this method as a generator to maximize effectiveness. """ raise NotImplementedError class DelegatingLexer(Lexer): """ This lexer takes two lexer as arguments. A root lexer and a language lexer. First everything is scanned using the language lexer, afterwards all ``Other`` tokens are lexed using the root lexer. The lexers from the ``template`` lexer package use this base lexer. """ def __init__(self, _root_lexer, _language_lexer, _needle=Other, **options): self.root_lexer = _root_lexer(**options) self.language_lexer = _language_lexer(**options) self.needle = _needle Lexer.__init__(self, **options) def get_tokens_unprocessed(self, text): buffered = '' insertions = [] lng_buffer = [] for i, t, v in self.language_lexer.get_tokens_unprocessed(text): if t is self.needle: if lng_buffer: insertions.append((len(buffered), lng_buffer)) lng_buffer = [] buffered += v else: lng_buffer.append((i, t, v)) if lng_buffer: insertions.append((len(buffered), lng_buffer)) return do_insertions(insertions, self.root_lexer.get_tokens_unprocessed(buffered)) # ------------------------------------------------------------------------------ # RegexLexer and ExtendedRegexLexer # class include(str): # pylint: disable=invalid-name """ Indicates that a state should include rules from another state. """ pass class _inherit: """ Indicates the a state should inherit from its superclass. """ def __repr__(self): return 'inherit' inherit = _inherit() # pylint: disable=invalid-name class combined(tuple): # pylint: disable=invalid-name """ Indicates a state combined from multiple states. """ def __new__(cls, *args): return tuple.__new__(cls, args) def __init__(self, *args): # tuple.__init__ doesn't do anything pass class _PseudoMatch: """ A pseudo match object constructed from a string. """ def __init__(self, start, text): self._text = text self._start = start def start(self, arg=None): return self._start def end(self, arg=None): return self._start + len(self._text) def group(self, arg=None): if arg: raise IndexError('No such group') return self._text def groups(self): return (self._text,) def groupdict(self): return {} def bygroups(*args): """ Callback that yields multiple actions for each group in the match. """ def callback(lexer, match, ctx=None): for i, action in enumerate(args): if action is None: continue elif type(action) is _TokenType: data = match.group(i + 1) if data: yield match.start(i + 1), action, data else: data = match.group(i + 1) if data is not None: if ctx: ctx.pos = match.start(i + 1) for item in action(lexer, _PseudoMatch(match.start(i + 1), data), ctx): if item: yield item if ctx: ctx.pos = match.end() return callback class _This: """ Special singleton used for indicating the caller class. Used by ``using``. """ this = _This() def using(_other, **kwargs): """ Callback that processes the match with a different lexer. The keyword arguments are forwarded to the lexer, except `state` which is handled separately. `state` specifies the state that the new lexer will start in, and can be an enumerable such as ('root', 'inline', 'string') or a simple string which is assumed to be on top of the root state. Note: For that to work, `_other` must not be an `ExtendedRegexLexer`. """ gt_kwargs = {} if 'state' in kwargs: s = kwargs.pop('state') if isinstance(s, (list, tuple)): gt_kwargs['stack'] = s else: gt_kwargs['stack'] = ('root', s) if _other is this: def callback(lexer, match, ctx=None): # if keyword arguments are given the callback # function has to create a new lexer instance if kwargs: # XXX: cache that somehow kwargs.update(lexer.options) lx = lexer.__class__(**kwargs) else: lx = lexer s = match.start() for i, t, v in lx.get_tokens_unprocessed(match.group(), **gt_kwargs): yield i + s, t, v if ctx: ctx.pos = match.end() else: def callback(lexer, match, ctx=None): # XXX: cache that somehow kwargs.update(lexer.options) lx = _other(**kwargs) s = match.start() for i, t, v in lx.get_tokens_unprocessed(match.group(), **gt_kwargs): yield i + s, t, v if ctx: ctx.pos = match.end() return callback class default: """ Indicates a state or state action (e.g. #pop) to apply. For example default('#pop') is equivalent to ('', Token, '#pop') Note that state tuples may be used as well. .. versionadded:: 2.0 """ def __init__(self, state): self.state = state class words(Future): """ Indicates a list of literal words that is transformed into an optimized regex that matches any of the words. .. versionadded:: 2.0 """ def __init__(self, words, prefix='', suffix=''): self.words = words self.prefix = prefix self.suffix = suffix def get(self): return regex_opt(self.words, prefix=self.prefix, suffix=self.suffix) class RegexLexerMeta(LexerMeta): """ Metaclass for RegexLexer, creates the self._tokens attribute from self.tokens on the first instantiation. """ def _process_regex(cls, regex, rflags, state): """Preprocess the regular expression component of a token definition.""" if isinstance(regex, Future): regex = regex.get() return re.compile(regex, rflags).match def _process_token(cls, token): """Preprocess the token component of a token definition.""" assert type(token) is _TokenType or callable(token), \ 'token type must be simple type or callable, not %r' % (token,) return token def _process_new_state(cls, new_state, unprocessed, processed): """Preprocess the state transition action of a token definition.""" if isinstance(new_state, str): # an existing state if new_state == '#pop': return -1 elif new_state in unprocessed: return (new_state,) elif new_state == '#push': return new_state elif new_state[:5] == '#pop:': return -int(new_state[5:]) else: assert False, 'unknown new state %r' % new_state elif isinstance(new_state, combined): # combine a new state from existing ones tmp_state = '_tmp_%d' % cls._tmpname cls._tmpname += 1 itokens = [] for istate in new_state: assert istate != new_state, 'circular state ref %r' % istate itokens.extend(cls._process_state(unprocessed, processed, istate)) processed[tmp_state] = itokens return (tmp_state,) elif isinstance(new_state, tuple): # push more than one state for istate in new_state: assert (istate in unprocessed or istate in ('#pop', '#push')), \ 'unknown new state ' + istate return new_state else: assert False, 'unknown new state def %r' % new_state def _process_state(cls, unprocessed, processed, state): """Preprocess a single state definition.""" assert type(state) is str, "wrong state name %r" % state assert state[0] != '#', "invalid state name %r" % state if state in processed: return processed[state] tokens = processed[state] = [] rflags = cls.flags for tdef in unprocessed[state]: if isinstance(tdef, include): # it's a state reference assert tdef != state, "circular state reference %r" % state tokens.extend(cls._process_state(unprocessed, processed, str(tdef))) continue if isinstance(tdef, _inherit): # should be processed already, but may not in the case of: # 1. the state has no counterpart in any parent # 2. the state includes more than one 'inherit' continue if isinstance(tdef, default): new_state = cls._process_new_state(tdef.state, unprocessed, processed) tokens.append((re.compile('').match, None, new_state)) continue assert type(tdef) is tuple, "wrong rule def %r" % tdef try: rex = cls._process_regex(tdef[0], rflags, state) except Exception as err: raise ValueError("uncompilable regex %r in state %r of %r: %s" % (tdef[0], state, cls, err)) from err token = cls._process_token(tdef[1]) if len(tdef) == 2: new_state = None else: new_state = cls._process_new_state(tdef[2], unprocessed, processed) tokens.append((rex, token, new_state)) return tokens def process_tokendef(cls, name, tokendefs=None): """Preprocess a dictionary of token definitions.""" processed = cls._all_tokens[name] = {} tokendefs = tokendefs or cls.tokens[name] for state in list(tokendefs): cls._process_state(tokendefs, processed, state) return processed def get_tokendefs(cls): """ Merge tokens from superclasses in MRO order, returning a single tokendef dictionary. Any state that is not defined by a subclass will be inherited automatically. States that *are* defined by subclasses will, by default, override that state in the superclass. If a subclass wishes to inherit definitions from a superclass, it can use the special value "inherit", which will cause the superclass' state definition to be included at that point in the state. """ tokens = {} inheritable = {} for c in cls.__mro__: toks = c.__dict__.get('tokens', {}) for state, items in toks.items(): curitems = tokens.get(state) if curitems is None: # N.b. because this is assigned by reference, sufficiently # deep hierarchies are processed incrementally (e.g. for # A(B), B(C), C(RegexLexer), B will be premodified so X(B) # will not see any inherits in B). tokens[state] = items try: inherit_ndx = items.index(inherit) except ValueError: continue inheritable[state] = inherit_ndx continue inherit_ndx = inheritable.pop(state, None) if inherit_ndx is None: continue # Replace the "inherit" value with the items curitems[inherit_ndx:inherit_ndx+1] = items try: # N.b. this is the index in items (that is, the superclass # copy), so offset required when storing below. new_inh_ndx = items.index(inherit) except ValueError: pass else: inheritable[state] = inherit_ndx + new_inh_ndx return tokens def __call__(cls, *args, **kwds): """Instantiate cls after preprocessing its token definitions.""" if '_tokens' not in cls.__dict__: cls._all_tokens = {} cls._tmpname = 0 if hasattr(cls, 'token_variants') and cls.token_variants: # don't process yet pass else: cls._tokens = cls.process_tokendef('', cls.get_tokendefs()) return type.__call__(cls, *args, **kwds) class RegexLexer(Lexer, metaclass=RegexLexerMeta): """ Base for simple stateful regular expression-based lexers. Simplifies the lexing process so that you need only provide a list of states and regular expressions. """ #: Flags for compiling the regular expressions. #: Defaults to MULTILINE. flags = re.MULTILINE #: At all time there is a stack of states. Initially, the stack contains #: a single state 'root'. The top of the stack is called "the current state". #: #: Dict of ``{'state': [(regex, tokentype, new_state), ...], ...}`` #: #: ``new_state`` can be omitted to signify no state transition. #: If ``new_state`` is a string, it is pushed on the stack. This ensure #: the new current state is ``new_state``. #: If ``new_state`` is a tuple of strings, all of those strings are pushed #: on the stack and the current state will be the last element of the list. #: ``new_state`` can also be ``combined('state1', 'state2', ...)`` #: to signify a new, anonymous state combined from the rules of two #: or more existing ones. #: Furthermore, it can be '#pop' to signify going back one step in #: the state stack, or '#push' to push the current state on the stack #: again. Note that if you push while in a combined state, the combined #: state itself is pushed, and not only the state in which the rule is #: defined. #: #: The tuple can also be replaced with ``include('state')``, in which #: case the rules from the state named by the string are included in the #: current one. tokens = {} def get_tokens_unprocessed(self, text, stack=('root',)): """ Split ``text`` into (tokentype, text) pairs. ``stack`` is the initial stack (default: ``['root']``) """ pos = 0 tokendefs = self._tokens statestack = list(stack) statetokens = tokendefs[statestack[-1]] while 1: for rexmatch, action, new_state in statetokens: m = rexmatch(text, pos) if m: if action is not None: if type(action) is _TokenType: yield pos, action, m.group() else: yield from action(self, m) pos = m.end() if new_state is not None: # state transition if isinstance(new_state, tuple): for state in new_state: if state == '#pop': if len(statestack) > 1: statestack.pop() elif state == '#push': statestack.append(statestack[-1]) else: statestack.append(state) elif isinstance(new_state, int): # pop, but keep at least one state on the stack # (random code leading to unexpected pops should # not allow exceptions) if abs(new_state) >= len(statestack): del statestack[1:] else: del statestack[new_state:] elif new_state == '#push': statestack.append(statestack[-1]) else: assert False, "wrong state def: %r" % new_state statetokens = tokendefs[statestack[-1]] break else: # We are here only if all state tokens have been considered # and there was not a match on any of them. try: if text[pos] == '\n': # at EOL, reset state to "root" statestack = ['root'] statetokens = tokendefs['root'] yield pos, Text, '\n' pos += 1 continue yield pos, Error, text[pos] pos += 1 except IndexError: break class LexerContext: """ A helper object that holds lexer position data. """ def __init__(self, text, pos, stack=None, end=None): self.text = text self.pos = pos self.end = end or len(text) # end=0 not supported ;-) self.stack = stack or ['root'] def __repr__(self): return 'LexerContext(%r, %r, %r)' % ( self.text, self.pos, self.stack) class ExtendedRegexLexer(RegexLexer): """ A RegexLexer that uses a context object to store its state. """ def get_tokens_unprocessed(self, text=None, context=None): """ Split ``text`` into (tokentype, text) pairs. If ``context`` is given, use this lexer context instead. """ tokendefs = self._tokens if not context: ctx = LexerContext(text, 0) statetokens = tokendefs['root'] else: ctx = context statetokens = tokendefs[ctx.stack[-1]] text = ctx.text while 1: for rexmatch, action, new_state in statetokens: m = rexmatch(text, ctx.pos, ctx.end) if m: if action is not None: if type(action) is _TokenType: yield ctx.pos, action, m.group() ctx.pos = m.end() else: yield from action(self, m, ctx) if not new_state: # altered the state stack? statetokens = tokendefs[ctx.stack[-1]] # CAUTION: callback must set ctx.pos! if new_state is not None: # state transition if isinstance(new_state, tuple): for state in new_state: if state == '#pop': if len(ctx.stack) > 1: ctx.stack.pop() elif state == '#push': ctx.stack.append(ctx.stack[-1]) else: ctx.stack.append(state) elif isinstance(new_state, int): # see RegexLexer for why this check is made if abs(new_state) >= len(ctx.stack): del ctx.stack[1:] else: del ctx.stack[new_state:] elif new_state == '#push': ctx.stack.append(ctx.stack[-1]) else: assert False, "wrong state def: %r" % new_state statetokens = tokendefs[ctx.stack[-1]] break else: try: if ctx.pos >= ctx.end: break if text[ctx.pos] == '\n': # at EOL, reset state to "root" ctx.stack = ['root'] statetokens = tokendefs['root'] yield ctx.pos, Text, '\n' ctx.pos += 1 continue yield ctx.pos, Error, text[ctx.pos] ctx.pos += 1 except IndexError: break def do_insertions(insertions, tokens): """ Helper for lexers which must combine the results of several sublexers. ``insertions`` is a list of ``(index, itokens)`` pairs. Each ``itokens`` iterable should be inserted at position ``index`` into the token stream given by the ``tokens`` argument. The result is a combined token stream. TODO: clean up the code here. """ insertions = iter(insertions) try: index, itokens = next(insertions) except StopIteration: # no insertions yield from tokens return realpos = None insleft = True # iterate over the token stream where we want to insert # the tokens from the insertion list. for i, t, v in tokens: # first iteration. store the position of first item if realpos is None: realpos = i oldi = 0 while insleft and i + len(v) >= index: tmpval = v[oldi:index - i] if tmpval: yield realpos, t, tmpval realpos += len(tmpval) for it_index, it_token, it_value in itokens: yield realpos, it_token, it_value realpos += len(it_value) oldi = index - i try: index, itokens = next(insertions) except StopIteration: insleft = False break # not strictly necessary if oldi < len(v): yield realpos, t, v[oldi:] realpos += len(v) - oldi # leftover tokens while insleft: # no normal tokens, set realpos to zero realpos = realpos or 0 for p, t, v in itokens: yield realpos, t, v realpos += len(v) try: index, itokens = next(insertions) except StopIteration: insleft = False break # not strictly necessary class ProfilingRegexLexerMeta(RegexLexerMeta): """Metaclass for ProfilingRegexLexer, collects regex timing info.""" def _process_regex(cls, regex, rflags, state): if isinstance(regex, words): rex = regex_opt(regex.words, prefix=regex.prefix, suffix=regex.suffix) else: rex = regex compiled = re.compile(rex, rflags) def match_func(text, pos, endpos=sys.maxsize): info = cls._prof_data[-1].setdefault((state, rex), [0, 0.0]) t0 = time.time() res = compiled.match(text, pos, endpos) t1 = time.time() info[0] += 1 info[1] += t1 - t0 return res return match_func class ProfilingRegexLexer(RegexLexer, metaclass=ProfilingRegexLexerMeta): """Drop-in replacement for RegexLexer that does profiling of its regexes.""" _prof_data = [] _prof_sort_index = 4 # defaults to time per call def get_tokens_unprocessed(self, text, stack=('root',)): # this needs to be a stack, since using(this) will produce nested calls self.__class__._prof_data.append({}) yield from RegexLexer.get_tokens_unprocessed(self, text, stack) rawdata = self.__class__._prof_data.pop() data = sorted(((s, repr(r).strip('u\'').replace('\\\\', '\\')[:65], n, 1000 * t, 1000 * t / n) for ((s, r), (n, t)) in rawdata.items()), key=lambda x: x[self._prof_sort_index], reverse=True) sum_total = sum(x[3] for x in data) print() print('Profiling result for %s lexing %d chars in %.3f ms' % (self.__class__.__name__, len(text), sum_total)) print('=' * 110) print('%-20s %-64s ncalls tottime percall' % ('state', 'regex')) print('-' * 110) for d in data: print('%-20s %-65s %5d %8.4f %8.4f' % d) print('=' * 110)