diff options
Diffstat (limited to 'pygments/lexer.py')
| -rw-r--r-- | pygments/lexer.py | 153 |
1 files changed, 122 insertions, 31 deletions
diff --git a/pygments/lexer.py b/pygments/lexer.py index a22768a3..567e85f8 100644 --- a/pygments/lexer.py +++ b/pygments/lexer.py @@ -5,22 +5,28 @@ Base lexer classes. - :copyright: Copyright 2006-2010 by the Pygments team, see AUTHORS. + :copyright: Copyright 2006-2014 by the Pygments team, see AUTHORS. :license: BSD, see LICENSE for details. """ -import re +import re, itertools from pygments.filter import apply_filters, Filter from pygments.filters import get_filter_by_name from pygments.token import Error, Text, Other, _TokenType from pygments.util import get_bool_opt, get_int_opt, get_list_opt, \ - make_analysator + make_analysator, text_type, add_metaclass, iteritems __all__ = ['Lexer', 'RegexLexer', 'ExtendedRegexLexer', 'DelegatingLexer', - 'LexerContext', 'include', 'bygroups', 'using', 'this'] + 'LexerContext', 'include', 'inherit', 'bygroups', 'using', 'this'] +_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) @@ -36,6 +42,7 @@ class LexerMeta(type): return type.__new__(cls, name, bases, d) +@add_metaclass(LexerMeta) class Lexer(object): """ Lexer for a specific language. @@ -49,7 +56,9 @@ class Lexer(object): ``ensurenl`` Make sure that the input ends with a newline (default: True). This is required for some lexers that consume input linewise. - *New in Pygments 1.3.* + + .. versionadded:: 1.3 + ``tabsize`` If given and greater than 0, expand tabs in the input (default: 0). ``encoding`` @@ -66,16 +75,17 @@ class Lexer(object): #: Shortcuts for the lexer aliases = [] - #: fn match rules + #: File name globs filenames = [] - #: fn alias filenames + #: Secondary file name globs alias_filenames = [] - #: mime types + #: MIME types mimetypes = [] - __metaclass__ = LexerMeta + #: Priority, should multiple lexers match and no content is provided + priority = 0 def __init__(self, **options): self.options = options @@ -127,7 +137,7 @@ class Lexer(object): Also preprocess the text, i.e. expand tabs and strip it if wanted and applies registered filters. """ - if not isinstance(text, unicode): + if not isinstance(text, text_type): if self.encoding == 'guess': try: text = text.decode('utf-8') @@ -142,10 +152,26 @@ class Lexer(object): raise ImportError('To enable chardet encoding guessing, ' 'please install the chardet library ' 'from http://chardet.feedparser.org/') - enc = chardet.detect(text) - text = text.decode(enc['encoding']) + # 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(u'\ufeff'): + text = text[len(u'\ufeff'):] + else: + if text.startswith(u'\ufeff'): + text = text[len(u'\ufeff'):] + # text now *is* a unicode string text = text.replace('\r\n', '\n') text = text.replace('\r', '\n') @@ -168,7 +194,9 @@ class Lexer(object): def get_tokens_unprocessed(self, text): """ - Return an iterable of (tokentype, value) pairs. + 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. """ @@ -221,6 +249,16 @@ class include(str): pass +class _inherit(object): + """ + Indicates the a state should inherit from its superclass. + """ + def __repr__(self): + return 'inherit' + +inherit = _inherit() + + class combined(tuple): """ Indicates a state combined from multiple states. @@ -274,12 +312,14 @@ def bygroups(*args): if data: yield match.start(i + 1), action, data else: - if ctx: - ctx.pos = match.start(i + 1) - for item in action(lexer, _PseudoMatch(match.start(i + 1), - match.group(i + 1)), ctx): - if item: - yield item + 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 @@ -409,12 +449,15 @@ class RegexLexerMeta(LexerMeta): tokens.extend(cls._process_state(unprocessed, processed, str(tdef))) continue + if isinstance(tdef, _inherit): + # processed already + continue assert type(tdef) is tuple, "wrong rule def %r" % tdef try: rex = cls._process_regex(tdef[0], rflags) - except Exception, err: + except Exception as err: raise ValueError("uncompilable regex %r in state %r of %r: %s" % (tdef[0], state, cls, err)) @@ -433,31 +476,74 @@ class RegexLexerMeta(LexerMeta): """Preprocess a dictionary of token definitions.""" processed = cls._all_tokens[name] = {} tokendefs = tokendefs or cls.tokens[name] - for state in tokendefs.keys(): + 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 itertools.chain((cls,), cls.__mro__): + toks = c.__dict__.get('tokens', {}) + + for state, items in iteritems(toks): + curitems = tokens.get(state) + if curitems is None: + 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: + 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 not hasattr(cls, '_tokens'): + 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.tokens) + cls._tokens = cls.process_tokendef('', cls.get_tokendefs()) return type.__call__(cls, *args, **kwds) +@add_metaclass(RegexLexerMeta) class RegexLexer(Lexer): """ 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. """ - __metaclass__ = RegexLexerMeta #: Flags for compiling the regular expressions. #: Defaults to MULTILINE. @@ -525,10 +611,10 @@ class RegexLexer(Lexer): try: if text[pos] == '\n': # at EOL, reset state to "root" - pos += 1 statestack = ['root'] statetokens = tokendefs['root'] yield pos, Text, u'\n' + pos += 1 continue yield pos, Error, text[pos] pos += 1 @@ -587,7 +673,13 @@ class ExtendedRegexLexer(RegexLexer): if new_state is not None: # state transition if isinstance(new_state, tuple): - ctx.stack.extend(new_state) + for state in new_state: + if state == '#pop': + ctx.stack.pop() + elif state == '#push': + ctx.stack.append(ctx.stack[-1]) + else: + ctx.stack.append(state) elif isinstance(new_state, int): # pop del ctx.stack[new_state:] @@ -603,10 +695,10 @@ class ExtendedRegexLexer(RegexLexer): break if text[ctx.pos] == '\n': # at EOL, reset state to "root" - ctx.pos += 1 ctx.stack = ['root'] statetokens = tokendefs['root'] yield ctx.pos, Text, u'\n' + ctx.pos += 1 continue yield ctx.pos, Error, text[ctx.pos] ctx.pos += 1 @@ -630,7 +722,7 @@ def do_insertions(insertions, tokens): """ insertions = iter(insertions) try: - index, itokens = insertions.next() + index, itokens = next(insertions) except StopIteration: # no insertions for item in tokens: @@ -656,7 +748,7 @@ def do_insertions(insertions, tokens): realpos += len(it_value) oldi = index - i try: - index, itokens = insertions.next() + index, itokens = next(insertions) except StopIteration: insleft = False break # not strictly necessary @@ -671,8 +763,7 @@ def do_insertions(insertions, tokens): yield realpos, t, v realpos += len(v) try: - index, itokens = insertions.next() + index, itokens = next(insertions) except StopIteration: insleft = False break # not strictly necessary - |