Add wdiff to authors/changes.

4 files changed, 6 insertions, 762 deletions

diff --git a/AUTHORS b/AUTHORS
index c5ed18b7..795876c2 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -89,7 +89,8 @@ Other contributors, listed alphabetically, are:
 * Tim Howard -- BlitzMax lexer
 * Dustin Howett -- Logos lexer
 * Ivan Inozemtsev -- Fantom lexer
-* Hiroaki Itoh -- Shell console rewrite, Lexers for PowerShell session, MSDOS session, BC
+* Hiroaki Itoh -- Shell console rewrite, Lexers for PowerShell session,
+  MSDOS session, BC, WDiff
 * Brian R. Jackson -- Tea lexer
 * Christian Jann -- ShellSession lexer
 * Dennis Kaarsemaker -- sources.list lexer
diff --git a/CHANGES b/CHANGES
index 81e22722..edf4e0b6 100644
--- a/CHANGES
+++ b/CHANGES
@@ -17,6 +17,7 @@ Version 2.2
   * TypoScript (#1173)
   * Varnish config (PR#554)
   * Clean (PR#503)
+  * WDiff (PR#513)
 
 - Added `lexers.find_lexer_class_by_name()`. (#1203)
 
diff --git a/pygments/lexers/diff.py b/pygments/lexers/diff.py
index 2056fbff..726b49ad 100644
--- a/pygments/lexers/diff.py
+++ b/pygments/lexers/diff.py
@@ -118,12 +118,12 @@ class WDiffLexer(RegexLexer):
     * if target files of wdiff contain "[-", "-]", "{+", "+}",
       especially they are unbalanced, this lexer will get confusing.
 
-    .. versionadded:: 2.1
+    .. versionadded:: 2.2
     """
 
     name = 'WDiff'
-    aliases = ['wdiff',]
-    filenames = ['*.wdiff',]
+    aliases = ['wdiff']
+    filenames = ['*.wdiff']
     mimetypes = []
 
     flags = re.MULTILINE | re.DOTALL
diff --git a/tests/examplefiles/wdiff_example2.wdiff b/tests/examplefiles/wdiff_example2.wdiff
deleted file mode 100644
index 1a746fe5..00000000
--- a/tests/examplefiles/wdiff_example2.wdiff
+++ /dev/null
@@ -1,758 +0,0 @@
-.. -*- mode: rst -*-
-
-[-..-]
-
-{+{+..+} highlight:: [-python-] {+python+}+}
-
-====================
-Write your own lexer
-====================
-
-If a lexer for your favorite language is missing in the Pygments package, you
-can easily write your own and extend Pygments.
-
-All you need can be found inside the :mod:`pygments.lexer` module.  As you can
-read in the :doc:`API documentation <api>`, a lexer is a class that is
-initialized with some keyword arguments (the lexer options) and that provides a
-:meth:`.get_tokens_unprocessed()` method which is given a string or unicode
-object with the data to [-lex.-] {+[-parse.-] {+lex.+}+}
-
-The :meth:`.get_tokens_unprocessed()` method must return an iterator or iterable
-containing tuples in the form ``(index, token, value)``.  Normally you don't
-need to do this since there are {+[-numerous-]+} base lexers [-that-] {+{+that+} do most of the work and [-that-] {+that+}+}
-you can subclass.
-
-
-RegexLexer
-==========
-
-[-The-]
-
-{+[-A very powerful (but quite easy to use)-]
-
-{+The+}+} lexer [-base-] {+{+base+} class used by almost all of Pygments' [-lexers-] {+lexers+}+} is the
-:class:`RegexLexer`.  This
-{+[-lexer base-]+} class allows you to define lexing rules in terms of
-*regular expressions* for different *states*.
-
-States are groups of regular expressions that are matched against the input
-string at the *current position*.  If one of these expressions matches, a
-corresponding action is performed [-(such as-] {+[-(normally-] {+(such as+}+} yielding a token with a specific
-[-type,-]
-{+[-type),-]
-{+type,+} or changing [-state),-] {+state),+}+} the current position is set to where the last match
-ended and the matching process continues with the first regex of the current
-state.
-
-Lexer states are kept [-on-] {+[-in-] {+on+}+} a {+[-state-]+} stack: each time a new state is entered, the new
-state is pushed onto the stack.  The most basic lexers (like the `DiffLexer`)
-just need one state.
-
-Each state is defined as a list of tuples in the form (`regex`, `action`,
-`new_state`) where the last item is optional.  In the most basic form, `action`
-is a token type (like `Name.Builtin`).  That means: When `regex` matches, emit a
-token with the match text and type `tokentype` and push `new_state` on the state
-stack.  If the new state is ``'#pop'``, the topmost state is popped from the
-stack instead.  [-To-] {+[-(To-]  {+To+}+} pop more than one state, use ``'#pop:2'`` and so [-on.-] {+[-on.)-] {+on.+}+}
-``'#push'`` is a synonym for pushing the current state on the stack.
-
-The following example shows the `DiffLexer` from the builtin lexers.  Note that
-it contains some additional attributes `name`, `aliases` and `filenames` which
-aren't required for a lexer.  They are used by the builtin lexer lookup
-functions. [-::-]
-
-{+[-.. sourcecode:: python-] {+::+}+}
-
-    from pygments.lexer import RegexLexer
-    from pygments.token import *
-
-    class DiffLexer(RegexLexer):
-        name = 'Diff'
-        aliases = ['diff']
-        filenames = ['*.diff']
-
-        tokens = {
-            'root': [
-                (r' .*\n', Text),
-                (r'\+.*\n', Generic.Inserted),
-                (r'-.*\n', Generic.Deleted),
-                (r'@.*\n', Generic.Subheading),
-                (r'Index.*\n', Generic.Heading),
-                (r'=.*\n', Generic.Heading),
-                (r'.*\n', Text),
-            ]
-        }
-
-As you can see this lexer only uses one state.  When the lexer starts scanning
-the text, it first checks if the current character is a space.  If this is true
-it scans everything until newline and returns the {+[-parsed-]+} data as [-a-] {+{+a+}+} `Text` [-token-] {+[-token.-] {+token+} (which
-is the "no special highlighting" [-token).-] {+token).+}+}
-
-If this rule doesn't match, it checks if the current char is a plus sign.  And
-so on.
-
-If no rule matches at the current position, the current char is emitted as an
-`Error` token that indicates a [-lexing-] {+[-parsing-] {+lexing+}+} error, and the position is increased by
-[-one.-]
-{+[-1.-]
-{+one.+}+}
-
-
-Adding and testing a new lexer
-==============================
-
-To make [-Pygments-] {+[-pygments-] {+Pygments+}+} aware of your new lexer, you have to perform the following
-steps:
-
-First, change to the current directory containing the [-Pygments-] {+[-pygments-] {+Pygments+}+} source code:
-
-.. [-code-block::-] {+[-sourcecode::-] {+code-block::+}+} console
-
-    $ cd .../pygments-main
-
-[-Select-]
-
-{+{+Select+} a matching module under ``pygments/lexers``, or create a new module for
-your lexer [-class.-] {+class.+}+}
-
-Next, make sure the lexer is known from outside of the module.  All modules in
-the ``pygments.lexers`` specify ``__all__``. For example, [-``esoteric.py`` sets::-] {+[-``other.py`` sets:
-
-.. sourcecode:: python-] {+``esoteric.py`` sets::+}+}
-
-    __all__ = ['BrainfuckLexer', 'BefungeLexer', ...]
-
-Simply add the name of your lexer class to this list.
-
-Finally the lexer can be made [-publicly-] {+[-publically-] {+publicly+}+} known by rebuilding the lexer mapping:
-
-.. [-code-block::-] {+[-sourcecode::-] {+code-block::+}+} console
-
-    $ make mapfiles
-
-To test the new lexer, store an example file with the proper extension in
-``tests/examplefiles``.  For example, to test your ``DiffLexer``, add a
-``tests/examplefiles/example.diff`` containing a sample diff output.
-
-Now you can use pygmentize to render your example to HTML:
-
-.. [-code-block::-] {+[-sourcecode::-] {+code-block::+}+} console
-
-    $ ./pygmentize -O full -f html -o /tmp/example.html tests/examplefiles/example.diff
-
-Note that this [-explicitly-] {+[-explicitely-] {+explicitly+}+} calls the ``pygmentize`` in the current directory
-by preceding it with ``./``. This ensures your modifications are used.
-Otherwise a possibly already installed, unmodified version without your new
-lexer would have been called from the system search path (``$PATH``).
-
-To view the result, open ``/tmp/example.html`` in your browser.
-
-Once the example renders as expected, you should run the complete test suite:
-
-.. [-code-block::-] {+[-sourcecode::-] {+code-block::+}+} console
-
-    $ make test
-
-[-It-]
-
-{+{+It+} also tests that your lexer fulfills the lexer API and certain invariants,
-such as that the concatenation of all token text is the same as the input [-text.-] {+text.+}+}
-
-
-Regex Flags
-===========
-
-You can either define regex flags [-locally-] {+{+locally+}+} in the regex (``r'(?x)foo bar'``) or
-[-globally-]
-{+{+globally+}+} by adding a `flags` attribute to your lexer class.  If no attribute is
-defined, it defaults to `re.MULTILINE`.  For more [-information-] {+[-informations-] {+information+}+} about regular
-expression flags see the [-page about-] {+{+page about+}+} `regular expressions`_ {+[-help page-]+} in the [-Python-] {+[-python-] {+Python+}+}
-documentation.
-
-.. _regular expressions: [-http://docs.python.org/library/re.html#regular-expression-syntax-] {+[-http://docs.python.org/lib/re-syntax.html-] {+http://docs.python.org/library/re.html#regular-expression-syntax+}+}
-
-
-Scanning multiple tokens at once
-================================
-
-[-So-]
-
-{+{+So+} far, the `action` element in the rule tuple of regex, action and state has
-been a single token type.  Now we look at the first of several other possible
-[-values.-]
-{+values.+}+}
-
-Here is a more complex lexer that highlights INI files.  INI files consist of
-sections, comments and [-``key-] {+[-key-] {+``key+}+} = [-value`` pairs::-] {+[-value pairs:
-
-.. sourcecode:: python-] {+value`` pairs::+}+}
-
-    from pygments.lexer import RegexLexer, bygroups
-    from pygments.token import *
-
-    class IniLexer(RegexLexer):
-        name = 'INI'
-        aliases = ['ini', 'cfg']
-        filenames = ['*.ini', '*.cfg']
-
-        tokens = {
-            'root': [
-                (r'\s+', Text),
-                (r';.*?$', Comment),
-                (r'\[.*?\]$', Keyword),
-                (r'(.*?)(\s*)(=)(\s*)(.*?)$',
-                 bygroups(Name.Attribute, Text, Operator, Text, String))
-            ]
-        }
-
-The lexer first looks for whitespace, comments and section names.  [-Later-] {+[-And later-]  {+Later+}+} it
-looks for a line that looks like a key, value pair, separated by an ``'='``
-sign, and optional whitespace.
-
-The `bygroups` helper [-yields-] {+[-makes sure that-] {+yields+}+} each [-capturing-] {+{+capturing+}+} group [-in-] {+[-is yielded-] {+in+} the [-regex-] {+regex+}+} with a different
-token type.  First the `Name.Attribute` token, then a `Text` token for the
-optional whitespace, after that a `Operator` token for the equals sign. Then a
-`Text` token for the whitespace again.  The rest of the line is returned as
-`String`.
-
-Note that for this to work, every part of the match must be inside a capturing
-group (a ``(...)``), and there must not be any nested capturing groups.  If you
-nevertheless need a group, use a non-capturing group defined using this syntax:
-[-``(?:some|words|here)``-]
-{+[-``r'(?:some|words|here)'``-]
-{+``(?:some|words|here)``+}+} (note the ``?:`` after the beginning parenthesis).
-
-If you find yourself needing a capturing group inside the regex which shouldn't
-be part of the output but is used in the regular expressions for backreferencing
-(eg: ``r'(<(foo|bar)>)(.*?)(</\2>)'``), you can pass `None` to the bygroups
-function and {+[-it will skip-]+} that group will be skipped in the output.
-
-
-Changing states
-===============
-
-Many lexers need multiple states to work as expected.  For example, some
-languages allow multiline comments to be nested.  Since this is a recursive
-pattern it's impossible to lex just using regular expressions.
-
-Here is [-a-] {+[-the solution:
-
-.. sourcecode:: python-] {+a+} lexer that recognizes C++ style comments (multi-line with ``/* */``
-and single-line with ``//`` until end of [-line)::-] {+line)::+}+}
-
-    from pygments.lexer import RegexLexer
-    from pygments.token import *
-
-    class [-CppCommentLexer(RegexLexer):-] {+[-ExampleLexer(RegexLexer):-] {+CppCommentLexer(RegexLexer):+}+}
-        name = 'Example Lexer with states'
-
-        tokens = {
-            'root': [
-                (r'[^/]+', Text),
-                (r'/\*', Comment.Multiline, 'comment'),
-                (r'//.*?$', Comment.Singleline),
-                (r'/', Text)
-            ],
-            'comment': [
-                (r'[^*/]', Comment.Multiline),
-                (r'/\*', Comment.Multiline, '#push'),
-                (r'\*/', Comment.Multiline, '#pop'),
-                (r'[*/]', Comment.Multiline)
-            ]
-        }
-
-This lexer starts lexing in the ``'root'`` state. It tries to match as much as
-possible until it finds a slash (``'/'``).  If the next character after the slash
-is [-an asterisk-] {+[-a star-] {+an asterisk+}+} (``'*'``) the `RegexLexer` sends those two characters to the
-output stream marked as `Comment.Multiline` and continues [-lexing-] {+[-parsing-] {+lexing+}+} with the rules
-defined in the ``'comment'`` state.
-
-If there wasn't [-an asterisk-] {+[-a star-] {+an asterisk+}+} after the slash, the `RegexLexer` checks if it's a
-[-Singleline-]
-{+[-singleline-]
-{+Singleline+}+} comment [-(i.e.-] {+[-(eg:-] {+(i.e.+}+} followed by a second slash).  If this also wasn't the
-case it must be a single [-slash,-] {+[-slash-] {+slash,+} which is not a comment [-starter-] {+starter+}+} (the separate
-regex for a single slash must also be given, else the slash would be marked as
-an error token).
-
-Inside the ``'comment'`` state, we do the same thing again.  Scan until the
-lexer finds a star or slash.  If it's the opening of a multiline comment, push
-the ``'comment'`` state on the stack and continue scanning, again in the
-``'comment'`` state.  Else, check if it's the end of the multiline comment.  If
-yes, pop one state from the stack.
-
-Note: If you pop from an empty stack you'll get an `IndexError`.  (There is an
-easy way to prevent this from happening: don't ``'#pop'`` in the root state).
-
-If the `RegexLexer` encounters a newline that is flagged as an error token, the
-stack is emptied and the lexer continues scanning in the ``'root'`` state.  This
-[-can help-]
-{+[-helps-]
-{+can help+}+} producing error-tolerant highlighting for erroneous input, e.g. when a
-single-line string is not closed.
-
-
-Advanced state tricks
-=====================
-
-There are a few more things you can do with states:
-
-- You can push multiple states onto the stack if you give a tuple instead of a
-  simple string as the third item in a rule tuple.  For example, if you want to
-  match a comment containing a directive, something [-like:-] {+[-like::-] {+like:+}
-
-  .. code-block:: [-text-] {+text+}+}
-
-      /* <processing directive>    rest of comment */
-
-  you can use this [-rule::-] {+[-rule:
-
-  .. sourcecode:: python-] {+rule::+}+}
-
-      tokens = {
-          'root': [
-              (r'/\* <', Comment, ('comment', 'directive')),
-              ...
-          ],
-          'directive': [
-              (r'[^>]*', Comment.Directive),
-              (r'>', Comment, '#pop'),
-          ],
-          'comment': [
-              (r'[^*]+', Comment),
-              (r'\*/', Comment, '#pop'),
-              (r'\*', Comment),
-          ]
-      }
-
-  When this encounters the above sample, first ``'comment'`` and ``'directive'``
-  are pushed onto the stack, then the lexer continues in the directive state
-  until it finds the closing ``>``, then it continues in the comment state until
-  the closing ``*/``.  Then, both states are popped from the stack again and
-  lexing continues in the root state.
-
-  .. versionadded:: 0.9
-     The tuple can contain the special ``'#push'`` and ``'#pop'`` (but not
-     ``'#pop:n'``) directives.
-
-
-- You can include the rules of a state in the definition of another.  This is
-  done by using `include` from [-`pygments.lexer`::-] {+[-`pygments.lexer`:
-
-  .. sourcecode:: python-] {+`pygments.lexer`::+}+}
-
-      from pygments.lexer import RegexLexer, bygroups, include
-      from pygments.token import *
-
-      class ExampleLexer(RegexLexer):
-          tokens = {
-              'comments': [
-                  (r'/\*.*?\*/', Comment),
-                  (r'//.*?\n', Comment),
-              ],
-              'root': [
-                  include('comments'),
-                  (r'(function )(\w+)( {)',
-                   bygroups(Keyword, Name, Keyword), 'function'),
-                  (r'.', Text),
-              ],
-              'function': [
-                  (r'[^}/]+', Text),
-                  include('comments'),
-                  (r'/', Text),
-                  [-(r'\}',-]
-                  {+[-(r'}',-]
-                  {+(r'\}',+}+} Keyword, '#pop'),
-              ]
-          }
-
-  This is a hypothetical lexer for a language that consist of functions and
-  comments.  Because comments can occur at toplevel and in functions, we need
-  rules for comments in both states.  As you can see, the `include` helper saves
-  repeating rules that occur more than once (in this example, the state
-  ``'comment'`` will never be entered by the lexer, as it's only there to be
-  included in ``'root'`` and ``'function'``).
-
-- Sometimes, you may want to "combine" a state from existing ones.  This is
-  possible with the [-`combined`-] {+[-`combine`-] {+`combined`+}+} helper from `pygments.lexer`.
-
-  If you, instead of a new state, write ``combined('state1', 'state2')`` as the
-  third item of a rule tuple, a new anonymous state will be formed from state1
-  and state2 and if the rule matches, the lexer will enter this state.
-
-  This is not used very often, but can be helpful in some cases, such as the
-  `PythonLexer`'s string literal processing.
-
-- If you want your lexer to start lexing in a different state you can modify the
-  stack by [-overriding-] {+[-overloading-] {+overriding+}+} the `get_tokens_unprocessed()` [-method::-] {+[-method:
-
-  .. sourcecode:: python-] {+method::+}+}
-
-      from pygments.lexer import RegexLexer
-
-      class [-ExampleLexer(RegexLexer):-] {+[-MyLexer(RegexLexer):-] {+ExampleLexer(RegexLexer):+}+}
-          tokens = {...}
-
-          def get_tokens_unprocessed(self, [-text,-] {+[-text):
-              stack = ['root', 'otherstate']-] {+text,+} stack=('root', [-'otherstate')):-] {+'otherstate')):+}+}
-              for item in RegexLexer.get_tokens_unprocessed(text, stack):
-                  yield item
-
-  Some lexers like the `PhpLexer` use this to make the leading ``<?php``
-  preprocessor comments optional.  Note that you can crash the lexer easily by
-  putting values into the stack that don't exist in the token map.  Also
-  removing ``'root'`` from the stack can result in strange errors!
-
-- [-In-] {+[-An-] {+In+} some lexers, a state should be popped if anything is encountered that isn't
-  matched by a rule in the state.  You could use [-an-] {+an+}+} empty regex at the end of
-  [-the-] {+[-a-]
-  {+the+}+} state list, [-but-] {+[-combined with ``'#pop'``, can
-  act as-] {+but+} Pygments [-provides-] {+provides+}+} a [-more-] {+[-return point-] {+more+} obvious way of spelling that:
-  ``default('#pop')`` is equivalent to ``('', Text, '#pop')``.
-
-  .. versionadded:: 2.0
-
-
-Subclassing lexers [-derived-] {+derived+}+} from [-RegexLexer-] {+{+RegexLexer+}
-==========================================
-
-.. versionadded:: 1.6
-
-Sometimes multiple languages are very similar, but should still be lexed by
-different lexer classes.
-
-When [-subclassing-] {+subclassing+}+} a [-lexer-] {+{+lexer+} derived from RegexLexer, the ``tokens`` dictionaries
-defined in the parent and child class are merged.  For example::
-
-      from pygments.lexer import RegexLexer, inherit
-      from pygments.token import *
-
-      class BaseLexer(RegexLexer):
-          tokens = {
-              'root': [
-                  ('[a-z]+', Name),
-                  (r'/\*', Comment, 'comment'),
-                  ('"', String, 'string'),
-                  ('\s+', Text),
-              ],
-              'string': [
-                  ('[^"]+', String),
-                  ('"', String, '#pop'),
-              ],
-              'comment': [
-                  ...
-              ],
-          }
-
-      class DerivedLexer(BaseLexer):
-          tokens = {
-              'root': [
-                  ('[0-9]+', Number),
-                  inherit,
-              ],
-              'string': [
-                  (r'[^"\\]+', String),
-                  (r'\\.', String.Escape),
-                  ('"', String, '#pop'),
-              ],
-          }
-
-The `BaseLexer` defines two states, lexing names and strings.  The
-`DerivedLexer` defines its own tokens dictionary, which extends the definitions
-of the base lexer:
-
-* The [-"root"-] {+"root"+}+} state [-has-] {+{+has+} an additional rule and then the special object `inherit`,
-  which tells Pygments to insert the token definitions of the parent class [-at-] {+at+}+}
-  that [-point.-] {+[-doesn't have a clear end marker.-] {+point.+}
-
-* The "string" state is replaced entirely, since there is not `inherit` rule.
-
-* The "comment" state is inherited [-entirely.-] {+entirely.+}+}
-
-
-Using multiple lexers
-=====================
-
-Using multiple lexers for the same input can be tricky.  One of the easiest
-combination techniques is shown here: You can replace the [-action-] {+[-token type-] {+action+}+} entry in a rule
-tuple {+[-(the second item)-]+} with a lexer class.  The matched text will then be lexed with that lexer,
-and the resulting tokens will be yielded.
-
-For example, look at this stripped-down HTML [-lexer::-] {+[-lexer:
-
-.. sourcecode:: python-] {+lexer::+}+}
-
-    from pygments.lexer import RegexLexer, bygroups, using
-    from pygments.token import *
-    from [-pygments.lexers.javascript-] {+[-pygments.lexers.web-] {+pygments.lexers.javascript+}+} import JavascriptLexer
-
-    class HtmlLexer(RegexLexer):
-        name = 'HTML'
-        aliases = ['html']
-        filenames = ['*.html', '*.htm']
-
-        flags = re.IGNORECASE | re.DOTALL
-        tokens = {
-            'root': [
-                ('[^<&]+', Text),
-                ('&.*?;', Name.Entity),
-                (r'<\s*script\s*', Name.Tag, ('script-content', 'tag')),
-                (r'<\s*[a-zA-Z0-9:]+', Name.Tag, 'tag'),
-                (r'<\s*/\s*[a-zA-Z0-9:]+\s*>', Name.Tag),
-            ],
-            'script-content': [
-                (r'(.+?)(<\s*/\s*script\s*>)',
-                 bygroups(using(JavascriptLexer), Name.Tag),
-                 '#pop'),
-            ]
-        }
-
-Here the content of a ``<script>`` tag is passed to a newly created instance of
-a `JavascriptLexer` and not processed by the `HtmlLexer`.  This is done using
-the `using` helper that takes the other lexer class as its parameter.
-
-Note the combination of `bygroups` and `using`.  This makes sure that the
-content up to the ``</script>`` end tag is processed by the `JavascriptLexer`,
-while the end tag is yielded as a normal token with the `Name.Tag` type.
-
-{+[-As an additional goodie, if the lexer class is replaced by `this` (imported from
-`pygments.lexer`), the "other" lexer will be the current one (because you cannot
-refer to the current class within the code that runs at class definition time).-]+}
-
-Also note the ``(r'<\s*script\s*', Name.Tag, ('script-content', 'tag'))`` rule.
-Here, two states are pushed onto the state stack, ``'script-content'`` and
-``'tag'``.  That means that first ``'tag'`` is processed, which will [-lex-] {+[-parse-] {+lex+}+}
-attributes and the closing ``>``, then the ``'tag'`` state is popped and the
-next state on top of the stack will be ``'script-content'``.
-
-[-Since-]
-
-{+{+Since+} you cannot refer to the class currently being defined, use `this`
-(imported from `pygments.lexer`) to refer to the current lexer class, i.e.
-``using(this)``.  This construct may seem unnecessary, but this is often the
-most obvious way of lexing arbitrary syntax between fixed delimiters without
-introducing deeply nested [-states.-] {+states.+}+}
-
-The `using()` helper has a special keyword argument, `state`, which works as
-follows: if given, the lexer to use initially is not in the ``"root"`` state,
-but in the state given by this argument.  This [-does-] {+[-*only* works-] {+does+} not [-work-] {+work+}+} with [-advanced-] {+[-a `RegexLexer`.-] {+advanced+}
-`RegexLexer` subclasses such as `ExtendedRegexLexer` (see [-below).-] {+below).+}+}
-
-Any other keywords arguments passed to `using()` are added to the keyword
-arguments used to create the lexer.
-
-
-Delegating Lexer
-================
-
-Another approach for nested lexers is the `DelegatingLexer` which is for example
-used for the template engine lexers.  It takes two lexers as arguments on
-initialisation: a `root_lexer` and a `language_lexer`.
-
-The input is processed as follows: First, the whole text is lexed with the
-`language_lexer`.  All tokens yielded with [-the special-] {+[-a-] {+the special+}+} type of ``Other`` are
-then concatenated and given to the `root_lexer`.  The language tokens of the
-`language_lexer` are then inserted into the `root_lexer`'s token stream at the
-appropriate positions. [-::-]
-
-{+[-.. sourcecode:: python-] {+::+}+}
-
-    from pygments.lexer import DelegatingLexer
-    from pygments.lexers.web import HtmlLexer, PhpLexer
-
-    class HtmlPhpLexer(DelegatingLexer):
-        def __init__(self, **options):
-            super(HtmlPhpLexer, self).__init__(HtmlLexer, PhpLexer, **options)
-
-This procedure ensures that e.g. HTML with template tags in it is highlighted
-correctly even if the template tags are put into HTML tags or attributes.
-
-If you want to change the needle token ``Other`` to something else, you can give
-the lexer another token type as the third [-parameter::-] {+[-parameter:
-
-.. sourcecode:: python-] {+parameter::+}+}
-
-    DelegatingLexer.__init__(MyLexer, OtherLexer, Text, **options)
-
-
-Callbacks
-=========
-
-Sometimes the grammar of a language is so complex that a lexer would be unable
-to [-process-] {+[-parse-] {+process+}+} it just by using regular expressions and stacks.
-
-For this, the `RegexLexer` allows callbacks to be given in rule tuples, instead
-of token types (`bygroups` and `using` are nothing else but preimplemented
-callbacks).  The callback must be a function taking two arguments:
-
-* the lexer itself
-* the match object for the last matched rule
-
-The callback must then return an iterable of (or simply yield) ``(index,
-tokentype, value)`` tuples, which are then just passed through by
-`get_tokens_unprocessed()`.  The ``index`` here is the position of the token in
-the input string, ``tokentype`` is the normal token type (like `Name.Builtin`),
-and ``value`` the associated part of the input string.
-
-You can see an example [-here::-] {+[-here:
-
-.. sourcecode:: python-] {+here::+}+}
-
-    from pygments.lexer import RegexLexer
-    from pygments.token import Generic
-
-    class HypotheticLexer(RegexLexer):
-
-        def headline_callback(lexer, match):
-            equal_signs = match.group(1)
-            text = match.group(2)
-            yield match.start(), Generic.Headline, equal_signs + text + equal_signs
-
-        tokens = {
-            'root': [
-                (r'(=+)(.*?)(\1)', headline_callback)
-            ]
-        }
-
-If the regex for the `headline_callback` matches, the function is called with
-the match object.  Note that after the callback is done, processing continues
-normally, that is, after the end of the previous match.  The callback has no
-possibility to influence the position.
-
-There are not really any simple examples for lexer callbacks, but you can see
-them in action e.g. in the [-`SMLLexer` class in `ml.py`_.-] {+[-`compiled.py`_ source code-] {+`SMLLexer` class+} in [-the `CLexer` and
-`JavaLexer` classes.-] {+`ml.py`_.+}+}
-
-.. [-_ml.py: http://bitbucket.org/birkenfeld/pygments-main/src/tip/pygments/lexers/ml.py-] {+[-_compiled.py: http://bitbucket.org/birkenfeld/pygments-main/src/tip/pygments/lexers/compiled.py-] {+_ml.py: http://bitbucket.org/birkenfeld/pygments-main/src/tip/pygments/lexers/ml.py+}+}
-
-
-The ExtendedRegexLexer class
-============================
-
-The `RegexLexer`, even with callbacks, unfortunately isn't powerful enough for
-the funky syntax rules of {+[-some-]+} languages {+[-that will go unnamed,-]+} such as Ruby.
-
-But fear not; even then you don't have to abandon the regular expression
-[-approach:-]
-{+[-approach. For-]
-{+approach:+}+} Pygments has a subclass of `RegexLexer`, the `ExtendedRegexLexer`.
-All features known from RegexLexers are available here too, and the tokens are
-specified in exactly the same way, *except* for one detail:
-
-The `get_tokens_unprocessed()` method holds its internal state data not as local
-variables, but in an instance of the `pygments.lexer.LexerContext` class, and
-that instance is passed to callbacks as a third argument. This means that you
-can modify the lexer state in callbacks.
-
-The `LexerContext` class has the following members:
-
-* `text` -- the input text
-* `pos` -- the current starting position that is used for matching regexes
-* `stack` -- a list containing the state stack
-* `end` -- the maximum position to which regexes are matched, this defaults to
-  the length of `text`
-
-Additionally, the `get_tokens_unprocessed()` method can be given a
-`LexerContext` instead of a string and will then process this context instead of
-creating a new one for the string argument.
-
-Note that because you can set the current position to anything in the callback,
-it won't be automatically be set by the caller after the callback is finished.
-For example, this is how the hypothetical lexer above would be written with the
-[-`ExtendedRegexLexer`::-]
-{+[-`ExtendedRegexLexer`:
-
-.. sourcecode:: python-]
-{+`ExtendedRegexLexer`::+}+}
-
-    from pygments.lexer import ExtendedRegexLexer
-    from pygments.token import Generic
-
-    class ExHypotheticLexer(ExtendedRegexLexer):
-
-        def headline_callback(lexer, match, ctx):
-            equal_signs = match.group(1)
-            text = match.group(2)
-            yield match.start(), Generic.Headline, equal_signs + text + equal_signs
-            ctx.pos = match.end()
-
-        tokens = {
-            'root': [
-                (r'(=+)(.*?)(\1)', headline_callback)
-            ]
-        }
-
-This might sound confusing (and it can really be). But it is needed, and for an
-example look at the Ruby lexer in [-`ruby.py`_.-] {+[-`agile.py`_.-] {+`ruby.py`_.+}+}
-
-.. [-_ruby.py:-] {+[-_agile.py: https://bitbucket.org/birkenfeld/pygments-main/src/tip/pygments/lexers/agile.py
-
-
-Filtering-] {+_ruby.py:+} https://bitbucket.org/birkenfeld/pygments-main/src/tip/pygments/lexers/ruby.py
-
-
-Handling Lists of Keywords
-==========================
-
-For a relatively short list (hundreds) you can construct an optimized regular
-expression directly using ``words()`` (longer lists, see next section).  This
-function handles a few things for you automatically, including escaping
-metacharacters and Python's first-match rather than longest-match in
-alternations.  Feel free to put the lists themselves in
-``pygments/lexers/_$lang_builtins.py`` (see examples there), and generated by
-code if possible.
-
-An example of using ``words()`` is something like::
-
-    from pygments.lexer import RegexLexer, words, Name
-
-    class MyLexer(RegexLexer):
-
-        tokens = {
-            'root': [
-                (words(('else', 'elseif'), suffix=r'\b'), Name.Builtin),
-                (r'\w+', Name),
-            ],
-        }
-
-As you can see, you can add ``prefix`` and ``suffix`` parts to the constructed
-regex.
-
-
-[-Modifying-]
-
-
-{+Modifying+}+} Token Streams
-=======================
-
-Some languages ship a lot of builtin functions (for example PHP).  The total
-amount of those functions differs from system to system because not everybody
-has every extension installed.  In the case of PHP there are over 3000 builtin
-functions.  That's an [-incredibly-] {+[-incredible-] {+incredibly+}+} huge amount of functions, much more than you
-[-want to-]
-{+[-can-]
-{+want to+}+} put into a regular expression.
-
-But because only `Name` tokens can be function names [-this is-] {+[-it's-] {+this is+}+} solvable by
-overriding the ``get_tokens_unprocessed()`` method.  The following lexer
-subclasses the `PythonLexer` so that it highlights some additional names as
-pseudo [-keywords::-] {+[-keywords:
-
-.. sourcecode:: python-] {+keywords::+}+}
-
-    from [-pygments.lexers.python-] {+[-pygments.lexers.agile-] {+pygments.lexers.python+}+} import PythonLexer
-    from pygments.token import Name, Keyword
-
-    class MyPythonLexer(PythonLexer):
-        EXTRA_KEYWORDS = [-set(('foo',-] {+[-['foo',-] {+set(('foo',+}+} 'bar', 'foobar', 'barfoo', 'spam', [-'eggs'))-] {+[-'eggs']-] {+'eggs'))+}+}
-
-        def get_tokens_unprocessed(self, text):
-            for index, token, value in PythonLexer.get_tokens_unprocessed(self, text):
-                if token is Name and value in self.EXTRA_KEYWORDS:
-                    yield index, Keyword.Pseudo, value
-                else:
-                    yield index, token, value
-
-The `PhpLexer` and `LuaLexer` use this method to resolve builtin functions.
-
-{+[-.. note:: Do not confuse this with the :doc:`filter <filters>` system.-]+}