Add support for partials and path segments for Handlebars.

This introduces support for some missing features to the Handlebars lexer:
Partials and path segments. Partials mostly appeared to work before, but the
`>` in `{{> ... }}` would appear as a syntax error, as could other
components of the partial. This change introduces support for:

* Standard partials: `{{> partialName}}`
* Partials with parameters: `{{> partialName varname="value"}}`
* Ddynamic partials: `{{> (partialFunc)}}`
* Ddynamic partials with lookups: `{{> (lookup ../path "partialName")}}`
* Partial blocks: `{{> @partial-block}}`
* Inline partials: `{{#*inline}}..{{/inline}}`

It also introduces support for path segments, which can reference content in
the current context or in a parent context. For instance, `this.name`,
`this/name`, `./name`, `../name`, `this/name`, etc. These are all now tracked
as variables.

1 files changed, 82 insertions, 0 deletions

diff --git a/external/rst-directive.py b/external/rst-directive.py
new file mode 100644
index 00000000..f81677b6
--- /dev/null
+++ b/external/rst-directive.py
@@ -0,0 +1,82 @@
+# -*- coding: utf-8 -*-
+"""
+    The Pygments reStructuredText directive
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+    This fragment is a Docutils_ 0.5 directive that renders source code
+    (to HTML only, currently) via Pygments.
+
+    To use it, adjust the options below and copy the code into a module
+    that you import on initialization.  The code then automatically
+    registers a ``sourcecode`` directive that you can use instead of
+    normal code blocks like this::
+
+        .. sourcecode:: python
+
+            My code goes here.
+
+    If you want to have different code styles, e.g. one with line numbers
+    and one without, add formatters with their names in the VARIANTS dict
+    below.  You can invoke them instead of the DEFAULT one by using a
+    directive option::
+
+        .. sourcecode:: python
+            :linenos:
+
+            My code goes here.
+
+    Look at the `directive documentation`_ to get all the gory details.
+
+    .. _Docutils: http://docutils.sf.net/
+    .. _directive documentation:
+       http://docutils.sourceforge.net/docs/howto/rst-directives.html
+
+    :copyright: Copyright 2006-2015 by the Pygments team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+# Options
+# ~~~~~~~
+
+# Set to True if you want inline CSS styles instead of classes
+INLINESTYLES = False
+
+from pygments.formatters import HtmlFormatter
+
+# The default formatter
+DEFAULT = HtmlFormatter(noclasses=INLINESTYLES)
+
+# Add name -> formatter pairs for every variant you want to use
+VARIANTS = {
+    # 'linenos': HtmlFormatter(noclasses=INLINESTYLES, linenos=True),
+}
+
+
+from docutils import nodes
+from docutils.parsers.rst import directives, Directive
+
+from pygments import highlight
+from pygments.lexers import get_lexer_by_name, TextLexer
+
+class Pygments(Directive):
+    """ Source code syntax hightlighting.
+    """
+    required_arguments = 1
+    optional_arguments = 0
+    final_argument_whitespace = True
+    option_spec = dict([(key, directives.flag) for key in VARIANTS])
+    has_content = True
+
+    def run(self):
+        self.assert_has_content()
+        try:
+            lexer = get_lexer_by_name(self.arguments[0])
+        except ValueError:
+            # no lexer found - use the text one instead of an exception
+            lexer = TextLexer()
+        # take an arbitrary option if more than one is given
+        formatter = self.options and VARIANTS[list(self.options)[0]] or DEFAULT
+        parsed = highlight(u'\n'.join(self.content), lexer, formatter)
+        return [nodes.raw('', parsed, format='html')]
+
+directives.register_directive('sourcecode', Pygments)