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, 43 insertions, 0 deletions

diff --git a/pygments/modeline.py b/pygments/modeline.py
new file mode 100644
index 00000000..2200f1cf
--- /dev/null
+++ b/pygments/modeline.py
@@ -0,0 +1,43 @@
+# -*- coding: utf-8 -*-
+"""
+    pygments.modeline
+    ~~~~~~~~~~~~~~~~~
+
+    A simple modeline parser (based on pymodeline).
+
+    :copyright: Copyright 2006-2015 by the Pygments team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+import re
+
+__all__ = ['get_filetype_from_buffer']
+
+
+modeline_re = re.compile(r'''
+    (?: vi | vim | ex ) (?: [<=>]? \d* )? :
+    .* (?: ft | filetype | syn | syntax ) = ( [^:\s]+ )
+''', re.VERBOSE)
+
+
+def get_filetype_from_line(l):
+    m = modeline_re.search(l)
+    if m:
+        return m.group(1)
+
+
+def get_filetype_from_buffer(buf, max_lines=5):
+    """
+    Scan the buffer for modelines and return filetype if one is found.
+    """
+    lines = buf.splitlines()
+    for l in lines[-1:-max_lines-1:-1]:
+        ret = get_filetype_from_line(l)
+        if ret:
+            return ret
+    for l in lines[max_lines:-1:-1]:
+        ret = get_filetype_from_line(l)
+        if ret:
+            return ret
+
+    return None