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, 110 insertions, 0 deletions

diff --git a/tests/test_regexopt.py b/tests/test_regexopt.py
new file mode 100644
index 00000000..6322c735
--- /dev/null
+++ b/tests/test_regexopt.py
@@ -0,0 +1,110 @@
+# -*- coding: utf-8 -*-
+"""
+    Tests for pygments.regexopt
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+    :copyright: Copyright 2006-2015 by the Pygments team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+import re
+import random
+import unittest
+import itertools
+
+from pygments.regexopt import regex_opt
+
+ALPHABET = ['a', 'b', 'c', 'd', 'e']
+
+try:
+    from itertools import combinations_with_replacement
+    N_TRIES = 15
+except ImportError:
+    # Python 2.6
+    def combinations_with_replacement(iterable, r):
+        pool = tuple(iterable)
+        n = len(pool)
+        for indices in itertools.product(range(n), repeat=r):
+            if sorted(indices) == list(indices):
+                yield tuple(pool[i] for i in indices)
+    N_TRIES = 9
+
+
+class RegexOptTestCase(unittest.TestCase):
+
+    def generate_keywordlist(self, length):
+        return [''.join(p) for p in
+                combinations_with_replacement(ALPHABET, length)]
+
+    def test_randomly(self):
+        # generate a list of all possible keywords of a certain length using
+        # a restricted alphabet, then choose some to match and make sure only
+        # those do
+        for n in range(3, N_TRIES):
+            kwlist = self.generate_keywordlist(n)
+            to_match = random.sample(kwlist,
+                                     random.randint(1, len(kwlist) - 1))
+            no_match = set(kwlist) - set(to_match)
+            rex = re.compile(regex_opt(to_match))
+            self.assertEqual(rex.groups, 1)
+            for w in to_match:
+                self.assertTrue(rex.match(w))
+            for w in no_match:
+                self.assertFalse(rex.match(w))
+
+    def test_prefix(self):
+        opt = regex_opt(('a', 'b'), prefix=r':{1,2}')
+        print(opt)
+        rex = re.compile(opt)
+        self.assertFalse(rex.match('a'))
+        self.assertTrue(rex.match('::a'))
+        self.assertFalse(rex.match(':::')) # fullmatch
+
+    def test_suffix(self):
+        opt = regex_opt(('a', 'b'), suffix=r':{1,2}')
+        print(opt)
+        rex = re.compile(opt)
+        self.assertFalse(rex.match('a'))
+        self.assertTrue(rex.match('a::'))
+        self.assertFalse(rex.match(':::')) # fullmatch
+
+    def test_suffix_opt(self):
+        # test that detected suffixes remain sorted.
+        opt = regex_opt(('afoo', 'abfoo'))
+        print(opt)
+        rex = re.compile(opt)
+        m = rex.match('abfoo')
+        self.assertEqual(5, m.end())
+
+    def test_different_length_grouping(self):
+        opt = regex_opt(('a', 'xyz'))
+        print(opt)
+        rex = re.compile(opt)
+        self.assertTrue(rex.match('a'))
+        self.assertTrue(rex.match('xyz'))
+        self.assertFalse(rex.match('b'))
+        self.assertEqual(1, rex.groups)
+
+    def test_same_length_grouping(self):
+        opt = regex_opt(('a', 'b'))
+        print(opt)
+        rex = re.compile(opt)
+        self.assertTrue(rex.match('a'))
+        self.assertTrue(rex.match('b'))
+        self.assertFalse(rex.match('x'))
+
+        self.assertEqual(1, rex.groups)
+        groups = rex.match('a').groups()
+        self.assertEqual(('a',), groups)
+
+    def test_same_length_suffix_grouping(self):
+        opt = regex_opt(('a', 'b'), suffix='(m)')
+        print(opt)
+        rex = re.compile(opt)
+        self.assertTrue(rex.match('am'))
+        self.assertTrue(rex.match('bm'))
+        self.assertFalse(rex.match('xm'))
+        self.assertFalse(rex.match('ax'))
+        self.assertEqual(2, rex.groups)
+        groups = rex.match('am').groups()
+        self.assertEqual(('a', 'm'), groups)