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, 209 insertions, 0 deletions

diff --git a/pygments/lexers/rust.py b/pygments/lexers/rust.py
new file mode 100644
index 00000000..d3d98ee8
--- /dev/null
+++ b/pygments/lexers/rust.py
@@ -0,0 +1,209 @@
+# -*- coding: utf-8 -*-
+"""
+    pygments.lexers.rust
+    ~~~~~~~~~~~~~~~~~~~~
+
+    Lexers for the Rust language.
+
+    :copyright: Copyright 2006-2015 by the Pygments team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+from pygments.lexer import RegexLexer, include, bygroups, words, default
+from pygments.token import Text, Comment, Operator, Keyword, Name, String, \
+    Number, Punctuation, Whitespace
+
+__all__ = ['RustLexer']
+
+
+class RustLexer(RegexLexer):
+    """
+    Lexer for the Rust programming language (version 1.10).
+
+    .. versionadded:: 1.6
+    """
+    name = 'Rust'
+    filenames = ['*.rs', '*.rs.in']
+    aliases = ['rust']
+    mimetypes = ['text/rust']
+
+    tokens = {
+        'root': [
+            # rust allows a file to start with a shebang, but if the first line
+            # starts with #![ then it’s not a shebang but a crate attribute.
+            (r'#![^[\r\n].*$', Comment.Preproc),
+            default('base'),
+        ],
+        'base': [
+            # Whitespace and Comments
+            (r'\n', Whitespace),
+            (r'\s+', Whitespace),
+            (r'//!.*?\n', String.Doc),
+            (r'///(\n|[^/].*?\n)', String.Doc),
+            (r'//(.*?)\n', Comment.Single),
+            (r'/\*\*(\n|[^/*])', String.Doc, 'doccomment'),
+            (r'/\*!', String.Doc, 'doccomment'),
+            (r'/\*', Comment.Multiline, 'comment'),
+
+            # Macro parameters
+            (r"""\$([a-zA-Z_]\w*|\(,?|\),?|,?)""", Comment.Preproc),
+            # Keywords
+            (words((
+                'as', 'box', 'const', 'crate', 'else', 'extern',
+                'for', 'if', 'impl', 'in', 'loop', 'match', 'move',
+                'mut', 'pub', 'ref', 'return', 'static', 'super',
+                'trait', 'unsafe', 'use', 'where', 'while'), suffix=r'\b'),
+             Keyword),
+            (words(('abstract', 'alignof', 'become', 'do', 'final', 'macro',
+                    'offsetof', 'override', 'priv', 'proc', 'pure', 'sizeof',
+                    'typeof', 'unsized', 'virtual', 'yield'), suffix=r'\b'),
+             Keyword.Reserved),
+            (r'(true|false)\b', Keyword.Constant),
+            (r'mod\b', Keyword, 'modname'),
+            (r'let\b', Keyword.Declaration),
+            (r'fn\b', Keyword, 'funcname'),
+            (r'(struct|enum|type|union)\b', Keyword, 'typename'),
+            (r'(default)(\s+)(type|fn)\b', bygroups(Keyword, Text, Keyword)),
+            (words(('u8', 'u16', 'u32', 'u64', 'i8', 'i16', 'i32', 'i64', 'usize',
+                    'isize', 'f32', 'f64', 'str', 'bool'), suffix=r'\b'),
+             Keyword.Type),
+            (r'self\b', Name.Builtin.Pseudo),
+            # Prelude (taken from Rust’s src/libstd/prelude.rs)
+            (words((
+                # Reexported core operators
+                'Copy', 'Send', 'Sized', 'Sync',
+                'Drop', 'Fn', 'FnMut', 'FnOnce',
+
+                # Reexported functions
+                'drop',
+
+                # Reexported types and traits
+                'Box',
+                'ToOwned',
+                'Clone',
+                'PartialEq', 'PartialOrd', 'Eq', 'Ord',
+                'AsRef', 'AsMut', 'Into', 'From',
+                'Default',
+                'Iterator', 'Extend', 'IntoIterator',
+                'DoubleEndedIterator', 'ExactSizeIterator',
+                'Option',
+                'Some', 'None',
+                'Result',
+                'Ok', 'Err',
+                'SliceConcatExt',
+                'String', 'ToString',
+                'Vec'), suffix=r'\b'),
+             Name.Builtin),
+            # Labels
+            (r'(break|continue)(\s*)(\'[A-Za-z_]\w*)?',
+             bygroups(Keyword, Text.Whitespace, Name.Label)),
+            # Character Literal
+            (r"""'(\\['"\\nrt]|\\x[0-7][0-9a-fA-F]|\\0"""
+             r"""|\\u\{[0-9a-fA-F]{1,6}\}|.)'""",
+             String.Char),
+            (r"""b'(\\['"\\nrt]|\\x[0-9a-fA-F]{2}|\\0"""
+             r"""|\\u\{[0-9a-fA-F]{1,6}\}|.)'""",
+             String.Char),
+            # Binary Literal
+            (r'0b[01_]+', Number.Bin, 'number_lit'),
+            # Octal Literal
+            (r'0o[0-7_]+', Number.Oct, 'number_lit'),
+            # Hexadecimal Literal
+            (r'0[xX][0-9a-fA-F_]+', Number.Hex, 'number_lit'),
+            # Decimal Literal
+            (r'[0-9][0-9_]*(\.[0-9_]+[eE][+\-]?[0-9_]+|'
+             r'\.[0-9_]*(?!\.)|[eE][+\-]?[0-9_]+)', Number.Float, 'number_lit'),
+            (r'[0-9][0-9_]*', Number.Integer, 'number_lit'),
+            # String Literal
+            (r'b"', String, 'bytestring'),
+            (r'"', String, 'string'),
+            (r'b?r(#*)".*?"\1', String),
+
+            # Lifetime
+            (r"""'static""", Name.Builtin),
+            (r"""'[a-zA-Z_]\w*""", Name.Attribute),
+
+            # Operators and Punctuation
+            (r'[{}()\[\],.;]', Punctuation),
+            (r'[+\-*/%&|<>^!~@=:?]', Operator),
+
+            # Identifier
+            (r'[a-zA-Z_]\w*', Name),
+
+            # Attributes
+            (r'#!?\[', Comment.Preproc, 'attribute['),
+            # Macros
+            (r'([A-Za-z_]\w*)(!)(\s*)([A-Za-z_]\w*)?(\s*)(\{)',
+             bygroups(Comment.Preproc, Punctuation, Whitespace, Name,
+                      Whitespace, Punctuation), 'macro{'),
+            (r'([A-Za-z_]\w*)(!)(\s*)([A-Za-z_]\w*)?(\()',
+             bygroups(Comment.Preproc, Punctuation, Whitespace, Name,
+                      Punctuation), 'macro('),
+        ],
+        'comment': [
+            (r'[^*/]+', Comment.Multiline),
+            (r'/\*', Comment.Multiline, '#push'),
+            (r'\*/', Comment.Multiline, '#pop'),
+            (r'[*/]', Comment.Multiline),
+        ],
+        'doccomment': [
+            (r'[^*/]+', String.Doc),
+            (r'/\*', String.Doc, '#push'),
+            (r'\*/', String.Doc, '#pop'),
+            (r'[*/]', String.Doc),
+        ],
+        'modname': [
+            (r'\s+', Text),
+            (r'[a-zA-Z_]\w*', Name.Namespace, '#pop'),
+            default('#pop'),
+        ],
+        'funcname': [
+            (r'\s+', Text),
+            (r'[a-zA-Z_]\w*', Name.Function, '#pop'),
+            default('#pop'),
+        ],
+        'typename': [
+            (r'\s+', Text),
+            (r'[a-zA-Z_]\w*', Name.Class, '#pop'),
+            default('#pop'),
+        ],
+        'number_lit': [
+            (r'[ui](8|16|32|64|size)', Keyword, '#pop'),
+            (r'f(32|64)', Keyword, '#pop'),
+            default('#pop'),
+        ],
+        'string': [
+            (r'"', String, '#pop'),
+            (r"""\\['"\\nrt]|\\x[0-7][0-9a-fA-F]|\\0"""
+             r"""|\\u\{[0-9a-fA-F]{1,6}\}""", String.Escape),
+            (r'[^\\"]+', String),
+            (r'\\', String),
+        ],
+        'bytestring': [
+            (r"""\\x[89a-fA-F][0-9a-fA-F]""", String.Escape),
+            include('string'),
+        ],
+        'macro{': [
+            (r'\{', Operator, '#push'),
+            (r'\}', Operator, '#pop'),
+        ],
+        'macro(': [
+            (r'\(', Operator, '#push'),
+            (r'\)', Operator, '#pop'),
+        ],
+        'attribute_common': [
+            (r'"', String, 'string'),
+            (r'\[', Comment.Preproc, 'attribute['),
+            (r'\(', Comment.Preproc, 'attribute('),
+        ],
+        'attribute[': [
+            include('attribute_common'),
+            (r'\];?', Comment.Preproc, '#pop'),
+            (r'[^"\]]+', Comment.Preproc),
+        ],
+        'attribute(': [
+            include('attribute_common'),
+            (r'\);?', Comment.Preproc, '#pop'),
+            (r'[^")]+', Comment.Preproc),
+        ],
+    }