Add support for Carbon Programming Language (#2362)

AUTHORS

@@ -261,5 +261,6 @@ Other contributors, listed alphabetically, are:
 * Thomas Voss -- Sed lexer
 * Martin Fischer -- WCAG contrast testing
 * Marc Auberer -- Spice lexer
+* Amr Hesham -- Carbon lexer
 
 Many thanks for all contributions!

pygments/lexers/_mapping.py

@@ -71,6 +71,7 @@
     'CadlLexer': ('pygments.lexers.archetype', 'cADL', ('cadl',), ('*.cadl',), ()),
     'CapDLLexer': ('pygments.lexers.esoteric', 'CapDL', ('capdl',), ('*.cdl',), ()),
     'CapnProtoLexer': ('pygments.lexers.capnproto', "Cap'n Proto", ('capnp',), ('*.capnp',), ()),
+    'CarbonLexer': ('pygments.lexers.carbon', 'Carbon', ('carbon',), ('*.carbon',), ('text/x-carbon',)),
     'CbmBasicV2Lexer': ('pygments.lexers.basic', 'CBM BASIC V2', ('cbmbas',), ('*.bas',), ()),
     'CddlLexer': ('pygments.lexers.cddl', 'CDDL', ('cddl',), ('*.cddl',), ('text/x-cddl',)),
     'CeylonLexer': ('pygments.lexers.jvm', 'Ceylon', ('ceylon',), ('*.ceylon',), ('text/x-ceylon',)),

pygments/lexers/carbon.py

@@ -0,0 +1,70 @@
+"""
+    pygments.lexers.carbon
+    ~~~~~~~~~~~~~~~~~~~~~~
+
+    Lexers for the Carbon programming language.
+
+    :copyright: Copyright 2006-2022 by the Pygments team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+import re
+
+from pygments.lexer import RegexLexer, bygroups, words
+from pygments.token import Text, Comment, Operator, Keyword, Name, String, \
+    Number, Punctuation, Whitespace
+
+__all__ = ['CarbonLexer']
+
+
+class CarbonLexer(RegexLexer):
+    """
+    For Carbon source.
+
+    .. versionadded:: 2.15.0
+    """
+    name = 'Carbon'
+    url = 'https://github.com/carbon-language/carbon-lang'
+    filenames = ['*.carbon']
+    aliases = ['carbon']
+    mimetypes = ['text/x-carbon']
+
+    flags = re.MULTILINE | re.DOTALL
+
+    tokens = {
+        'root': [
+            (r'\n', Whitespace),
+            (r'\s+', Whitespace),
+            (r'\\\n', Text),
+            # comments
+            (r'//(.*?)\n', Comment.Single),
+            (r'/(\\\n)?[*](.|\n)*?[*](\\\n)?/', Comment.Multiline),
+            # Declaration
+            (r'(package|import|api|namespace|library)\b', Keyword.Namespace),
+            (r'(abstract|alias|fn|class|interface|let|var|virtual|external|'
+             r'base|addr|extends)\b', Keyword.Declaration),
+            # Keywords
+            (words(('as', 'or', 'not', 'and', 'break', 'continue', 'case',
+                    'default', 'if', 'else', 'destructor', 'for', 'forall',
+                    'while', 'where', 'then', 'in', 'is', 'return',
+                    'returned'), suffix=r'\b'), Keyword),
+            (r'(self)\b', Keyword.Pseudo),
+            (r'(true|false)\b', Keyword.Constant),
+            (r'(auto|bool|string|i8|i16|i32|i64|u8|u16|u32|u64|'
+             r'f8|f16|f32|f64)\b', Keyword.Type),
+            # numeric literals
+            (r'[0-9]*[.][0-9]+', Number.Double),
+            (r'0b[01]+[sl]?', Number.Bin),
+            (r'0o[0-7]+[sl]?', Number.Oct),
+            (r'[0-9]+', Number.Integer),
+            # string literal
+            (r'"(\\.|[^"\\])*"', String),
+            # char literal
+            (r'\'(\\.|[^\'\\])\'', String.Char),
+            # tokens
+            (r'<<=|>>=|<<|>>|<=|>=|\+=|-=|\*=|/=|\%=|\|=|&=|\^=|&&|\|\||&|\||'
+             r'\+\+|--|\%|\^|\~|==|!=|::|[.]{3}|[+\-*/&]|->|=>', Operator),
+            (r'[|<>=!()\[\]{}.,;:\?]', Punctuation),
+            # identifiers
+            (r'[^\W\d]\w*', Name.Other),
+        ]
+    }

tests/examplefiles/carbon/example.carbon

@@ -0,0 +1,19 @@
+package Sorting api;
+
+fn Partition[T: !Comparable & Movable](s : Slice(T)) -> i64 {
+   var i: i64 = -1;
+   for (e: T in s) {
+      ++i;
+      Swap(&s[i], &e);
+   }
+   return i;
+}
+
+fb QuickSort[T: !Comparable & Movable](s : Slice(T)) {
+   if (s.Size() <= 1) {
+       return;
+   }
+   let p: i64 = Partition(s);
+   QuickSort(s[:p - 1]);
+   QuickSort(s[p + 1:]);
+}