# -*- coding: utf-8 -*-
"""
    pygments.lexers.rust
    ~~~~~~~~~~~~~~~~~~~~

    Lexers for the Rust language.

    :copyright: Copyright 2006-2019 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', 'rs']
    mimetypes = ['text/rust']

    keyword_types = (
        words(('u8', 'u16', 'u32', 'u64', 'i8', 'i16', 'i32', 'i64',
               'i128', 'u128', 'usize', 'isize', 'f32', 'f64', 'str', 'bool'),
              suffix=r'\b'),
        Keyword.Type)

    builtin_types = (words((
        # Reexported core operators
        'Copy', 'Send', 'Sized', 'Sync',
        'Drop', 'Fn', 'FnMut', 'FnOnce',

        # 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)

    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', 'async', 'await', 'box', 'const', 'crate', 'else',
                'extern', 'for', 'if', 'impl', 'in', 'loop', 'match', 'move',
                'mut', 'pub', 'ref', 'return', 'static', 'super', 'trait',
                'try', '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)),
            keyword_types,
            (r'self\b', Name.Builtin.Pseudo),
            # Prelude (taken from Rust's src/libstd/prelude.rs)
            builtin_types,
            # Path seperators, so types don't catch them.
            (r'::\b', Text),
            # Types in positions.
            (r'(?::|->)', Text, 'typename'),
            # 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'&', Keyword.Pseudo),
            builtin_types,
            keyword_types,
            (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),
        ],
    }
