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# -*- coding: utf-8 -*-
"""
pygments.lexers.grammar_notation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Lexers for parser generators.
:copyright: Copyright 2006-2015 by the Pygments team, see AUTHORS.
:license: BSD, see LICENSE for details.
"""
from pygments.lexer import RegexLexer, bygroups
from pygments.token import Punctuation, Text, Comment, Operator, \
Keyword, Name, Literal
__all__ = ['BnfLexer', 'AbnfLexer']
class BnfLexer(RegexLexer):
"""
This lexer is for grammer notations which are similar to
original BNF.
In order to maximize a number of targets of this lexer,
let's decide some designs:
* We don't distinct `Terminal Symbol`.
* We do assume that `NonTerminal Symbol` are always enclosed
with arrow brackets.
* We do assume that `NonTerminal Symbol` may include
any printable characters except arrow brackets and
space (no `spaces`, just space, i.e., ASCII \x020).
This assumption is for `RBNF <http://www.rfc-base.org/txt/rfc-5511.txt>`_.
* We do assume that target notation doesn't support comment.
* We don't distinct any operators and punctuation except
`::=`.
Though these desision making might cause too minimal highlighting
and you might be disappointed, but it is reasonable for us.
.. versionadded:: 2.1
"""
name = 'BNF'
aliases = ['bnf']
filenames = ['*.bnf']
mimetypes = ['text/x-bnf']
tokens = {
'root': [
(r'(<)([ -;=?-~]+)(>)',
bygroups(Punctuation, Name.Class, Punctuation)),
# an only operator
(r'::=', Operator),
# fallback
(r'.', Text),
],
}
class AbnfLexer(RegexLexer):
"""
Lexer for `IETF 7405 ABNF
<http://www.ietf.org/rfc/rfc7405.txt>`_
(Updates `5234 <http://www.ietf.org/rfc/rfc5234.txt>`_)
grammars.
.. versionadded:: 2.1
"""
name = 'ABNF'
aliases = ['abnf']
filenames = ['*.abnf']
mimetypes = ['text/x-abnf']
_core_rules = (
'ALPHA', 'BIT', 'CHAR', 'CR', 'CRLF', 'CTL', 'DIGIT',
'DQUOTE', 'HEXDIG', 'HTAB', 'LF', 'LWSP', 'OCTET',
'SP', 'VCHAR', 'WSP',)
def nonterminal_cb(self, match):
txt = match.group(0)
if txt in self._core_rules:
# Strictly speaking, these are not keyword but
# is called `Core Rule'.
yield match.start(), Keyword, txt
else:
yield match.start(), Name.Class, txt
tokens = {
'root': [
# comment
(r';.*$', Comment.Single),
# quoted
(r'(%[si])?"', Literal, 'quoted-termination'),
# binary (but i have never seen...)
(r'%b[01]+\-[01]+\b', Literal), # range
(r'%b[01]+(\.[01]+)*\b', Literal), # concat
# decimal
(r'%d[0-9]+\-[0-9]+\b', Literal), # range
(r'%d[0-9]+(\.[0-9]+)*\b', Literal), # concat
# hexadecimal
(r'%x[0-9a-fA-F]+\-[0-9a-fA-F]+\b', Literal), # range
(r'%x[0-9a-fA-F]+(\.[0-9a-fA-F]+)*\b', Literal), # concat
# repetition (<a>*<b>element) including nRule
(r'\b[0-9]+\*[0-9]+', Operator),
(r'\b[0-9]+\*', Operator),
(r'\b[0-9]+', Operator),
(r'\*', Operator),
# nonterminals (ALPHA *(ALPHA / DIGIT / "-"))
(r'[a-zA-Z][a-zA-Z0-9-]+\b', nonterminal_cb),
# operators
(r'(=/|=|/)', Operator),
# punctuation
(r'[\[\]()]', Punctuation),
# fallback
(r'.', Text),
],
'quoted-termination': [
# double quote itself in this state, it is as '%x22'.
(r'"', Literal, '#pop'),
(r'.', Literal),
]
}
|
