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"""
pygments.util
~~~~~~~~~~~~~
Utility functions.
:copyright: Copyright 2006-2024 by the Pygments team, see AUTHORS.
:license: BSD, see LICENSE for details.
"""
import re
from io import TextIOWrapper
split_path_re = re.compile(r'[/\\ ]')
doctype_lookup_re = re.compile(r'''
<!DOCTYPE\s+(
[a-zA-Z_][a-zA-Z0-9]*
(?: \s+ # optional in HTML5
[a-zA-Z_][a-zA-Z0-9]*\s+
"[^"]*")?
)
[^>]*>
''', re.DOTALL | re.MULTILINE | re.VERBOSE)
tag_re = re.compile(r'<(.+?)(\s.*?)?>.*?</.+?>',
re.IGNORECASE | re.DOTALL | re.MULTILINE)
xml_decl_re = re.compile(r'\s*<\?xml[^>]*\?>', re.I)
class ClassNotFound(ValueError):
"""Raised if one of the lookup functions didn't find a matching class."""
class OptionError(Exception):
"""
This exception will be raised by all option processing functions if
the type or value of the argument is not correct.
"""
def get_choice_opt(options, optname, allowed, default=None, normcase=False):
"""
If the key `optname` from the dictionary is not in the sequence
`allowed`, raise an error, otherwise return it.
"""
string = options.get(optname, default)
if normcase:
string = string.lower()
if string not in allowed:
raise OptionError('Value for option {} must be one of {}'.format(optname, ', '.join(map(str, allowed))))
return string
def get_bool_opt(options, optname, default=None):
"""
Intuitively, this is `options.get(optname, default)`, but restricted to
Boolean value. The Booleans can be represented as string, in order to accept
Boolean value from the command line arguments. If the key `optname` is
present in the dictionary `options` and is not associated with a Boolean,
raise an `OptionError`. If it is absent, `default` is returned instead.
The valid string values for ``True`` are ``1``, ``yes``, ``true`` and
``on``, the ones for ``False`` are ``0``, ``no``, ``false`` and ``off``
(matched case-insensitively).
"""
string = options.get(optname, default)
if isinstance(string, bool):
return string
elif isinstance(string, int):
return bool(string)
elif not isinstance(string, str):
raise OptionError(f'Invalid type {string!r} for option {optname}; use '
'1/0, yes/no, true/false, on/off')
elif string.lower() in ('1', 'yes', 'true', 'on'):
return True
elif string.lower() in ('0', 'no', 'false', 'off'):
return False
else:
raise OptionError(f'Invalid value {string!r} for option {optname}; use '
'1/0, yes/no, true/false, on/off')
def get_int_opt(options, optname, default=None):
"""As :func:`get_bool_opt`, but interpret the value as an integer."""
string = options.get(optname, default)
try:
return int(string)
except TypeError:
raise OptionError(f'Invalid type {string!r} for option {optname}; you '
'must give an integer value')
except ValueError:
raise OptionError(f'Invalid value {string!r} for option {optname}; you '
'must give an integer value')
def get_list_opt(options, optname, default=None):
"""
If the key `optname` from the dictionary `options` is a string,
split it at whitespace and return it. If it is already a list
or a tuple, it is returned as a list.
"""
val = options.get(optname, default)
if isinstance(val, str):
return val.split()
elif isinstance(val, (list, tuple)):
return list(val)
else:
raise OptionError(f'Invalid type {val!r} for option {optname}; you '
'must give a list value')
def docstring_headline(obj):
if not obj.__doc__:
return ''
res = []
for line in obj.__doc__.strip().splitlines():
if line.strip():
res.append(" " + line.strip())
else:
break
return ''.join(res).lstrip()
def make_analysator(f):
"""Return a static text analyser function that returns float values."""
def text_analyse(text):
try:
rv = f(text)
except Exception:
return 0.0
if not rv:
return 0.0
try:
return min(1.0, max(0.0, float(rv)))
except (ValueError, TypeError):
return 0.0
text_analyse.__doc__ = f.__doc__
return staticmethod(text_analyse)
def shebang_matches(text, regex):
r"""Check if the given regular expression matches the last part of the
shebang if one exists.
>>> from pygments.util import shebang_matches
>>> shebang_matches('#!/usr/bin/env python', r'python(2\.\d)?')
True
>>> shebang_matches('#!/usr/bin/python2.4', r'python(2\.\d)?')
True
>>> shebang_matches('#!/usr/bin/python-ruby', r'python(2\.\d)?')
False
>>> shebang_matches('#!/usr/bin/python/ruby', r'python(2\.\d)?')
False
>>> shebang_matches('#!/usr/bin/startsomethingwith python',
... r'python(2\.\d)?')
True
It also checks for common windows executable file extensions::
>>> shebang_matches('#!C:\\Python2.4\\Python.exe', r'python(2\.\d)?')
True
Parameters (``'-f'`` or ``'--foo'`` are ignored so ``'perl'`` does
the same as ``'perl -e'``)
Note that this method automatically searches the whole string (eg:
the regular expression is wrapped in ``'^$'``)
"""
index = text.find('\n')
if index >= 0:
first_line = text[:index].lower()
else:
first_line = text.lower()
if first_line.startswith('#!'):
try:
found = [x for x in split_path_re.split(first_line[2:].strip())
if x and not x.startswith('-')][-1]
except IndexError:
return False
regex = re.compile(rf'^{regex}(\.(exe|cmd|bat|bin))?$', re.IGNORECASE)
if regex.search(found) is not None:
return True
return False
def doctype_matches(text, regex):
"""Check if the doctype matches a regular expression (if present).
Note that this method only checks the first part of a DOCTYPE.
eg: 'html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"'
"""
m = doctype_lookup_re.search(text)
if m is None:
return False
doctype = m.group(1)
return re.compile(regex, re.I).match(doctype.strip()) is not None
def html_doctype_matches(text):
"""Check if the file looks like it has a html doctype."""
return doctype_matches(text, r'html')
_looks_like_xml_cache = {}
def looks_like_xml(text):
"""Check if a doctype exists or if we have some tags."""
if xml_decl_re.match(text):
return True
key = hash(text)
try:
return _looks_like_xml_cache[key]
except KeyError:
m = doctype_lookup_re.search(text)
if m is not None:
return True
rv = tag_re.search(text[:1000]) is not None
_looks_like_xml_cache[key] = rv
return rv
def surrogatepair(c):
"""Given a unicode character code with length greater than 16 bits,
return the two 16 bit surrogate pair.
"""
# From example D28 of:
# http://www.unicode.org/book/ch03.pdf
return (0xd7c0 + (c >> 10), (0xdc00 + (c & 0x3ff)))
def format_lines(var_name, seq, raw=False, indent_level=0):
"""Formats a sequence of strings for output."""
lines = []
base_indent = ' ' * indent_level * 4
inner_indent = ' ' * (indent_level + 1) * 4
lines.append(base_indent + var_name + ' = (')
if raw:
# These should be preformatted reprs of, say, tuples.
for i in seq:
lines.append(inner_indent + i + ',')
else:
for i in seq:
# Force use of single quotes
r = repr(i + '"')
lines.append(inner_indent + r[:-2] + r[-1] + ',')
lines.append(base_indent + ')')
return '\n'.join(lines)
def duplicates_removed(it, already_seen=()):
"""
Returns a list with duplicates removed from the iterable `it`.
Order is preserved.
"""
lst = []
seen = set()
for i in it:
if i in seen or i in already_seen:
continue
lst.append(i)
seen.add(i)
return lst
class Future:
"""Generic class to defer some work.
Handled specially in RegexLexerMeta, to support regex string construction at
first use.
"""
def get(self):
raise NotImplementedError
def guess_decode(text):
"""Decode *text* with guessed encoding.
First try UTF-8; this should fail for non-UTF-8 encodings.
Then try the preferred locale encoding.
Fall back to latin-1, which always works.
"""
try:
text = text.decode('utf-8')
return text, 'utf-8'
except UnicodeDecodeError:
try:
import locale
prefencoding = locale.getpreferredencoding()
text = text.decode()
return text, prefencoding
except (UnicodeDecodeError, LookupError):
text = text.decode('latin1')
return text, 'latin1'
def guess_decode_from_terminal(text, term):
"""Decode *text* coming from terminal *term*.
First try the terminal encoding, if given.
Then try UTF-8. Then try the preferred locale encoding.
Fall back to latin-1, which always works.
"""
if getattr(term, 'encoding', None):
try:
text = text.decode(term.encoding)
except UnicodeDecodeError:
pass
else:
return text, term.encoding
return guess_decode(text)
def terminal_encoding(term):
"""Return our best guess of encoding for the given *term*."""
if getattr(term, 'encoding', None):
return term.encoding
import locale
return locale.getpreferredencoding()
class UnclosingTextIOWrapper(TextIOWrapper):
# Don't close underlying buffer on destruction.
def close(self):
self.flush()
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