117 lines
2.9 KiB
Python
117 lines
2.9 KiB
Python
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from __future__ import unicode_literals
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import sys
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import stringprep
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import unicodedata
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class StringPrepError(UnicodeError):
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pass
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def to_unicode(data):
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if sys.version_info < (3, 0):
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return unicode(data)
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else:
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return str(data)
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def b1_mapping(char):
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return '' if stringprep.in_table_c12(char) else None
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def c12_mapping(char):
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return ' ' if stringprep.in_table_c12(char) else None
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def map_input(data, tables=None):
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"""
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Each character in the input stream MUST be checked against
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a mapping table.
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"""
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result = []
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for char in data:
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replacement = None
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for mapping in tables:
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replacement = mapping(char)
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if replacement is not None:
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break
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if replacement is None:
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replacement = char
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result.append(replacement)
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return ''.join(result)
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def normalize(data, nfkc=True):
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"""
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A profile can specify one of two options for Unicode normalization:
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- no normalization
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- Unicode normalization with form KC
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"""
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if nfkc:
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data = unicodedata.normalize('NFKC', data)
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return data
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def prohibit_output(data, tables=None):
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"""
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Before the text can be emitted, it MUST be checked for prohibited
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code points.
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"""
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for char in data:
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for check in tables:
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if check(char):
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raise StringPrepError("Prohibited code point: %s" % char)
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def check_bidi(data):
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"""
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1) The characters in section 5.8 MUST be prohibited.
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2) If a string contains any RandALCat character, the string MUST NOT
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contain any LCat character.
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3) If a string contains any RandALCat character, a RandALCat
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character MUST be the first character of the string, and a
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RandALCat character MUST be the last character of the string.
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"""
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has_lcat = False
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has_randal = False
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for c in data:
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if stringprep.in_table_c8(c):
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raise StringPrepError("BIDI violation: seciton 6 (1)")
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if stringprep.in_table_d1(c):
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has_randal = True
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elif stringprep.in_table_d2(c):
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has_lcat = True
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if has_randal and has_lcat:
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raise StringPrepError("BIDI violation: section 6 (2)")
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first_randal = stringprep.in_table_d1(data[0])
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last_randal = stringprep.in_table_d1(data[-1])
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if has_randal and not (first_randal and last_randal):
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raise StringPrepError("BIDI violation: section 6 (3)")
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def create(nfkc=True, bidi=True, mappings=None,
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prohibited=None, unassigned=None):
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def profile(data, query=False):
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try:
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data = to_unicode(data)
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except UnicodeError:
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raise StringPrepError
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data = map_input(data, mappings)
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data = normalize(data, nfkc)
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prohibit_output(data, prohibited)
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if bidi:
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check_bidi(data)
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if query and unassigned:
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check_unassigned(data, unassigned)
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return data
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return profile
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