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Issue #15096: Drop support for the ur string prefix

This commit is contained in:
Christian Heimes 2012-06-20 11:17:58 +02:00
parent 10c8791978
commit 0b3847de6d
6 changed files with 28 additions and 37 deletions
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14
Doc/reference/lexical_analysis.rst
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@ -401,7 +401,7 @@ String literals are described by the following lexical definitions:
.. productionlist::
stringliteral: [`stringprefix`](`shortstring` | `longstring`)
stringprefix: "r" | "u" | "ur" | "R" | "U" | "UR" | "Ur" | "uR"
stringprefix: "r" | "u" | "R" | "U"
shortstring: "'" `shortstringitem`* "'" | '"' `shortstringitem`* '"'
longstring: "'''" `longstringitem`* "'''" | '"""' `longstringitem`* '"""'
shortstringitem: `shortstringchar` | `stringescapeseq`
@ -444,19 +444,21 @@ must be expressed with escapes.
As of Python 3.3 it is possible again to prefix unicode strings with a
``u`` prefix to simplify maintenance of dual 2.x and 3.x codebases.
Both string and bytes literals may optionally be prefixed with a letter ``'r'``
Bytes literals may optionally be prefixed with a letter ``'r'``
or ``'R'``; such strings are called :dfn:`raw strings` and treat backslashes as
literal characters. As a result, in string literals, ``'\U'`` and ``'\u'``
escapes in raw strings are not treated specially.
escapes in raw strings are not treated specially. Given that Python 2.x's raw
unicode literals behave differently than Python 3.x's the ``'ur'`` syntax
is not supported.
.. versionadded:: 3.3
The ``'rb'`` prefix of raw bytes literals has been added as a synonym
of ``'br'``.
.. versionadded:: 3.3
Support for the unicode legacy literal (``u'value'``) and other
versions were reintroduced to simplify the maintenance of dual
Python 2.x and 3.x codebases. See :pep:`414` for more information.
Support for the unicode legacy literal (``u'value'``) was reintroduced
to simplify the maintenance of dual Python 2.x and 3.x codebases.
See :pep:`414` for more information.
In triple-quoted strings, unescaped newlines and quotes are allowed (and are
retained), except that three unescaped quotes in a row terminate the string. (A

9
Lib/test/test_strlit.py
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@ -123,6 +123,15 @@ class TestLiterals(unittest.TestCase):
self.assertRaises(SyntaxError, eval, """ rrb'' """)
self.assertRaises(SyntaxError, eval, """ rbb'' """)
def test_eval_str_u(self):
self.assertEqual(eval(""" u'x' """), 'x')
self.assertEqual(eval(""" U'\u00e4' """), 'ä')
self.assertEqual(eval(""" u'\N{LATIN SMALL LETTER A WITH DIAERESIS}' """), 'ä')
self.assertRaises(SyntaxError, eval, """ ur'' """)
self.assertRaises(SyntaxError, eval, """ ru'' """)
self.assertRaises(SyntaxError, eval, """ bu'' """)
self.assertRaises(SyntaxError, eval, """ ub'' """)
def check_encoding(self, encoding, extra=""):
modname = "xx_" + encoding.replace("-", "_")
fn = os.path.join(self.tmpdir, modname + ".py")

22
Lib/test/test_tokenize.py
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@ -299,24 +299,6 @@ String literals
STRING 'u"abc"' (1, 0) (1, 6)
OP '+' (1, 7) (1, 8)
STRING 'U"abc"' (1, 9) (1, 15)
>>> dump_tokens("ur'abc' + uR'abc' + Ur'abc' + UR'abc'")
ENCODING 'utf-8' (0, 0) (0, 0)
STRING "ur'abc'" (1, 0) (1, 7)
OP '+' (1, 8) (1, 9)
STRING "uR'abc'" (1, 10) (1, 17)
OP '+' (1, 18) (1, 19)
STRING "Ur'abc'" (1, 20) (1, 27)
OP '+' (1, 28) (1, 29)
STRING "UR'abc'" (1, 30) (1, 37)
>>> dump_tokens('ur"abc" + uR"abc" + Ur"abc" + UR"abc"')
ENCODING 'utf-8' (0, 0) (0, 0)
STRING 'ur"abc"' (1, 0) (1, 7)
OP '+' (1, 8) (1, 9)
STRING 'uR"abc"' (1, 10) (1, 17)
OP '+' (1, 18) (1, 19)
STRING 'Ur"abc"' (1, 20) (1, 27)
OP '+' (1, 28) (1, 29)
STRING 'UR"abc"' (1, 30) (1, 37)
>>> dump_tokens("b'abc' + B'abc'")
ENCODING 'utf-8' (0, 0) (0, 0)
@ -642,7 +624,7 @@ Non-ascii identifiers
Legacy unicode literals:
>>> dump_tokens("Örter = u'places'\\ngrün = UR'green'")
>>> dump_tokens("Örter = u'places'\\ngrün = U'green'")
ENCODING 'utf-8' (0, 0) (0, 0)
NAME 'Örter' (1, 0) (1, 5)
OP '=' (1, 6) (1, 7)
@ -650,7 +632,7 @@ Legacy unicode literals:
NEWLINE '\\n' (1, 17) (1, 18)
NAME 'grün' (2, 0) (2, 4)
OP '=' (2, 5) (2, 6)
STRING "UR'green'" (2, 7) (2, 16)
STRING "U'green'" (2, 7) (2, 15)
"""
from test import support

12
Lib/tokenize.py
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@ -127,7 +127,7 @@ Floatnumber = group(Pointfloat, Expfloat)
Imagnumber = group(r'[0-9]+[jJ]', Floatnumber + r'[jJ]')
Number = group(Imagnumber, Floatnumber, Intnumber)
StringPrefix = r'(?:[uUbB][rR]?|[rR][bB]?)?'
StringPrefix = r'(?:[bB][rR]?|[rR][bB]?|[uU])?'
# Tail end of ' string.
Single = r"[^'\\]*(?:\\.[^'\\]*)*'"
@ -183,12 +183,8 @@ endpats = {"'": Single, '"': Double,
"rB'''": Single3, 'rB"""': Double3,
"RB'''": Single3, 'RB"""': Double3,
"u'''": Single3, 'u"""': Double3,
"ur'''": Single3, 'ur"""': Double3,
"R'''": Single3, 'R"""': Double3,
"U'''": Single3, 'U"""': Double3,
"uR'''": Single3, 'uR"""': Double3,
"Ur'''": Single3, 'Ur"""': Double3,
"UR'''": Single3, 'UR"""': Double3,
'r': None, 'R': None, 'b': None, 'B': None,
'u': None, 'U': None}
@ -201,8 +197,7 @@ for t in ("'''", '"""',
"rb'''", 'rb"""', "rB'''", 'rB"""',
"Rb'''", 'Rb"""', "RB'''", 'RB"""',
"u'''", 'u"""', "U'''", 'U"""',
"ur'''", 'ur"""', "Ur'''", 'Ur"""',
"uR'''", 'uR"""', "UR'''", 'UR"""'):
):
triple_quoted[t] = t
single_quoted = {}
for t in ("'", '"',
@ -213,8 +208,7 @@ for t in ("'", '"',
"rb'", 'rb"', "rB'", 'rB"',
"Rb'", 'Rb"', "RB'", 'RB"' ,
"u'", 'u"', "U'", 'U"',
"ur'", 'ur"', "Ur'", 'Ur"',
"uR'", 'uR"', "UR'", 'UR"' ):
):
single_quoted[t] = t
tabsize = 8

3
Misc/NEWS
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@ -10,6 +10,9 @@ What's New in Python 3.3.0 Beta 1?
Core and Builtins
-----------------
- Issue #15096: Removed support for ur'' as the raw notation isn't
compatible with Python 2.x's raw unicode strings.
- Issue #13783: Generator objects now use the identifier APIs internally
- Issue #14874: Restore charmap decoding speed to pre-PEP 393 levels.

5
Parser/tokenizer.c
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@ -1412,7 +1412,7 @@ tok_get(register struct tok_state *tok, char **p_start, char **p_end)
/* Identifier (most frequent token!) */
nonascii = 0;
if (is_potential_identifier_start(c)) {
/* Process b"", r"", u"", br"", rb"" and ur"" */
/* Process b"", r"", u"", br"" and rb"" */
int saw_b = 0, saw_r = 0, saw_u = 0;
while (1) {
if (!(saw_b || saw_u) && (c == 'b' || c == 'B'))
@ -1421,7 +1421,8 @@ tok_get(register struct tok_state *tok, char **p_start, char **p_end)
want to support it in arbitrary order like byte literals. */
else if (!(saw_b || saw_u || saw_r) && (c == 'u' || c == 'U'))
saw_u = 1;
else if (!saw_r && (c == 'r' || c == 'R'))
/* ur"" and ru"" are not supported */
else if (!(saw_r || saw_u) && (c == 'r' || c == 'R'))
saw_r = 1;
else
break;