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authorMartin v. Löwis <martin@v.loewis.de>2008-03-19 05:04:44 +0000
committerMartin v. Löwis <martin@v.loewis.de>2008-03-19 05:04:44 +0000
commit8fe370611c6e6fc8804e2419b8705abdb83c1393 (patch)
tree0a62443b693476e7edf5d98a6f7e47d1c12b5f7a /Lib/lib2to3/fixes/fix_has_key.py
parent6b727f38b9defd0c6de7044f727e55135361ee74 (diff)
downloadcpython-8fe370611c6e6fc8804e2419b8705abdb83c1393.tar.gz
Merged revisions 61596-61597 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk ........ r61596 | martin.v.loewis | 2008-03-18 23:43:46 -0500 (Di, 18 Mär 2008) | 2 lines Import lib2to3. ........ r61597 | martin.v.loewis | 2008-03-18 23:58:04 -0500 (Di, 18 Mär 2008) | 3 lines Initialized merge tracking via "svnmerge" with revisions "1-61595" from svn+ssh://pythondev@svn.python.org/sandbox/trunk/2to3/lib2to3 ........
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diff --git a/Lib/lib2to3/fixes/fix_has_key.py b/Lib/lib2to3/fixes/fix_has_key.py
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+# Copyright 2006 Google, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Fixer for has_key().
+
+Calls to .has_key() methods are expressed in terms of the 'in'
+operator:
+
+ d.has_key(k) -> k in d
+
+CAVEATS:
+1) While the primary target of this fixer is dict.has_key(), the
+ fixer will change any has_key() method call, regardless of its
+ class.
+
+2) Cases like this will not be converted:
+
+ m = d.has_key
+ if m(k):
+ ...
+
+ Only *calls* to has_key() are converted. While it is possible to
+ convert the above to something like
+
+ m = d.__contains__
+ if m(k):
+ ...
+
+ this is currently not done.
+"""
+
+# Local imports
+from .. import pytree
+from ..pgen2 import token
+from . import basefix
+from .util import Name
+
+
+class FixHasKey(basefix.BaseFix):
+
+ PATTERN = """
+ anchor=power<
+ before=any+
+ trailer< '.' 'has_key' >
+ trailer<
+ '('
+ ( not(arglist | argument<any '=' any>) arg=any
+ | arglist<(not argument<any '=' any>) arg=any ','>
+ )
+ ')'
+ >
+ after=any*
+ >
+ |
+ negation=not_test<
+ 'not'
+ anchor=power<
+ before=any+
+ trailer< '.' 'has_key' >
+ trailer<
+ '('
+ ( not(arglist | argument<any '=' any>) arg=any
+ | arglist<(not argument<any '=' any>) arg=any ','>
+ )
+ ')'
+ >
+ >
+ >
+ """
+
+ def transform(self, node, results):
+ assert results
+ syms = self.syms
+ if (node.parent.type == syms.not_test and
+ self.pattern.match(node.parent)):
+ # Don't transform a node matching the first alternative of the
+ # pattern when its parent matches the second alternative
+ return None
+ negation = results.get("negation")
+ anchor = results["anchor"]
+ prefix = node.get_prefix()
+ before = [n.clone() for n in results["before"]]
+ arg = results["arg"].clone()
+ after = results.get("after")
+ if after:
+ after = [n.clone() for n in after]
+ if arg.type in (syms.comparison, syms.not_test, syms.and_test,
+ syms.or_test, syms.test, syms.lambdef, syms.argument):
+ arg = self.parenthesize(arg)
+ if len(before) == 1:
+ before = before[0]
+ else:
+ before = pytree.Node(syms.power, before)
+ before.set_prefix(" ")
+ n_op = Name("in", prefix=" ")
+ if negation:
+ n_not = Name("not", prefix=" ")
+ n_op = pytree.Node(syms.comp_op, (n_not, n_op))
+ new = pytree.Node(syms.comparison, (arg, n_op, before))
+ if after:
+ new = self.parenthesize(new)
+ new = pytree.Node(syms.power, (new,) + tuple(after))
+ if node.parent.type in (syms.comparison, syms.expr, syms.xor_expr,
+ syms.and_expr, syms.shift_expr,
+ syms.arith_expr, syms.term,
+ syms.factor, syms.power):
+ new = self.parenthesize(new)
+ new.set_prefix(prefix)
+ return new