Import lib2to3.

1 files changed, 109 insertions, 0 deletions

diff --git a/Lib/lib2to3/fixes/fix_has_key.py b/Lib/lib2to3/fixes/fix_has_key.py
new file mode 100644
index 0000000..ea7bfc5
--- /dev/null
+++ b/Lib/lib2to3/fixes/fix_has_key.py
@@ -0,0 +1,109 @@
+# 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