1 files changed, 91 insertions, 0 deletions
diff --git a/lib/python2.7/lib2to3/fixes/fix_map.py b/lib/python2.7/lib2to3/fixes/fix_map.py
new file mode 100644
index 0000000..7a7d0db
--- /dev/null
+++ b/lib/python2.7/lib2to3/fixes/fix_map.py
@@ -0,0 +1,91 @@
+# Copyright 2007 Google, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Fixer that changes map(F, ...) into list(map(F, ...)) unless there
+exists a 'from future_builtins import map' statement in the top-level
+namespace.
+
+As a special case, map(None, X) is changed into list(X).  (This is
+necessary because the semantics are changed in this case -- the new
+map(None, X) is equivalent to [(x,) for x in X].)
+
+We avoid the transformation (except for the special case mentioned
+above) if the map() call is directly contained in iter(<>), list(<>),
+tuple(<>), sorted(<>), ...join(<>), or for V in <>:.
+
+NOTE: This is still not correct if the original code was depending on
+map(F, X, Y, ...) to go on until the longest argument is exhausted,
+substituting None for missing values -- like zip(), it now stops as
+soon as the shortest argument is exhausted.
+"""
+
+# Local imports
+from ..pgen2 import token
+from .. import fixer_base
+from ..fixer_util import Name, Call, ListComp, in_special_context
+from ..pygram import python_symbols as syms
+
+class FixMap(fixer_base.ConditionalFix):
+    BM_compatible = True
+
+    PATTERN = """
+    map_none=power<
+        'map'
+        trailer< '(' arglist< 'None' ',' arg=any [','] > ')' >
+    >
+    |
+    map_lambda=power<
+        'map'
+        trailer<
+            '('
+            arglist<
+                lambdef< 'lambda'
+                         (fp=NAME | vfpdef< '(' fp=NAME ')'> ) ':' xp=any
+                >
+                ','
+                it=any
+            >
+            ')'
+        >
+    >
+    |
+    power<
+        'map' trailer< '(' [arglist=any] ')' >
+    >
+    """
+
+    skip_on = 'future_builtins.map'
+
+    def transform(self, node, results):
+        if self.should_skip(node):
+            return
+
+        if node.parent.type == syms.simple_stmt:
+            self.warning(node, "You should use a for loop here")
+            new = node.clone()
+            new.prefix = u""
+            new = Call(Name(u"list"), [new])
+        elif "map_lambda" in results:
+            new = ListComp(results["xp"].clone(),
+                           results["fp"].clone(),
+                           results["it"].clone())
+        else:
+            if "map_none" in results:
+                new = results["arg"].clone()
+            else:
+                if "arglist" in results:
+                    args = results["arglist"]
+                    if args.type == syms.arglist and \
+                       args.children[0].type == token.NAME and \
+                       args.children[0].value == "None":
+                        self.warning(node, "cannot convert map(None, ...) "
+                                     "with multiple arguments because map() "
+                                     "now truncates to the shortest sequence")
+                        return
+                if in_special_context(node):
+                    return None
+                new = node.clone()
+            new.prefix = u""
+            new = Call(Name(u"list"), [new])
+        new.prefix = node.prefix
+        return new