1 files changed, 152 insertions, 0 deletions
diff --git a/lib/python2.7/lib2to3/fixes/fix_idioms.py b/lib/python2.7/lib2to3/fixes/fix_idioms.py
new file mode 100644
index 0000000..37b6eef
--- /dev/null
+++ b/lib/python2.7/lib2to3/fixes/fix_idioms.py
@@ -0,0 +1,152 @@
+"""Adjust some old Python 2 idioms to their modern counterparts.
+
+* Change some type comparisons to isinstance() calls:
+    type(x) == T -> isinstance(x, T)
+    type(x) is T -> isinstance(x, T)
+    type(x) != T -> not isinstance(x, T)
+    type(x) is not T -> not isinstance(x, T)
+
+* Change "while 1:" into "while True:".
+
+* Change both
+
+    v = list(EXPR)
+    v.sort()
+    foo(v)
+
+and the more general
+
+    v = EXPR
+    v.sort()
+    foo(v)
+
+into
+
+    v = sorted(EXPR)
+    foo(v)
+"""
+# Author: Jacques Frechet, Collin Winter
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import Call, Comma, Name, Node, BlankLine, syms
+
+CMP = "(n='!=' | '==' | 'is' | n=comp_op< 'is' 'not' >)"
+TYPE = "power< 'type' trailer< '(' x=any ')' > >"
+
+class FixIdioms(fixer_base.BaseFix):
+    explicit = True # The user must ask for this fixer
+
+    PATTERN = r"""
+        isinstance=comparison< %s %s T=any >
+        |
+        isinstance=comparison< T=any %s %s >
+        |
+        while_stmt< 'while' while='1' ':' any+ >
+        |
+        sorted=any<
+            any*
+            simple_stmt<
+              expr_stmt< id1=any '='
+                         power< list='list' trailer< '(' (not arglist<any+>) any ')' > >
+              >
+              '\n'
+            >
+            sort=
+            simple_stmt<
+              power< id2=any
+                     trailer< '.' 'sort' > trailer< '(' ')' >
+              >
+              '\n'
+            >
+            next=any*
+        >
+        |
+        sorted=any<
+            any*
+            simple_stmt< expr_stmt< id1=any '=' expr=any > '\n' >
+            sort=
+            simple_stmt<
+              power< id2=any
+                     trailer< '.' 'sort' > trailer< '(' ')' >
+              >
+              '\n'
+            >
+            next=any*
+        >
+    """ % (TYPE, CMP, CMP, TYPE)
+
+    def match(self, node):
+        r = super(FixIdioms, self).match(node)
+        # If we've matched one of the sort/sorted subpatterns above, we
+        # want to reject matches where the initial assignment and the
+        # subsequent .sort() call involve different identifiers.
+        if r and "sorted" in r:
+            if r["id1"] == r["id2"]:
+                return r
+            return None
+        return r
+
+    def transform(self, node, results):
+        if "isinstance" in results:
+            return self.transform_isinstance(node, results)
+        elif "while" in results:
+            return self.transform_while(node, results)
+        elif "sorted" in results:
+            return self.transform_sort(node, results)
+        else:
+            raise RuntimeError("Invalid match")
+
+    def transform_isinstance(self, node, results):
+        x = results["x"].clone() # The thing inside of type()
+        T = results["T"].clone() # The type being compared against
+        x.prefix = u""
+        T.prefix = u" "
+        test = Call(Name(u"isinstance"), [x, Comma(), T])
+        if "n" in results:
+            test.prefix = u" "
+            test = Node(syms.not_test, [Name(u"not"), test])
+        test.prefix = node.prefix
+        return test
+
+    def transform_while(self, node, results):
+        one = results["while"]
+        one.replace(Name(u"True", prefix=one.prefix))
+
+    def transform_sort(self, node, results):
+        sort_stmt = results["sort"]
+        next_stmt = results["next"]
+        list_call = results.get("list")
+        simple_expr = results.get("expr")
+
+        if list_call:
+            list_call.replace(Name(u"sorted", prefix=list_call.prefix))
+        elif simple_expr:
+            new = simple_expr.clone()
+            new.prefix = u""
+            simple_expr.replace(Call(Name(u"sorted"), [new],
+                                     prefix=simple_expr.prefix))
+        else:
+            raise RuntimeError("should not have reached here")
+        sort_stmt.remove()
+
+        btwn = sort_stmt.prefix
+        # Keep any prefix lines between the sort_stmt and the list_call and
+        # shove them right after the sorted() call.
+        if u"\n" in btwn:
+            if next_stmt:
+                # The new prefix should be everything from the sort_stmt's
+                # prefix up to the last newline, then the old prefix after a new
+                # line.
+                prefix_lines = (btwn.rpartition(u"\n")[0], next_stmt[0].prefix)
+                next_stmt[0].prefix = u"\n".join(prefix_lines)
+            else:
+                assert list_call.parent
+                assert list_call.next_sibling is None
+                # Put a blank line after list_call and set its prefix.
+                end_line = BlankLine()
+                list_call.parent.append_child(end_line)
+                assert list_call.next_sibling is end_line
+                # The new prefix should be everything up to the first new line
+                # of sort_stmt's prefix.
+                end_line.prefix = btwn.rpartition(u"\n")[0]