[Python-checkins] r65981 - in sandbox/trunk/2to3: README lib2to3/fixes/fix_paren.py lib2to3/tests/test_fixers.py

[benjamin.peterson]

Author: benjamin.peterson
Date: Fri Aug 22 22:41:30 2008
New Revision: 65981

Log:
add a fixer to add parenthese for list and gen comps #2367

Added:
   sandbox/trunk/2to3/lib2to3/fixes/fix_paren.py   (contents, props changed)
Modified:
   sandbox/trunk/2to3/README
   sandbox/trunk/2to3/lib2to3/tests/test_fixers.py

Modified: sandbox/trunk/2to3/README
==============================================================================
--- sandbox/trunk/2to3/README	(original)
+++ sandbox/trunk/2to3/README	Fri Aug 22 22:41:30 2008
@@ -90,6 +90,9 @@
 
 * **fix_numliterals** - tweak certain numeric literals to be 3.0-compliant.
 
+* **fix_paren** - Add parentheses to places where they are needed in list
+    comprehensions and generator expressions.
+
 * **fix_print** - convert "print" statements to print() function calls.
 
 * **fix_raise** - convert "raise" statements to Python 3 syntax (PEP 3109).

Added: sandbox/trunk/2to3/lib2to3/fixes/fix_paren.py
==============================================================================
--- (empty file)
+++ sandbox/trunk/2to3/lib2to3/fixes/fix_paren.py	Fri Aug 22 22:41:30 2008
@@ -0,0 +1,42 @@
+"""Fixer that addes parentheses where they are required
+
+This converts ``[x for x in 1, 2]`` to ``[x for x in (1, 2)]``."""
+
+# By Taek Joo Kim and Benjamin Peterson
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import LParen, RParen
+
+# XXX This doesn't support nested for loops like [x for x in 1, 2 for x in 1, 2]
+class FixParen(fixer_base.BaseFix):
+    PATTERN = """
+        atom< ('[' | '(')
+            (listmaker< any
+                comp_for<
+                    'for' NAME 'in'
+                    target=testlist_safe< any (',' any)+ [',']
+                     >
+                    [any]
+                >
+            >
+            |
+            testlist_gexp< any
+                comp_for<
+                    'for' NAME 'in'
+                    target=testlist_safe< any (',' any)+ [',']
+                     >
+                    [any]
+                >
+            >)
+        (']' | ')') >
+    """
+
+    def transform(self, node, results):
+        target = results["target"]
+
+        lparen = LParen()
+        lparen.set_prefix(target.get_prefix())
+        target.set_prefix("") # Make it hug the parentheses
+        target.insert_child(0, lparen)
+        target.append_child(RParen())

Modified: sandbox/trunk/2to3/lib2to3/tests/test_fixers.py
==============================================================================
--- sandbox/trunk/2to3/lib2to3/tests/test_fixers.py	(original)
+++ sandbox/trunk/2to3/lib2to3/tests/test_fixers.py	Fri Aug 22 22:41:30 2008
@@ -3377,6 +3377,65 @@
         self.check(b, a)
 
 
+class Test_paren(FixerTestCase):
+    fixer = "paren"
+
+    def test_0(self):
+        b = """[i for i in 1, 2 ]"""
+        a = """[i for i in (1, 2) ]"""
+        self.check(b, a)
+
+    def test_1(self):
+        b = """[i for i in 1, 2, ]"""
+        a = """[i for i in (1, 2,) ]"""
+        self.check(b, a)
+
+    def test_2(self):
+        b = """[i for i  in     1, 2 ]"""
+        a = """[i for i  in     (1, 2) ]"""
+        self.check(b, a)
+
+    def test_3(self):
+        b = """[i for i in 1, 2 if i]"""
+        a = """[i for i in (1, 2) if i]"""
+        self.check(b, a)
+
+    def test_4(self):
+        b = """[i for i in 1,    2    ]"""
+        a = """[i for i in (1,    2)    ]"""
+        self.check(b, a)
+
+    def test_5(self):
+        b = """(i for i in 1, 2)"""
+        a = """(i for i in (1, 2))"""
+        self.check(b, a)
+
+    def test_6(self):
+        b = """(i for i in 1   ,2   if i)"""
+        a = """(i for i in (1   ,2)   if i)"""
+        self.check(b, a)
+
+    def test_unchanged_0(self):
+        s = """[i for i in (1, 2)]"""
+        self.unchanged(s)
+
+    def test_unchanged_1(self):
+        s = """[i for i in foo()]"""
+        self.unchanged(s)
+
+    def test_unchanged_2(self):
+        s = """[i for i in (1, 2) if nothing]"""
+        self.unchanged(s)
+
+    def test_unchanged_3(self):
+        s = """(i for i in (1, 2))"""
+        self.unchanged(s)
+
+    def test_unchanged_4(self):
+        s = """[i for i in m]"""
+        self.unchanged(s)
+
+
 if __name__ == "__main__":
     import __main__
     support.run_all_tests(__main__)