Rename @with_template and class Wrapper to @contextmanager and class

ContextManager.  Mark open issues as resolved.

pep-0343.txt

@@ -111,7 +111,7 @@ Motivation and Summary
     example, it was impossible to do this for the opening example.
     The idea was to define the template like this:
 
-        @with_template
+        @contextmanager
         def opening(filename):
             f = open(filename)
             try:
@@ -258,7 +258,7 @@ Generator Decorator
     that makes it possible to use a generator that yields exactly once
     to control a with-statement.  Here's a sketch of such a decorator:
 
-        class Wrapper(object):
+        class ContextManager(object):
 
            def __init__(self, gen):
                self.gen = gen
@@ -285,16 +285,16 @@ Generator Decorator
                    else:
                        raise RuntimeError("generator caught exception")
 
-        def with_template(func):
+        def contextmanager(func):
            def helper(*args, **kwds):
-               return Wrapper(func(*args, **kwds))
+               return ContextManager(func(*args, **kwds))
            return helper
 
     This decorator could be used as follows:
 
-        @with_template
+        @contextmanager
         def opening(filename):
-           f = open(filename) # IOError here is untouched by Wrapper
+           f = open(filename) # IOError is untouched by ContextManager
            try:
                yield f
            finally:
@@ -332,18 +332,20 @@ Optional Extensions
     is entered).
 
     OTOH such mistakes are easily diagnosed; for example, the
-    with_template decorator above raises RuntimeError when the second
+    contextmanager decorator above raises RuntimeError when the second
     with-statement calls f.__enter__() again.
 
-Open Issues
+Resolved Open Issues
 
-    Discussion on python-dev has revealed some open issues.  I list
-    them here, with my preferred resolution and its motivation.  The
-    PEP as currently written reflects this preferred resolution.
+    Discussion on python-dev revealed some open issues.  I list them
+    here, with my preferred resolution and its motivation.  The PEP
+    has been accepted without these being challenged, so the issues
+    are now resolved.
 
-    1. The __exit__() method of the with_template decorator class catches
-       StopIteration and considers it equivalent to re-raising the exception
-       passed to throw().  Is allowing StopIteration right here?
+    1. The __exit__() method of the contextmanager decorator class
+       catches StopIteration and considers it equivalent to re-raising
+       the exception passed to throw().  Is allowing StopIteration
+       right here?
 
        This is so that a generator doing cleanup depending on the
        exception thrown (like the transactional() example below) can
@@ -368,7 +370,7 @@ Examples
     1. A template for ensuring that a lock, acquired at the start of a
        block, is released when the block is left:
 
-        @with_template
+        @contextmanager
         def locking(lock):
             lock.acquire()
             try:
@@ -390,7 +392,7 @@ Examples
     2. A template for opening a file that ensures the file is closed
        when the block is left:
 
-        @with_template
+        @contextmanager
         def opening(filename, mode="r"):
             f = open(filename, mode)
             try:
@@ -407,7 +409,7 @@ Examples
     3. A template for committing or rolling back a database
        transaction:
 
-        @with_template
+        @contextmanager
         def transactional(db):
             db.begin()
             try:
@@ -433,7 +435,7 @@ Examples
 
     5. Redirect stdout temporarily:
 
-        @with_template
+        @contextmanager
         def redirecting_stdout(new_stdout):
             save_stdout = sys.stdout
             sys.stdout = new_stdout
@@ -454,7 +456,7 @@ Examples
 
     6. A variant on opening() that also returns an error condition:
 
-        @with_template
+        @contextmanager
         def opening_w_error(filename, mode="r"):
             try:
                 f = open(filename, mode)
@@ -491,7 +493,7 @@ Examples
 
         import decimal
 
-        @with_template
+        @contextmanager
         def extra_precision(places=2):
             c = decimal.getcontext()
             saved_prec = c.prec
@@ -520,7 +522,7 @@ Examples
 
     9. Here's a more general Decimal-context-switching template:
 
-        @with_template
+        @contextmanager
         def decimal_context(newctx=None):
             oldctx = decimal.getcontext()
             if newctx is None:
@@ -545,7 +547,7 @@ Examples
 
     10. A generic "object-closing" template:
 
-        @with_template
+        @contextmanager
         def closing(obj):
             try:
                 yield obj