March Liu wrote: > lambda key word may remove from CPython 3.0. Maybe we can replace it > by the other way as List Comprehensions, funcation Factory...
I like to encourage people who come from a functional background to use list comprehensions instead of lambda when possible. I'm not sure that lambda should go away, but I do wonder if map, filter and reduce shouldn't be removed from builtins to more strongly encourage the use of list comprehensions or generator expressions instead. > 2005/5/7, Travis Watkins <[EMAIL PROTECTED]>: > > On 5/7/05, PhiHo Hoang <[EMAIL PROTECTED]> wrote: <snip> > > > >>> def make_inc(n): > > > ... return lambda x : x + n > > > ... > > > >>> f = make_inc(100) > > > >>> f(1) > > > IronPython.Objects.PythonNameError: name 'n' is not defined <snip> > > That works on CPython so I'd say it's a bug. As Travis says, the right presumption is that this is a bug especially since this works in recent versions of CPython. IronPython is behaving like CPython 2.1 and earlier by not supporting nested scopes. Here's this same example on CPython-2.0. Notice that it behaves just like IronPython. Python 2.0.1 (#18, Jun 22 2001, 02:26:03) [MSC 32 bit (Intel)] on win32 Type "copyright", "credits" or "license" for more information. >>> def make_inc(n): ... return lambda x: x + n ... >>> f = make_inc(100) >>> f(1) Traceback (most recent call last): File "<stdin>", line 1, in ? File "<stdin>", line 2, in <lambda> NameError: There is no variable named 'n' Today, IronPython is trying to be somewhere between Python 2.3 and 2.4 in features. The goal for the 1.0 release is to be fully compatible with Python 2.4. Therefore, even though this behavior does match an earlier version of CPython, it is a bug since it doesn't match either of our two target versions. This will take some work to fix so it might be a few releases before we get nested scopes properly working in IronPython. Thanks - Jim _______________________________________________ users-ironpython.com mailing list users-ironpython.com@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com
