Brian Sabbey <[EMAIL PROTECTED]> wrote:
> I would like to get some feedback on a proposal to introduce
> smalltalk/ruby-like "code blocks" to python. Code blocks are, among other
> things, a clean way to solve the "acquire/release" problem [1][2]. This
> proposal also touches on some of the problems PEP 288 [3] deals with.
[...]
My first reaction to the proposal was "ick". Why? Because every time
I've seen a mechanism for modifying the internals of generators
constructed using yield, the syntax has been awful; in my opinion
(whether my opinion means anything is another matter), the syntax you
propose is quite awful, and the functionality you desire does not
require syntax modification to be possible.
Strawman 1: the syntax
def pickled_file(name):
f = open(name, 'r')
l yield pickle.load(f)
^
------
| f.close()
| f = open(name, 'w')
| pickle.dump(l, f)
| f.close()
|
While this is currently a syntax error, it is not clear that an
assignment is happening /at all/, and I don't believe it would be /even
if/ if were documented, and every time someone opened up Python it said
"This is an assignment!" with an example. It looks too magical to me
(and from a guy who had previously proposed 'Some' as the opposite of
'None', that's saying something).
Strawman 2: putting data back into a generator
def pickled_file(name):
f = open(name, 'r')
yield pickle.load(f)
f.close()
f = open(name, 'w')
pickle.dump(l, f)
f.close()
Keep your code, except toss that leading 'l'.
for l in pickled_file('greetings.pickle'):
l.append('hello')
l.append('howdy')
Toss that 'continue l', and your code will work (as long as both the
function and the for are sitting in the same namespace).
Hrm, not good enough? Use a Queue, or use another variable in a
namespace accessable to both your function and your loop.
Strawman 3: there is no strawman 3, but all lists need to have at least
3 items
I'm sorry if this email comes off harsh,
- Josiah
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