Re: For review: PEP 343: Anonymous Block Redux and Generator Enhancements

Andrew Dalke wrote: 
def foo():
    with locking(someMutex)
        with opening(readFilename) as input
            with opening(writeFilename) as output
                ...



Nothing in Python ends at the end of the current block.
They only end with the scope exits.  The order of deletion
is not defined, and you would change that as well.

There's no change in order of deletion, it's just about defining the order of calls to __exit__, and they are exactly the same. As far as I know, PEP343 has nothing to do with order of deletion, which is still implementation-dependant. It's not a constructor/destructor thing like in C++ RAII, but __enter__/__exit__.

But yes, it creates a precedent by creating a statement affecting the end of the current indentation block. But that's what this PEP is all about...

Your approach wouldn't allow the following

No, I said making the ':' *optional*. I totally agree supporting ':' is useful.

If the number of blocks is a problem it wouldn't be that
hard to do

with multi( locking(someMutex),
            opening(readFilename),
            opening(writeFilename) ) as _, input, output:
  ...


True.  But does it look as good?  Particularly the _ part?

Regards,
Nicolas
.

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