Re: [Python-Dev] anonymous blocks

[Brian Sabbey]

Guido van Rossum wrote:
@acquire(myLock):
    code
    code
    code
It would certainly solve the problem of which keyword to use! :-) And
I think the syntax isn't even ambiguous -- the trailing colon
distinguishes this from the function decorator syntax. I guess it
would morph '@xxx' into "user-defined-keyword".
How would acquire be defined? I guess it could be this, returning a
function that takes a callable as an argument just like other
decorators:
def acquire(aLock):
   def acquirer(block):
       aLock.acquire()
       try:
           block()
       finally:
           aLock.release()
   return acquirer
and the substitution of
@EXPR:
   CODE
would become something like
def __block():
   CODE
EXPR(__block)
Why not have the block automatically be inserted into acquire's argument 
list?  It would probably get annoying to have to define inner functions 
like that every time one simply wants to use arguments.  For example:

def acquire(block, aLock):
        aLock.acquire()
        try:
                block()
        finally:
                aLock.release()
@acquire(myLock):
        code
        code
        code
Of course, augmenting the argument list in that way would be different 
than the behavior of decorators as they are now.

-Brian
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