[Python-Dev] Extended Function syntax

[Samuele Pedroni]

From: "Samuele Pedroni" <pedronis@bluewin.ch>
> From: "Guido van Rossum" <guido@python.org>
> > I think so far I've been thinking mostly about fitting my proposal on
> > all edges (that's where my discussion of the thunk's scope comes
> > from).  Maybe I should try to focus more on collecting real-world
> > examples that are asking for syntactic support, and then try to look
> > for the simplest way to support most of them.
>
> yes, real-world examples would be good.

In particular real-world examples, not covered by 'for' and generators or
'with'*, that need rebinding the surrounding function locals and/or non-local
return.

[Just for fun,  on the hackery/contrived side of things, we would finally get a
version of Paul Graham's accumulator generator
   http://www.paulgraham.com/accgen.html
with mostly lisp-y length:

def accmaker(n):
  do acc = (lambda x:x): (i):
     n += i
     value n # ! not 'return', that would be a non-local return
  return acc

]

*

with <expr>:
 <suite>

would be possibly sugar for:

_x = <expr>
_x.__enter__()
try:
  <suite>
finally:
  _x.__exit__()

OR:

_x = <expr>
_x.__enter__()
try:
  try:
   <suite>
  except  getattr(_x,'__excepts__',()),_e:
    _x.__except__(_e)
finally:
  _x.__exit__()