extending the break statement

[Michele Simionato]

Is there a way of "ending" a module? I would like something like this:

  # mod.py
  print 'something here'
  end() # some mysterious function
  print 'you should not get here'

  # main.py
  import mod
  print 'it works'

I cannot use 'sys.exit' in place of ``end()``, since it would exit from 
the whole program and the line 'it works' would not be printed. 
I know that I can modify the main program to catch the SystemExit
exception:


# main.py
try: 
  import mod
except SystemExit: 
  pass
print 'it works'

but I find it really ugly, since I am forced to change by hand 
all the scripts importing 'mod'. Moreover, I am abusing ``SystemExit``;
I should add instead a new built-in exception ``EndModule``, but this 
requires even more lines of code for something that should be trivial.

On the other hand, I don't like the ``if 0:`` option, i.e. writing ``mod.py`` 
in the form

  # mod.py
  print 'something here'
  end() # some mysterious function
  if 0:
      print 'you should not get here'

since it requires re-indenting by hand the (potentially long) block
of code to be commented out. Yes, I know about C-c->, but honestly
it is a PITA. Typically, I would like to comment out portions of
experimental code during debugging; that code will enter in the final 
program at the end, so I must indent and re-indent it until it works 
(which means lots of times).

More in general, one could think of an ``end()`` function with the ability of
stopping the execution of the current frame and going back to the previous
frame. One could even terminate classes in this way, i.e. skipping all the
methods defined after the ``end()``

... (some time passes) ...

BTW, I have just realized that we don't need a new ``end()`` function: it would be 
enough to extend the ``break`` statement. Currently, it works only inside 
loops, why not to extend it to terminate classes and modules? IMHO, it would be
very useful during debugging and refactoring. What do you people think? 
Or is there already same magic which can do what I ask for?
If not, take it as a feature request ;-)


Michele Simionato, Ph. D.
MicheleSimionato at libero.it
http://www.phyast.pitt.edu/~micheles/
---- Currently looking for a job ----