[Python-Dev] PEP 340: Breaking out.

[Rodrigo Dias Arruda Senra]

[ Shane Hathaway ]:
> I'd like to suggest a small language enhancement that would fix this
> example.  Allow the break and continue statements to use a keyword,
> either "for" or "while", to state that the code should break out of both
> the block statement and the innermost "for" or "while" statement.  The
> example above would change to:
> 
>     for name in filenames:
>         opening(name) as f:
>             if f.read(2) == 0xFEB0:
>                 break for
> 
> This could be a separate PEP if necessary.  When a "break for" is used
> in a block statement, it should raise a new kind of exception,
> BreakForLoop, and the block statement should propagate the exception.
> When used outside a block statement, "break for" can use existing Python
> byte code to jump directly to the next appropriate statement.

 What about nested blocks ? When they act as iterators that would be
 desireable too.

 What to do then: 

  - baptize blocks  -> break <name>
  - keep them anonymous ->  break #enclosing_scope_counter
  - do not support them 

 cheers,
 Senra

-- 
Rodrigo Senra                 
--
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