Concrete Proposal: while ... and while ...

[Phil Hunt]

In article <374AD624.AB93C9CB at infercor.no>
           paulb at infercor.no "Paul Boddie" writes:
> Whilst I don't lie awake at nights worrying about all the "while 1"s out there
> up to no good, it would be nice to provide a better way of expressing loops with> the continuation/termination condition not being at the start. Since "do" is
> considered off-limits, we could consider other keywords:
> 
> while:          # No getting away from this, sadly.
>   first_part
> break if test2  # Imaginative use of existing keywords.
>                 # No second block, however. It could confuse.

There is already a syntax for `if' and `break' that does this, ie:
   if test2: break

So what you are suggesting could be generalized, so that all 
statements for the form:

   if test: do_something

can be rewritten as:

   do_something if test

This is useful, because it offers the programmer different ways to do
things -- different programmers prefer different ways of doing things,
so this way they'll all get what they want.

In fact, there already exists a language designed on these principles.
It is called Perl. (Some people have even gone as far to suggest that
Perl should replace Python as a general-purpose scripting language 
because of its superior and easier-to-understand syntax). So I suggest
that Python 2.0 should include the entire syntax of Perl, as well as
the ``and while test:'' and ``break if test'' constructs.

-- 
Phil Hunt....philh at vision25.demon.co.uk