In my code I often find structures of the form 

while ( 1 ) {

  # yadda yadda

  last if some_condition();

  # yadda yadda

}

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which suggests to me that a better, more general design for a loop would put the test between "pre" and "post" blocks: 
loop { # begin of enclosing block

  # pre-test code

} while ( some_condition() ) {

  # post-test code;

}

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Both pre- and post-blocks get executed repeatedly until the test in the middle fails, at which point control passes to immediately after the post-block. The pre-block (together with the loop keyword) would be optional; omitting it results in the standard while-loop. Likewise, the post-block is optional; omitting produces the standard do-while loop.

But Perl already gives a pretty close approximation for the attractive low price of an end-of-block redo: 

{

  # pre-code

  last if some_condition();

  # post-code

  redo;

}

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the lowliest monk

In reply to Re: Control Structures by tlm
in thread Control Structures by artist

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