Re: [perl #75720] for(@a) optimisation causes problems

On Sun, Jun 13, 2010 at 06:23:30PM -0700, Father Chrysostomos wrote:
> $ perl -le' @a = (1,2,3); print shift @a for @a'
> 1
> 2
> 
> $ perl -le' @a = (1,2,3); print shift @a for (),@a'
> 1
> 2
> 3
> 
> There seems to be some optimisation for ‘for @array’ that has strange  
> side-effects.

The first one iterates over the elements of an array, the second over the
elements of a list. The array is being modified mid-iteration, while the
list isn't, which is why you see different results.

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