Re: Readline using foreach and while

On 2008-03-27 04:45, szr <szrRE@xxxxxxxxxxxxxxx> wrote:
nolo contendere wrote:
Provably untrue. See Ben's example. I'll restate the concept below.

my @ary = qw/a b c/;
# for (@ary, ()) {
# for ( (), @ary ) {
for ( @ary ) {
push @ary, 'd' if /c/;
print;
}

...

only the uncommented 'for' line prints a 'd' at the end. so what you
say MAY be true if LIST is ONLY an array.

Isn't that because the two commented one are two lists being combined
into a new list, and it's *that* new list that's being iterated over, so
even if you add to @ary, it doesn't change the "new list", which is just
that, a new list created at the start of the loop before iterating
begins - therefore the values of the new list are set and @ary has
nothing to do with it after the create of the "new list."

Yes. But the same should be true for

for (@ary) {
...
}

for() expects a list, the list is constructed from the elements of @ary.
If you modify @ary after the list is constructed, the list shouldn't be
affected, but it is. I think Ben Morrow is right here: This smells like
an optimization: If there is only a single array, it can be used
directly instead of creating a list from it.

hp
.

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