Re: Arbitrarily Many Nested Loops

On 30 Mar 2006 01:32:11 -0800, Jacob JKW <jacobcdf@xxxxxxxxx> wrote:

David Formosa (aka ? the Platypus) wrote:

[...]

I quickly worked out one way to do this, no guarties as to effeceny.

sub closefor (&$@) {
my $sub = shift;
my $range = shift;

return sub {
for my $i (0..$range){
$sub->($i,@_)
}
}
}

sub mulitloop (&@) {
my $sub = shift;
for (@_) {
my $oldsub = $sub;
$sub = closefor {$oldsub->(@_)} $_;
}
$sub->();
}
[...]
mulitloop {
my $sum = 0;
my $product = 1;
for (my $i; $i<=@#_; $i++) {
$sum += $_[$i];
$product *= $f_raa->[$i]->[$_[$i]];
}
$prob_ra->[$sum] += $product;
} @$n_ra;

You know as clever and elegant as this method is, it actually runs
significantly than my original ugly cut-and-paste style,

Yeah after thinking about it the above code does some things
redundently and actually causes perl to do alot of extra needless
work. This should be a little more effecent.

sub calc_prob_ra ($$$;@) {
my $sum = shift;
my $prod = shift;
my $depth = shift;

if (@_) {
my $n = shift;

calc_prob_ra($sum+$n,$prod * $f_aa->[$depth]->[$_],$depth+1,@_)
for (0..$n);

} else {
$prob_ra->[$sum] += $prod;
}
}

calc_prob_ra(0,1,1,@$n_ra);

There should be signifigently less overhead in this case (I've
eleminated a needless loop, and all the closure creation and
derefrencing).

[...]

Anyway, I'm going to keep this code for further use and some later
date, but I eventyually went with John Krahn eval method posted
above.

I should bench test Mr Krahn's eval method vs my new method. But Its
to late and I'm far to tired.

--
Please excuse my spelling as I suffer from agraphia. See
http://dformosa.zeta.org.au/~dformosa/Spelling.html to find out more.
Free the Memes.
.

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