NestedMap 1.0

NestedMap is a module to make nesting map{}s inside map{}s easierc.

SYNOPSIS

# show all combinations of (A,B,C) (a,b,c) and (1,2,3)
print join("n",
nestedmap {
nestedmap {
nestedmap {
join(,@NestedMap::stack[0..2])
} qw(A B C)
} qw(a b c)
} qw(1 2 3)
);

# a zip() function for any number of lists of varying length
sub zipn {
my @args = @_;
[
nestedmap {
nestedmap {
defined($args[$_][$NestedMap::stack[1]]) ?
$args[$_][$NestedMap::stack[1]] :

} 0..$#args
} 0 .. max(map { $#{$_[$_]} } 0..$#args)
]
}

NB - older versions of perl may not like the code blocks I use in these examples.

You may have to use:

nestedmap sub { ... }, @list;

instead of

nestedmap { ... } @list;

See the test suite for examples of the above code modified to use that syntax.