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Re: iterators: traversing arbitrary data structure

by ikegami (Pope)
on Jan 11, 2006 at 21:01 UTC ( #522565=note: print w/ replies, xml ) Need Help??


in reply to iterators: traversing arbitrary data structure

Update: OOPS! The solution in this post will show you all the values, but will not allow you to change them. See my reply to this post for a more appropriate solution.

Well, you could do

my $iter = get_value_iter($oWkBook); while ($iter->(my $item)) { print("$item\n"); }
if you defined get_value_iter as follows:
sub get_value_iter { my @values = @_; my $sub_iter; return sub { our $rv; local *rv = \$_[0]; for (;;) { if ($sub_iter) { if ($sub_iter->($rv)) { return 1; } undef $sub_iter; } return if not @values; $rv = shift(@values); while (ref($rv) eq 'SCALAR') { $rv = $$rv; } if (ref($rv) eq 'ARRAY') { $sub_iter = get_value_iter(@$rv); next; } if (ref($rv) eq 'HASH') { $sub_iter = get_value_iter(values %$rv); next; } return 1; } }; }

Scalar::Util's reftype can be used instead of ref if you wish to traverse objects.


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Re^2: iterators: traversing arbitrary data structure
by ikegami (Pope) on Jan 11, 2006 at 21:48 UTC

    You could do

    my $iter = get_value_iter($oWkBook); while ($iter->(my $item_ref)) { $$item_ref =~ s/^\s+\n$//; }
    if you defined get_value_iter as follows:
    sub get_value_iter { our $val; local *val = \$_[0]; if (ref($val) eq 'SCALAR') { my $ref = $val; return sub { my $sub_iter = get_value_iter($$ref); return $sub_iter->($_[0]); }; } if (ref($val) eq 'ARRAY') { my $ref = $val; my $key = 0; my $sub_iter; return sub { for (;;) { return 1 if $sub_iter && $sub_iter->($_[0]); return if $key >= @$ref; $sub_iter = get_value_iter($ref->[$key++]); } }; } if (ref($val) eq 'HASH') { my $ref = $val; my @keys = keys %$ref; my $sub_iter; return sub { for (;;) { return 1 if $sub_iter && $sub_iter->($_[0]); return if not @keys; $sub_iter = get_value_iter($ref->{shift @keys}); } }; } { my $ref = \$val; my $done = 0; return sub { return if $done; $_[0] = $ref; $done = 1; return 1; }; } }

    Scalar::Util's reftype can be used instead of ref if you wish to traverse objects.

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