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## --------------------------------------------------------------------------- |
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## $Id: Ref.pm,v 1.3 2003/02/20 19:33:28 joko Exp $ |
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## --------------------------------------------------------------------------- |
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## $Log: Ref.pm,v $ |
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## Revision 1.3 2003/02/20 19:33:28 joko |
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## refactored code from Data::Transform::Deep |
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## + sub ref_slot |
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## + sub expr2perl |
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## |
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## Revision 1.2 2003/02/20 18:55:46 joko |
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## + minor cosmetic update |
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## |
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## Revision 1.1 2003/01/22 17:59:22 root |
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## + refactored from Mail::Audit::Dispatch |
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## |
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## --------------------------------------------------------------------------- |
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|
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|
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package Data::Mungle::Code::Ref; |
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|
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use strict; |
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use warnings; |
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|
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require Exporter; |
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our @ISA = qw( Exporter ); |
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our @EXPORT_OK = qw( |
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&get_coderef |
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&ref_slot |
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); |
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|
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|
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sub get_coderef { |
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my $codepack = shift; |
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my $method = shift; |
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$codepack || return '[error]'; |
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$method ||= ''; |
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$method && ($codepack .= '::'); |
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return eval '\&' . $codepack . $method . ';'; |
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} |
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|
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|
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# this function seems to do similar stuff like these below (refexpr2perlref & co.) |
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# TODO: maybe this mechanism can be replaced completely through some nice module from CPAN .... ? ;-) |
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sub _ref_slot_bylist { |
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my $var = shift; |
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my $indexstack_ref = shift; |
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my @indexstack = @{$indexstack_ref}; |
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my $joiner = '->'; |
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my @evlist; |
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foreach (@indexstack) { |
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my $elem; |
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if ($_ =~ m/\d+/) { $elem = "[$_]"; } |
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if ($_ =~ m/\D+/) { $elem = "{$_}"; } |
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push @evlist, $elem; |
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} |
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my $evstring = join($joiner, @evlist); |
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$evstring = 'return $var->' . $evstring . ';'; |
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#print "ev: $evstring\n"; |
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return eval($evstring); |
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} |
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|
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|
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sub ref_slot { |
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|
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my $obj = shift; |
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my $expr = shift; |
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my $values = shift; |
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my $delimiter = shift; |
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|
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$delimiter ||= '->'; |
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|
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my $value; |
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# detect for callback (code-reference) |
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if (ref($expr) eq 'CODE') { |
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$value = &$expr($obj); |
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|
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} elsif (ref($expr) eq 'ARRAY') { |
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return _ref_slot_bylist($obj, $expr); |
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|
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} elsif ($expr =~ m/$delimiter/) { |
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# use expr as complex object reference declaration (obj->subObj->subSubObj->0->attribute) |
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(my $objPerlRefString, my $parts) = expr2perl($expr, $delimiter); |
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|
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# trace |
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#print "expr: $expr", "\n"; |
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#print "objPerlRefString: $objPerlRefString", "\n"; |
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|
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my $evstr = '$obj' . '->' . $objPerlRefString; |
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|
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# trace |
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#print "eval: $evstr", "\n"; |
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|
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$value = eval($evstr); |
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die ($@) if $@; |
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|
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# if value isn't set, try to set it |
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my $callbackMap; |
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if ($values) { |
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#if (ref $values eq 'HASH') { |
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if (ref $values eq 'Data::Map') { |
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$callbackMap = $values->getAttributes(); |
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} else { |
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# apply $values as single value to referenced slot |
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#print "APPLY!", "\n"; |
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eval('$obj' . '->' . $objPerlRefString . ' = $values;'); |
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die ($@) if $@; |
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} |
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} |
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|
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# determine $values - if it's a hashref, use it as a "valueMap" |
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# "fallback" to callbackMap |
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# callbacks are applied this way: |
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# take the last element of the expression parts and check if this string exists as a key in the callback-map |
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if (!$value && $callbackMap) { |
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#print Dumper($callbackMap); |
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|
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# prepare needle |
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my @parts = @$parts; |
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my $count = $#parts; |
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my $needle = $parts[$count]; |
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|
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# prepare haystack |
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my @haystack = keys %$callbackMap; |
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if (grep($needle, @haystack)) { |
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$value = $callbackMap->{$needle}->(); |
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#print "value: ", $value, "\n"; |
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} |
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} |
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|
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} else { |
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# use expr as simple scalar key (attributename) |
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$value = $obj->{$expr}; |
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} |
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|
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return $value; |
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|
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} |
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|
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|
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sub expr2perl { |
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my $expr = shift; |
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my $delimiter = shift; |
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|
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$delimiter = quotemeta($delimiter); |
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|
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# split expression by dereference operators first |
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my @parts_pure = split(/$delimiter/, $expr); |
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|
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# wrap []'s around each part, if it consists of numeric characters only (=> numeric = array-index), |
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# use {}'s, if there are word-characters in it (=> alphanumeric = hash-key) |
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my @parts_capsule = @parts_pure; |
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map { |
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m/^\d+$/ && ($_ = "[$_]") || ($_ = "{$_}"); |
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} @parts_capsule; |
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|
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# join parts with dereference operators together again and return built string |
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return (join('->', @parts_capsule), \@parts_pure); |
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} |
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|
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|
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1; |
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__END__ |
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