1 files changed, 178 insertions, 0 deletions
diff --git a/lib/MDK/Common/DataStructure.pm b/lib/MDK/Common/DataStructure.pm
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+package MDK::Common::DataStructure;
+
+=head1 NAME
+
+MDK::Common::DataStructure - miscellaneous list/hash manipulation functions
+
+=head1 SYNOPSIS
+
+    use MDK::Common::DataStructure qw(:all);
+
+=head1 EXPORTS
+
+=over
+
+=item sort_numbers(LIST)
+
+numerical sort (small numbers at beginning)
+
+=item ikeys(HASH)
+
+aka I<sorted integer keys>, as simple as C<sort { $a E<lt>=E<gt> $b } keys>
+
+=item add2hash(HASH REF, HASH REF)
+
+adds to the first hash the second hash if the key/value is not already there
+
+=item add2hash_
+
+adds to the first hash the second hash if the key is not already there
+
+=item put_in_hash
+
+adds to the first hash the second hash, crushing existing key/values
+
+=item member(SCALAR, LIST)
+
+is the value in the list?
+
+=item invbool(SCALAR REF)
+
+toggles the boolean value
+
+=item listlength(LIST)
+
+returns the length of the list. Useful in list (opposed to array) context:
+
+    sub f { "a", "b" } 
+    my $l = listlength f();
+
+whereas C<scalar f()> would return "b"
+
+=item deref(REF)
+
+de-reference
+
+=item deref_array(REF)
+
+de-reference arrays:
+
+    deref_array [ "a", "b" ]	#=> ("a", "b")
+    deref_array "a" 		#=> "a" 
+
+=item is_empty_array_ref(SCALAR)
+
+is the scalar undefined or is the array empty
+
+=item is_empty_hash_ref(SCALAR)
+
+is the scalar undefined or is the hash empty
+
+=item uniq(LIST)
+
+returns the list with no duplicates (keeping the first elements)
+
+=item uniq_ { CODE } LIST
+
+returns the list with no duplicates according to the scalar results of CODE on each element of LIST (keeping the first elements)
+
+    uniq_ { $_->[1] } [ 1, "fo" ], [ 2, "fob" ], [ 3, "fo" ], [ 4, "bar" ]
+
+gives [ 1, "fo" ], [ 2, "fob" ], [ 4, "bar" ]
+
+=item difference2(ARRAY REF, ARRAY REF)
+
+returns the first list without the element of the second list
+
+=item intersection(ARRAY REF, ARRAY REF, ...)
+
+returns the elements which are in all lists
+
+=item next_val_in_array(SCALAR, ARRAY REF)
+
+finds the value that follow the scalar in the list (circular):
+C<next_val_in_array(3, [1, 2, 3])> gives C<1>
+(do not use a list with duplicates)
+
+=item group_by2(LIST)
+
+interprets the list as an ordered hash, returns a list of [key,value]:
+C<group_by2(1 => 2, 3 => 4, 5 => 6)> gives C<[1,2], [3,4], [5,6]>
+
+=item list2kv(LIST)
+
+interprets the list as an ordered hash, returns the keys and the values:
+C<list2kv(1 => 2, 3 => 4, 5 => 6)> gives C<[1,3,5], [2,4,6]>
+
+=back
+
+=head1 SEE ALSO
+
+L<MDK::Common>
+
+=cut
+
+
+use MDK::Common::Math;
+use MDK::Common::Func;
+
+
+use Exporter;
+our @ISA = qw(Exporter);
+our @EXPORT_OK = qw(sort_numbers ikeys add2hash add2hash_ put_in_hash member invbool listlength deref deref_array is_empty_array_ref is_empty_hash_ref uniq uniq_ difference2 intersection next_val_in_array group_by2 list2kv);
+our %EXPORT_TAGS = (all => [ @EXPORT_OK ]);
+
+
+sub sort_numbers { sort { $a <=> $b } @_ }
+sub ikeys { my %l = @_; sort { $a <=> $b } keys %l }
+sub put_in_hash { my ($a, $b) = @_; while (my ($k, $v) = each %{$b || {}}) { $a->{$k} = $v } $a }
+sub add2hash    { my ($a, $b) = @_; while (my ($k, $v) = each %{$b || {}}) { $a->{$k} ||= $v } $a }
+sub add2hash_   { my ($a, $b) = @_; while (my ($k, $v) = each %{$b || {}}) { exists $a->{$k} or $a->{$k} = $v } $a }
+sub member { my $e = shift; foreach (@_) { $e eq $_ and return 1 } 0 }
+sub invbool { my $a = shift; $$a = !$$a; $$a }
+sub listlength { scalar @_ }
+sub strcpy { substr($_[0], $_[2] || 0, length $_[1]) = $_[1] }
+sub deref { ref($_[0]) eq "ARRAY" ? @{$_[0]} : ref($_[0]) eq "HASH" ? %{$_[0]} : $_[0] }
+sub deref_array { ref($_[0]) eq "ARRAY" ? @{$_[0]} : $_[0] }
+
+sub is_empty_array_ref { my $a = shift; !defined $a || @$a == 0 }
+sub is_empty_hash_ref { my $a = shift; !defined $a || keys(%$a) == 0 }
+
+sub uniq { my %l; $l{$_} = 1 foreach @_; grep { delete $l{$_} } @_ }
+sub difference2 { my %l; @l{@{$_[1]}} = (); grep { !exists $l{$_} } @{$_[0]} }
+sub intersection { my (%l, @m); @l{@{shift @_}} = (); foreach (@_) { @m = grep { exists $l{$_} } @$_; %l = (); @l{@m} = () } keys %l }
+
+sub uniq_(&@) {
+    my $f = shift;
+    my %l;
+    $l{$f->($_)} = 1 foreach @_;
+    grep { delete $l{$f->($_)} } @_;
+}
+
+
+sub next_val_in_array {
+    my ($v, $l) = @_;
+    my %l = MDK::Common::Func::mapn(sub { @_ }, $l, [ @$l[1..$#$l], $l->[0] ]);
+    $l{$v};
+}
+
+
+sub list2kv { 
+    my (@k, @v);
+    for (my $i = 0; $i < @_; $i += 2) {	
+	push @k, $_[$i + 0];
+	push @v, $_[$i + 1];
+    }
+    \@k, \@v;
+}
+
+sub group_by2 {
+    my @l;
+    for (my $i = 0; $i < @_; $i += 2) {
+	push @l, [ $_[$i], $_[$i+1] ];
+    }
+    @l;
+}
+
+
+1;