NAME

Set::IntervalTree - Perform range-based lookups on sets of ranges.

SYNOPSIS

  use Set::IntervalTree;
  my $tree = Set::IntervalTree->new;
  $tree->insert("ID1",100,200);
  $tree->insert(2,50,100);
  $tree->insert({id=>3},520,700);
  $tree->insert($some_obj,1000,1100);

  my $results = $tree->fetch(400,800);
  my $window = $tree->window(100,200);
  print scalar(@$results)." intervals found.\n";

  # remove only items overlapping location 100..200 with values 
  # less than 100;
  my $removed = $tree->remove(100,200 sub {
    my ($item, $low, $high) = @_;
    return $item < 100;
  });

DESCRIPTION

Set::IntervalTree uses Interval Trees to store and efficiently look up ranges using a range-based lookup.

All intervals are half-open, i.e. [1,3), [2,6), etc.

EXPORTS

Nothing.

METHODS

my $tree = Set::IntervalTree->new;

  Creates a new interval tree object.

$tree->insert($object, $low, $high);

  Insert a range into the interval tree and associate it with a 
  perl scalar.

  $object can be any perl scalar. This is what will be returned by fetch().
  $low is the lower bound of the range.
  $high is the upper bound of the range.

  Ranges are represented as half-closed integer intervals.

my $results = $tree->fetch($low, $high)

  Return an arrayref of perl objects whose ranges overlap 
  the specified range.

  $low is the lower bound of the region to query.
  $high is the upper bound of the region to query.

my $results = $tree->fetch_window($low, $high)

  Return an arrayref of perl objects whose ranges are completely contained
  witin the specified range.

  $low is the lower bound of the region to query.
  $high is the upper bound of the region to query.

my $removed = $tree->remove($low, $high [, optional \&coderef]);

  Remove items in the tree that overlap the region from $low to $high. 
  A coderef can be passed in as an optional third argument for filtering
  what is removed. The coderef receives the stored item, the low point,
  and the high point as its arguments. If the result value of the coderef
  is true, the item is removed, otherwise the item remains in the tree.

  Returns the list of removed items.

my $removed = $tree->remove_window($low, $high [, optional \&coderef]);

  Remove items in the tree that are contained within the region from $low
  to $high.  A coderef can be passed in as an optional third argument
  for filtering what is removed. The coderef receives the stored item,
  the low point, and the high point as its arguments. If the result
  value of the coderef is true, the item is removed, otherwise the item
  remains in the tree.

  Returns the list of removed items.

LIMITATIONS

A $tree->print() serialization method might be useful for debugging.

SEE ALSO

The source code for this module contains a reusable template-based C++ header for Interval trees that might be useful.

AUTHOR

Ben Booth, <benbooth@cpan.org>

COPYRIGHT AND LICENSE

Copyright (C) 2012 by Ben Booth

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.10.1 or, at your option, any later version of Perl 5 you may have available.

cpanm Set::IntervalTree

perl -MCPAN -e shell
install Set::IntervalTree