Merge pull request #6 from titsuki/feature-clear

Add a clear method

Author: titsuki

README.md

@@ -132,6 +132,12 @@ Returns a minimum value item in the queue.
 
 Returns whether the queue is empty or not.
 
+### clear()
+
+    $heap.clear();
+
+Deletes all items in the queue.
+
 CAUTION
 =======
 

lib/Algorithm/MinMaxHeap.pm6

@@ -101,6 +101,14 @@ method pop-max() {
     }
 }
 
+method is-empty() returns Bool:D {
+    return @!nodes.elems == 0 ?? True !! False;
+}
+
+method clear() {
+    @!nodes = ();
+}
+
 method !compare($lhs, $rhs) returns Order:D {
     if ($!type ~~ Cool) {
 	return $lhs minmaxheap-cmp $rhs;
@@ -109,10 +117,6 @@ method !compare($lhs, $rhs) returns Order:D {
     }
 }
 
-method is-empty() returns Bool:D {
-    return @!nodes.elems == 0 ?? True !! False;
-}
-
 method !bubble-up($index) {
     if (self!is-minlevel($index)) {
 	if (self!has-parent($index) and (@!nodes[$index] minmaxheap-cmp @!nodes[self!find-parent($index)] == Order::More)) {
@@ -481,6 +485,12 @@ Returns a minimum value item in the queue.
 
 Returns whether the queue is empty or not.
 
+=head3 clear()
+
+       $heap.clear();
+
+Deletes all items in the queue.
+
 =head1 CAUTION
 
 Don't insert both numerical items and stringified items into the same queue.

t/07-clear.t

@@ -0,0 +1,22 @@
+use v6;
+use Test;
+use Algorithm::MinMaxHeap;
+
+{
+    my $heap = Algorithm::MinMaxHeap.new();
+    $heap.insert(0);
+    $heap.insert(1);
+    $heap.insert(2);
+    $heap.insert(3);
+    $heap.insert(4);
+    $heap.insert(5);
+    $heap.insert(6);
+    $heap.insert(7);
+    $heap.insert(8);
+
+    is $heap.nodes.elems, 9;
+    $heap.clear();
+    is $heap.nodes.elems, 0;
+}
+
+done-testing;