moved Array.delete to setting

It's not likely that 'undef' will work as intended for typed arrays but,
hey, all the old tests pass, plus two TODO'd ones.

src/classes/Array.pir

@@ -14,70 +14,19 @@ src/classes/Array.pir - Perl 6 Array class and related functions
     arrayproto.'!MUTABLE'()
 
     $P0 = get_hll_namespace ['Perl6Array']
-    '!EXPORT'('delete,exists,pop,push,shift,unshift', 'from'=>$P0, 'to_p6_multi'=>1)
+    '!EXPORT'('exists,pop,push,shift,unshift', 'from'=>$P0, 'to_p6_multi'=>1)
 .end
 
 
 =head2 Methods
 
-=item delete
-
-Remove items from an array.
-
-=cut
-
-.namespace ['Perl6Array']
-.sub 'delete' :method :multi() :subid('array_delete')
-    .param pmc indices :slurpy
-    .local pmc result
-    result = new ['List']
-    null $P99
-
-    indices.'!flatten'()
-  indices_loop:
-    unless indices goto indices_end
-    $I0 = shift indices
-    $P0 = self[$I0]
-    push result, $P0
-    self[$I0] = $P99
-
-  shorten:
-    $I0 = self.'elems'()
-    dec $I0
-  shorten_loop:
-    if $I0 < 0 goto shorten_end
-    $P0 = self[$I0]
-    if null $P0 goto do_shorten
-    $I1 = $P0.'defined'()
-    if $I1 goto shorten_end
-  do_shorten:
-    delete self[$I0]
-    dec $I0
-    goto shorten_loop
-  shorten_end:
-    goto indices_loop
-
-  indices_end:
-    .return (result)
-.end
-.sub '' :init :load
-    .local pmc block, signature
-    .const 'Sub' $P0 = "array_delete"
-    block = $P0
-    signature = new ["Signature"]
-    setprop block, "$!signature", signature
-    signature."!add_param"("@indices", 1 :named("slurpy"))
-    $P0 = get_hll_global 'Array'
-    signature."!add_implicit_self"($P0)
-.end
-
-
 =item exists(indices :slurpy)
 
 Return true if the elements at C<indices> have been assigned to.
 
 =cut
 
+.namespace ['Perl6Array']
 .sub 'exists' :method :multi() :subid('array_exists')
     .param pmc indices :slurpy
     .local int test

src/setting/Array.pm

@@ -1,6 +1,22 @@
 # "is export" on Array does not work (it's Perl6Array internally)
 
 class Array is also {
+    multi method delete(@array is rw: *@indices) {
+        my @result;
+        for @indices -> $index {
+            my $i = $index >= 0
+                        ?? $index
+                        !! * + $index;
+            @result.push(do { my $workaround = @array[$i] });
+            undefine @array[$i];
+            if $index == (@array - 1) | -1 {
+                @array.pop;
+            }
+        }
+        @array.pop while @array && !defined @array[* - 1];
+        return @result;
+    }
+
     multi method splice(@array is rw: $offset is copy = 0, $size? is copy, *@values) {
         my @spliced;
         my @deleted;
@@ -20,6 +36,10 @@ class Array is also {
     }
 }
 
+multi delete(@array is rw, *@indices) {
+    @array.delete(|@indices);
+}
+
 multi splice(@array is rw, $offset?, $size?, *@values) {
     @array.splice($offset,$size,@values);
 }