speed-up-objectkeeper.diff

diff --git a/lib/Inline/Language/ObjectKeeper.pm6 b/lib/Inline/Language/ObjectKeeper.pm6
index 27fc538..5ea758c 100644
--- a/lib/Inline/Language/ObjectKeeper.pm6
+++ b/lib/Inline/Language/ObjectKeeper.pm6
@@ -1,27 +1,38 @@
 class Inline::Language::ObjectKeeper {
-    has @!objects;
-    has $!last_free = -1;
+    has IterationBuffer $!objects;
+    has $!last_free;
 
-    method keep(Any:D $value) returns Int {
-        my $index = $!last_free;
-        if $index != -1 {
-            $!last_free = @!objects.AT-POS($index);
-            @!objects.ASSIGN-POS($index, $value);
-            $index
+    submethod BUILD() {
+        $!objects := IterationBuffer.new;
+        $!last_free := -1;
+    }
+
+    method push($value is raw) {
+        my $objects := $!objects;
+        $objects.push($value);
+        $objects.elems - 1
+    }
+
+    method keep(Any:D $value is raw) returns Int {
+        my $index := $!last_free;
+        if $index == -1 {
+            self.push($value)
         }
         else {
-            @!objects.push($value);
-            @!objects.end
+            my $objects := $!objects;
+            $!last_free := $objects.AT-POS($index);
+            $objects.BIND-POS($index, $value);
+            $index
         }
     }
 
     method get(Int $index) returns Any:D {
-        @!objects[$index];
+        $!objects.AT-POS($index);
     }
 
     method free(Int $index --> Nil) {
-        @!objects.ASSIGN-POS($index, $!last_free);
-        $!last_free = $index;
+        $!objects.BIND-POS($index, $!last_free);
+        $!last_free := $index;
     }
 }