3 files changed, 80 insertions, 30 deletions

diff --git a/src/Tonkadur/Compute.elm b/src/Tonkadur/Compute.elm
index 489ab3b..2a3410f 100644
--- a/src/Tonkadur/Compute.elm
+++ b/src/Tonkadur/Compute.elm
@@ -160,7 +160,10 @@ newline : Tonkadur.Types.State -> Tonkadur.Types.Value
 newline state = (TextValue Newline)
 
 next_allocable_address : Tonkadur.Types.State -> Tonkadur.Types.Value
-next_allocable_address state = (IntValue state.next_allocable_address)
+next_allocable_address state =
+   if (List.isEmpty state.freed_addresses)
+   then (PointerValue [(".alloc." ++ (String.fromInt state.allocated_data))])
+   else (PointerValue [state.freed_addresses[0]])
 
 operation : (
       Tonkadur.Types.State ->
diff --git a/src/Tonkadur/Execute.elm b/src/Tonkadur/Execute.elm
index cf582dd..cf88968 100644
--- a/src/Tonkadur/Execute.elm
+++ b/src/Tonkadur/Execute.elm
@@ -89,23 +89,51 @@ initialize : (
       Tonkadur.Types.State
    )
 initialize type_name address state =
-   {state |
-      memory =
-         (Tonkadur.Types.apply_at_address
-            (Tonkadur.Types.value_to_list
-               (Tonkadur.Compute.compute state address)
-            )
-            (\last_addr dict ->
-               (Dict.insert
-                  last_addr
-                  (Tonkadur.Types.get_default state type_name)
-                  dict
+   let
+      new_state =
+         {state |
+            memory =
+               (Tonkadur.Types.apply_at_address
+                  (Tonkadur.Types.value_to_list
+                     (Tonkadur.Compute.compute state address)
+                  )
+                  (\last_addr dict ->
+                     (Dict.insert
+                        last_addr
+                        (Tonkadur.Types.get_default state type_name)
+                        dict
+                     )
+                  )
+                  state.memory
                )
-            )
-            state.memory
-         )
-      -- TODO: detect allocated memory for special handling.
-   }
+            -- TODO: detect allocated memory for special handling.
+         }
+   in
+      case address of
+         [single_element] ->
+            if (String.startsWith ".alloc." single_element)
+            then
+               if
+               (
+                  single_element
+                  == (".alloc." ++ (String.fromInt new_state.allocated_data))
+               )
+               then
+                  {new_state |
+                     allocated_data = new_state.allocated_data + 1
+                  }
+               else
+                  {new_state |
+                     freed_addresses =
+                        (List.filter
+                           (\addr -> (addr /= single_element))
+                           new_state.freed_addresses
+                        )
+                  }
+
+            else new_state
+
+         _ -> new_state
 
 prompt_command : (
       Tonkadur.Types.PromptInstructionData ->
@@ -161,17 +189,31 @@ remove : (
       Tonkadur.Types.State
    )
 remove address state =
-   {state |
-      memory =
-         (Tonkadur.Types.apply_at_address
-            (Tonkadur.Types.value_to_list
-               (Tonkadur.Compute.compute state address)
-            )
-            (\last_addr dict -> (Dict.remove last_addr dict))
-            state.memory
-         )
-      -- TODO: detect allocated memory for special handling.
-   }
+   let
+      new_state =
+         {state |
+            memory =
+               (Tonkadur.Types.apply_at_address
+                  (Tonkadur.Types.value_to_list
+                     (Tonkadur.Compute.compute state address)
+                  )
+                  (\last_addr dict -> (Dict.remove last_addr dict))
+                  state.memory
+               )
+         }
+   in
+      case address of
+         [single_element] ->
+            if (String.startsWith ".alloc." single_element)
+            then
+               {new_state |
+                  freed_addresses =
+                     (single_element :: new_state.freed_addresses)
+               }
+            else new_state
+
+         _ -> new_state
+
 
 resolve_choice : Tonkadur.Types.State -> Tonkadur.Types.State
 resolve_choice state =
diff --git a/src/Tonkadur/Types.elm b/src/Tonkadur/Types.elm
index 504695b..ec6c3c2 100644
--- a/src/Tonkadur/Types.elm
+++ b/src/Tonkadur/Types.elm
@@ -97,7 +97,8 @@ type alias State =
       available_options : (List Option),
       memorized_target : Value,
 
-      last_instruction_effect : InstructionEffect
+      last_instruction_effect : InstructionEffect,
+      freed_addresses : (List String)
    }
 
 --------------------------------------------------------------------------------
@@ -120,7 +121,8 @@ new_state =
       available_options = [],
       memorized_target = (PointerValue [""]),
 
-      last_instruction_effect = MustContinue
+      last_instruction_effect = MustContinue,
+      freed_addresses = []
    }
 
 value_to_bool : Value -> Bool
@@ -302,3 +304,6 @@ apply_at_address address fun memory =
             )
             memory
          )
+
+allow_continuing : State -> State
+allow_continuing state = {state | last_instruction_effect = MustContinue}