Add code to display and step through access views.

src/CacheSim/Model.elm

@@ -15,3 +15,5 @@ type Msg
     | DeleteRawModel Int
     | UseHierarchy (Maybe CacheModelHierarchy)
     | Access Int
+    | AccessViewForward
+    | AccessViewBack

src/CacheSim/Update.elm

@@ -41,8 +41,31 @@ updateUseHierarchy cmh m =
 updateAccess : Int -> Model -> (Model, Cmd Msg)
 updateAccess i m =
     let
-        accessResult = Maybe.map (accessCacheHierarchy i) m.hierarchy
+        accessResult = Maybe.andThen (Result.toMaybe << accessCacheHierarchy i) m.hierarchy
-        newModel = m
+        newModel = { m | accessView = Maybe.map (\ar -> (ar, Down 0)) accessResult }
+        cmd = Cmd.none
+    in
+        (newModel, cmd)
+
+updateAccessViewForward : Model -> (Model, Cmd Msg)
+updateAccessViewForward m =
+    let
+        afterStep = Maybe.map accessViewForward m.accessView
+        replaceHierarchy avs h = List.map .output avs ++ List.drop (List.length avs) h
+        (newHierarchy, newAccessView) =
+            case afterStep of
+                Just (avs, Done) -> (Maybe.map (replaceHierarchy avs) m.hierarchy, Nothing)
+                as_ -> (m.hierarchy, as_)
+        newModel = { m | accessView = newAccessView, hierarchy = newHierarchy }
+        cmd = Cmd.none
+    in
+        (newModel, cmd)
+
+updateAccessViewBack : Model -> (Model, Cmd Msg)
+updateAccessViewBack m =
+    let
+        afterStep = Maybe.map accessViewBack m.accessView
+        newModel = { m | accessView = afterStep }
         cmd = Cmd.none
     in
         (newModel, cmd)

src/CacheSim/View.elm

@@ -2,6 +2,7 @@ module CacheSim.View exposing (..)
 import CacheSim.Raw exposing (..)
 import CacheSim.Model exposing (..)
 import CacheSim.Cache exposing (..)
+import CacheSim.AccessView exposing (..)
 import CacheSim.Hierarchy exposing (..)
 import Html exposing (Html, input, text, div, label, span, h2, h3, table, tr, td)
 import Html.Attributes exposing (type_, class, value, for, classList, disabled, colspan)
@@ -126,6 +127,21 @@ viewCacheHierarchy ch =
         , levels
         ]
         
+viewAccessView : Model -> AccessView -> Html Msg
+viewAccessView m av =
+    let
+        currentCache = Maybe.withDefault [] m.hierarchy
+    in
+        div [ class "access-view" ]
+            [ buttonWrapper
+                [ button "Forward" AccessViewForward
+                , button "Back" AccessViewBack
+                ]
+            , viewCacheHierarchy <| effectiveCacheHierarchy currentCache av
+            ]   
+
+viewAccessInput : Html Msg
+viewAccessInput = input [ type_ "button", onClick (Access 128), value "Access me" ] []
 
 viewError : Bool -> String -> Html Msg
 viewError hide e = span [ classList [ ("hidden", hide) ] ] [ text e ]
@@ -135,5 +151,6 @@ viewBase m =
     let
         rawView = viewRawCacheModelHierarchy m.rawHierarchy
         cacheView = Maybe.withDefault [] <| Maybe.map (List.singleton << viewCacheHierarchy) <| m.hierarchy
+        accessView = Maybe.withDefault [] <| Maybe.map (List.singleton << viewAccessView m) <| m.accessView
     in
-        div [] <| [ rawView ] ++ cacheView
+        div [] <| [ rawView, viewAccessInput] ++ cacheView ++ accessView

src/Main.elm

@@ -37,6 +37,8 @@ update msg m =
         DeleteRawModel i -> updateDeleteRawModel i m
         UseHierarchy cmh -> updateUseHierarchy cmh m
         Access i -> updateAccess i m
+        AccessViewForward -> updateAccessViewForward m
+        AccessViewBack -> updateAccessViewBack m
 
 subscriptions : Model -> Sub Msg
 subscriptions m = Sub.none