Nodes now has a state flag which is true if the node has a state.

Combinatorial elements don't have a state, flipflops do.

src/main/java/de/neemann/digital/analyse/ModelAnalyser.java

@@ -2,10 +2,7 @@ package de.neemann.digital.analyse;
 
 import de.neemann.digital.analyse.expression.BitSetter;
 import de.neemann.digital.analyse.quinemc.BoolTableIntArray;
-import de.neemann.digital.core.Model;
-import de.neemann.digital.core.NodeException;
-import de.neemann.digital.core.ObservableValue;
-import de.neemann.digital.core.Signal;
+import de.neemann.digital.core.*;
 import de.neemann.digital.core.flipflops.FlipflopD;
 import de.neemann.digital.lang.Lang;
 
@@ -36,6 +33,10 @@ public class ModelAnalyser {
         inputs = checkBinary(model.getInputs());
         outputs = checkBinary(model.getOutputs());
 
+        for (Node n : model)
+            if (n.hasState() && !(n instanceof FlipflopD))
+                throw new AnalyseException(Lang.get("err_cannotAnalyse_N", n.getClass().getSimpleName()));
+
         int i = 0;
         List<FlipflopD> flipflops = model.findNode(FlipflopD.class);
         for (FlipflopD ff : flipflops) {

src/main/java/de/neemann/digital/core/Model.java

@@ -1,15 +1,11 @@
 package de.neemann.digital.core;
 
-import de.neemann.digital.core.memory.ROM;
 import de.neemann.digital.core.wiring.Break;
 import de.neemann.digital.core.wiring.Clock;
 import de.neemann.digital.core.wiring.Reset;
 import de.neemann.digital.lang.Lang;
 
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
+import java.util.*;
 
 /**
  * The Model contains all the nodes of the model.
@@ -38,7 +34,7 @@ import java.util.List;
  * @author hneemann
  * @see de.neemann.digital.core.element.Element#registerNodes(Model)
  */
-public class Model {
+public class Model implements Iterable<Node> {
     /**
      * Maximal number of calculation loops before oscillating behaviour is detected
      */
@@ -47,10 +43,10 @@ public class Model {
     private final ArrayList<Clock> clocks;
     private final ArrayList<Break> breaks;
     private final ArrayList<Reset> resets;
+
     private final ArrayList<Signal> signals;
     private final ArrayList<Signal> inputs;
     private final ArrayList<Signal> outputs;
-    private final ArrayList<ROM> roms;
 
     private final ArrayList<Node> nodes;
     private final ArrayList<ModelStateObserver> observers;
@@ -69,7 +65,6 @@ public class Model {
         this.signals = new ArrayList<>();
         this.outputs = new ArrayList<>();
         this.inputs = new ArrayList<>();
-        this.roms = new ArrayList<>();
         this.nodes = new ArrayList<>();
         this.nodesToUpdateAct = new ArrayList<>();
         this.nodesToUpdateNext = new ArrayList<>();
@@ -433,23 +428,6 @@ public class Model {
         return n;
     }
 
-
-    /**
-     * registers a ROM to the model
-     *
-     * @param rom the ROM
-     */
-    public void addRomListing(ROM rom) {
-        roms.add(rom);
-    }
-
-    /**
-     * @return all registered Roms
-     */
-    public ArrayList<ROM> getRoms() {
-        return roms;
-    }
-
     /**
      * fires a model changed event to all listeners
      */
@@ -478,4 +456,9 @@ public class Model {
                 found.add((NODE) n);
         return found;
     }
+
+    @Override
+    public Iterator<Node> iterator() {
+        return nodes.iterator();
+    }
 }

src/main/java/de/neemann/digital/core/Node.java

@@ -9,9 +9,26 @@ package de.neemann.digital.core;
  */
 public abstract class Node implements Observer {
 
+    private final boolean hasState;
     private Model model;
     private int version;
 
+    /**
+     * Creates new stateless Node
+     */
+    public Node() {
+        this(false);
+    }
+
+    /**
+     * Creates a new node
+     *
+     * @param hasState true if node has a state
+     */
+    public Node(boolean hasState) {
+        this.hasState = hasState;
+    }
+
     /**
      * Sets the model for this node.
      *
@@ -58,4 +75,11 @@ public abstract class Node implements Observer {
         model.add(this);
     }
 
+    /**
+     * @return true if the element has a state and is not only combinatorial
+     */
+    public boolean hasState() {
+        return hasState;
+    }
+
 }

src/main/java/de/neemann/digital/core/flipflops/FlipflopD.java

@@ -44,6 +44,7 @@ public class FlipflopD extends Node implements Element {
      * @param attributes the attributes
      */
     public FlipflopD(ElementAttributes attributes) {
+        super(true);
         bits = attributes.getBits();
         this.q = new ObservableValue("Q", bits);
         this.qn = new ObservableValue("\u00ACQ", bits);

src/main/java/de/neemann/digital/core/flipflops/FlipflopJK.java

@@ -43,6 +43,7 @@ public class FlipflopJK extends Node implements Element {
      * @param attributes the attributes
      */
     public FlipflopJK(ElementAttributes attributes) {
+        super(true);
         this.q = new ObservableValue("Q", 1);
         this.qn = new ObservableValue("\u00ACQ", 1);
         isProbe = attributes.get(Keys.VALUE_IS_PROBE);

src/main/java/de/neemann/digital/core/flipflops/FlipflopRS.java

@@ -43,6 +43,7 @@ public class FlipflopRS extends Node implements Element {
      * @param attributes the attributes
      */
     public FlipflopRS(ElementAttributes attributes) {
+        super(true);
         this.q = new ObservableValue("Q", 1);
         this.qn = new ObservableValue("\u00ACQ", 1);
         isProbe = attributes.get(Keys.VALUE_IS_PROBE);

src/main/java/de/neemann/digital/core/flipflops/FlipflopT.java

@@ -41,6 +41,7 @@ public class FlipflopT extends Node implements Element {
      * @param attributes the attributes
      */
     public FlipflopT(ElementAttributes attributes) {
+        super(true);
         this.q = new ObservableValue("Q", 1);
         this.qn = new ObservableValue("\u00ACQ", 1);
         isProbe = attributes.get(Keys.VALUE_IS_PROBE);

src/main/java/de/neemann/digital/core/memory/Counter.java

@@ -39,6 +39,7 @@ public class Counter extends Node implements Element {
      * @param attributes the elements attributes
      */
     public Counter(ElementAttributes attributes) {
+        super(true);
         int bits = attributes.getBits();
         this.out = new ObservableValue("out", bits);
         this.ovf = new ObservableValue("ovf", 1);

src/main/java/de/neemann/digital/core/memory/RAMDualPort.java

@@ -53,6 +53,7 @@ public class RAMDualPort extends Node implements Element, RAMInterface {
      * @param attr the elemets attributes
      */
     public RAMDualPort(ElementAttributes attr) {
+        super(true);
         bits = attr.get(Keys.BITS);
         output = createOutput();
         addrBits = attr.get(Keys.ADDR_BITS);

src/main/java/de/neemann/digital/core/memory/ROM.java

@@ -106,11 +106,11 @@ public class ROM extends Node implements Element {
         return listFile;
     }
 
-    @Override
-    public void setModel(Model model) {
-        super.setModel(model);
-        if (showList && listFile != null)
-            model.addRomListing(this);
+    /**
+     * @return true if there is a listing to show
+     */
+    public boolean showListing() {
+        return showList && listFile != null;
     }
 
     /**

src/main/java/de/neemann/digital/core/memory/Register.java

@@ -42,6 +42,7 @@ public class Register extends Node implements Element {
      * @param attributes the elements attributes
      */
     public Register(ElementAttributes attributes) {
+        super(true);
         bits = attributes.getBits();
         this.q = new ObservableValue("Q", bits);
         isProbe = attributes.get(Keys.VALUE_IS_PROBE);

src/main/java/de/neemann/digital/gui/Main.java

@@ -625,7 +625,8 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
 
             if (settings.get(Keys.SHOW_LISTING)) {
                 int i = 0;
-                for (ROM rom : model.getRoms())
+                for (ROM rom : model.findNode(ROM.class))
+                    if (rom.showListing())
                         try {
                             windowPosManager.register("rom" + (i++), new ROMListingDialog(this, rom)).setVisible(true);
                         } catch (IOException e) {

src/main/resources/lang/lang_de.properties

@@ -196,6 +196,7 @@ err_pinMap_noEqualsfound=Kein \"=\" gefunden!
 err_pinMap_NoNameForPin_N=Kein Name f\u00FCr Pin {0}
 err_pinMap_input_N_notAllowed=Eingang {0} ist nicht erlaubt!
 err_pinMap_output_N_notAllowed=Ausgang {0} ist nicht erlaubt!
+err_cannotAnalyse_N=Element {0} kann nicht analysiert werden.
 
 attr_dialogTitle=Eigenschaften
 msg_errorEditingValue=Fehler bei der Eingabe eines Wertes

src/main/resources/lang/lang_en.properties

@@ -176,6 +176,7 @@ err_pinMap_noEqualsfound=No = found!
 err_pinMap_NoNameForPin_N=No Name for pin {0}
 err_pinMap_input_N_notAllowed=Input {0} not allowed!
 err_pinMap_output_N_notAllowed=Output {0} not allowed!
+err_cannotAnalyse_N=Cannot analyse Node {0}
 
 attr_dialogTitle=Attributes