better error checking while optimizing expressions

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

@@ -186,7 +186,13 @@ public class TruthTable {
      * Adds a new variable
      */
     public void addVariable() {
-        addVariable("A");
+        char v = 'A';
+        Variable var;
+        do {
+            var = new Variable("" + v);
+            v++;
+        } while (variables.contains(var) && v <= 'Z');
+        addVariable(var);
     }
 
     /**
@@ -195,7 +201,16 @@ public class TruthTable {
      * @param name name of the variable
      */
     public void addVariable(String name) {
-        variables.add(new Variable(name));
+        addVariable(new Variable(name));
+    }
+
+    /**
+     * Adds a variable
+     *
+     * @param var the variable to add
+     */
+    public void addVariable(Variable var) {
+        variables.add(var);
         for (Result r : results)
             r.setValues(BoolTableByteArray.createDoubledValues(r.getValues()));
 

src/main/java/de/neemann/digital/builder/circuit/CircuitBuilder.java

@@ -28,8 +28,8 @@ import java.util.*;
 import static de.neemann.digital.draw.shapes.GenericShape.SIZE;
 
 /**
- * Builder to create a circuit from a set off expression
- * Is also able to create a state machine.
+ * Builder to create a circuit from a set of expressions.
+ * Is also able to create a finite state machine.
  *
  * @author hneemann
  */
@@ -43,6 +43,7 @@ public class CircuitBuilder implements BuilderInterface<CircuitBuilder> {
     private final ArrayList<Variable> sequentialVars;
     private final ArrayList<FragmentVisualElement> flipflops;
     private final boolean useJKff;
+    private final ArrayList<Variable> desiredVarOrdering;
     private int pos;
 
     /**
@@ -62,8 +63,20 @@ public class CircuitBuilder implements BuilderInterface<CircuitBuilder> {
      * @param useJKff      true if JK flip-flops should be used to create state machines instead of D flip-flops.
      */
     public CircuitBuilder(ShapeFactory shapeFactory, boolean useJKff) {
+        this(shapeFactory, useJKff, null);
+    }
+
+    /**
+     * Creates a new builder.
+     *
+     * @param shapeFactory ShapeFactory which is set to the created VisualElements
+     * @param useJKff      true if JK flip-flops should be used to create state machines instead of D flip-flops.
+     * @param varOrdering  the desired ordering of the variables, There may be more variables than required. Maybe null.
+     */
+    public CircuitBuilder(ShapeFactory shapeFactory, boolean useJKff, ArrayList<Variable> varOrdering) {
         this.shapeFactory = shapeFactory;
         this.useJKff = useJKff;
+        desiredVarOrdering = varOrdering;
         variableVisitor = new VariableVisitor();
         fragmentVariables = new ArrayList<>();
         fragments = new ArrayList<>();
@@ -285,6 +298,8 @@ public class CircuitBuilder implements BuilderInterface<CircuitBuilder> {
 
         // order bus variables
         Collection<Variable> variables = variableVisitor.getVariables();
+        if (desiredVarOrdering != null)
+            variables = order(variables, desiredVarOrdering);
         if (!sequentialVars.isEmpty())
             variables = order(variables, sequentialVars);
 

src/main/java/de/neemann/digital/gui/components/table/CheckResultListener.java

@@ -56,11 +56,11 @@ public class CheckResultListener implements ExpressionListener {
                 return;
             case one:
                 if (!calculate)
-                    throw new ExpressionException("internal minimization error: found false, expected true");
+                    throw new ExpressionException(Lang.get("err_minimizationFailed"));
                 break;
             case zero:
                 if (calculate)
-                    throw new ExpressionException("internal minimization error: found true, expected false");
+                    throw new ExpressionException(Lang.get("err_minimizationFailed"));
                 break;
         }
     }

src/main/java/de/neemann/digital/gui/components/table/TableDialog.java

@@ -507,7 +507,7 @@ public class TableDialog extends JDialog {
 
     private void createCircuit(boolean useJKff, ExpressionModifier... modifier) {
         try {
-            CircuitBuilder circuitBuilder = new CircuitBuilder(shapeFactory, useJKff);
+            CircuitBuilder circuitBuilder = new CircuitBuilder(shapeFactory, useJKff, model.getTable().getVars());
             new BuilderExpressionCreator(circuitBuilder, modifier).setUseJKOptimizer(useJKff).create(lastGeneratedExpressions);
             Circuit circuit = circuitBuilder.createCircuit();
             SwingUtilities.invokeLater(() -> new Main(null, library, circuit).setVisible(true));

src/main/resources/lang/lang_de.xml

@@ -462,6 +462,8 @@ Es sind nur {1} Variablen erlaubt, es wurden jedoch {2} gefunden.</string>
     <string name="err_varName_N_UsedTwice">Die Variable {0} wird mehrfach verwendet!</string>
     <string name="err_fileNeedsToBeSaved">Die Datei muss zunächst gespeichert werden!</string>
     <string name="err_recursiveNestingAt_N0">Die Schaltung {0} bindet sich selbst ein!</string>
+    <string name="err_minimizationFailed">Das Ergebnis der Minimierung ist nicht korrekt!
+Sind evtl. die Namen der Variablen nicht eindeutig?</string>
 
     <string name="key_AddrBits">Adress-Bits</string>
     <string name="key_AddrBits_tt">Anzahl der Adress-Bits die verwendet werden.</string>
@@ -744,7 +746,7 @@ Die Icons stammen aus dem Tango Desktop Project.</string>
     <string name="msg_fileNotAccessible">Dieser Dateiename ist nicht aus dem aktuellen Projekt importierbar!</string>
     <string name="msg_fileIsNotUnique">Der Dateiname ist nicht eindeutig!</string>
     <string name="msg_fileNotImportedYet">Die Datei wurde noch nicht importiert.</string>
-    <string name="msg_fileExists">Die Datei {0} existiert schon!</string>
+    <string name="msg_fileExists">Die Datei {0} existiert schon! Soll die Datei überschrieben werden?</string>
 
     <string name="ok">Ok</string>
     <string name="rot_0">0°</string>

src/main/resources/lang/lang_en.xml

@@ -449,6 +449,8 @@ allowed are {1} variables but {2} are found.</string>
     <string name="err_varName_N_UsedTwice">The variable {0} is used twice!</string>
     <string name="err_fileNeedsToBeSaved">The file needs to be saved!</string>
     <string name="err_recursiveNestingAt_N0">The circuit {0} imports itself!</string>
+    <string name="err_minimizationFailed">The result of the minimization is not correct!
+The names of the variables may not be unique.</string>
 
     <string name="key_AddrBits">Address Bits</string>
     <string name="key_AddrBits_tt">Number of address bits used.</string>
@@ -731,7 +733,7 @@ The icons are taken from the Tango Desktop Project.</string>
     <string name="msg_fileNotAccessible">The selected file name is not importable from the actual project!</string>
     <string name="msg_fileIsNotUnique">The file name is not unique!</string>
     <string name="msg_fileNotImportedYet">The file has not yet been imported.</string>
-    <string name="msg_fileExists">The file {0} already exists!</string>
+    <string name="msg_fileExists">The file {0} already exists! Do you want to overwrite the file?</string>
 
     <string name="ok">Ok</string>
     <string name="rot_0">0°</string>