Implement the main loop

bjforth/src/main/java/bjforth/machine/Machine.java

@@ -102,20 +102,49 @@ public void jumpTo(Integer address) {
     state.setInstructionPointer(address);
   }
 
-  /**
-   * Executes exactly ONE memory cell and stops.
-   *
-   * <p>To be used for debugging/testing purposes.
-   */
+  public void DOCOL(Boolean calledByPrimitive) {
+    pushToReturnStack(getNextInstructionPointer());
+    if (!calledByPrimitive) {
+      setNextInstructionPointer(getInstrcutionPointer() + 1);
+    }
+  }
+
+  private Integer threadedCodeDepth = 0;
+
+  public void enterThreadedCode() {
+    threadedCodeDepth += 1;
+  }
+
+  public void exitThreadedCode() {
+    if (threadedCodeDepth == 0) {
+      throw new MachineException("Invalid threadedCode depth.");
+    } else {
+      threadedCodeDepth -= 1;
+    }
+  }
+
+  private void applyThreadedCode(Integer IP) {
+    if (threadedCodeDepth > 0) {
+      setNextInstructionPointer(IP + 1);
+    }
+  }
+
+  /** Executes exactly ONE memory cell and stops. */
   public void step() {
     var IP = state.getInstructionPointer();
     var content = getMemoryAt(IP);
     if (content instanceof NativeSubroutine nativeSubroutine) {
       nativeSubroutine.call(this);
     } else if (content instanceof Integer address) {
-      state.setInstructionPointer(address);
+      jumpTo(address);
+      applyThreadedCode(IP);
+    } else if (content instanceof String s && "DOCOL".equals(s)) {
+      enterThreadedCode();
+      DOCOL(false);
+      jumpTo(getInstrcutionPointer() + 1);
     } else {
-      throw new MachineException("don't know how to execute *(%d)".formatted(IP));
+      //      throw new MachineException("don't know how to execute *(%d)".formatted(IP));
+      jumpTo(getInstrcutionPointer() + 1);
     }
   }
 
@@ -136,4 +165,16 @@ public void loop() {
       step();
     }
   }
+
+  public static void main(String[] args) {
+    System.out.println("bjForth <https://github.com/bahmanm/bjforth>");
+    System.out.println("⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯");
+
+    var state = new MachineState(0, 0, new Memory(), new Dictionary(), new Stack(), new Stack());
+    var machine = new Machine(state); // Bootstraps the components like memory and dictionary
+    var QUITaddr = machine.getDictionaryItem("QUIT").get().getAddress();
+    machine.setNextInstructionPointer(machine.getDictionaryItem("INTERPRET").get().getAddress());
+    machine.jumpTo(QUITaddr);
+    machine.loop();
+  }
 }

bjforth/src/main/java/bjforth/machine/Stack.java

@@ -35,11 +35,11 @@ class Stack {
   }
 
   public Object pop() {
-    return data.removeLast();
+    return data.removeFirst();
   }
 
   public void push(Object item) {
-    data.addLast(item);
+    data.addFirst(item);
   }
 
   public Object peek() {

bjforth/src/main/java/bjforth/primitives/COLON.java

@@ -26,12 +26,12 @@
 public class COLON implements Primitive {
   @Override
   public void execute(Machine machine) {
+    machine.DOCOL(true);
     WORD().execute(machine);
     CREATE().execute(machine);
 
     var LATESTvalue = (Integer) machine.getMemoryAt(Variables.get("LATEST").getAddress());
-    var DOCOLaddr = machine.getDictionaryItem("DOCOL").get().getAddress();
-    machine.setMemoryAt(LATESTvalue, DOCOLaddr);
+    machine.setMemoryAt(LATESTvalue, "DOCOL");
     machine.setMemoryAt(Variables.get("HERE").getAddress(), LATESTvalue + 1);
     machine.pushToParameterStack(LATESTvalue);
     HIDDEN().execute(machine);

bjforth/src/main/java/bjforth/primitives/EXIT.java

@@ -28,6 +28,7 @@ public void execute(Machine machine) {
     try {
       var value = (Integer) machine.popFromReturnStack();
       machine.setNextInstructionPointer(value);
+      machine.exitThreadedCode();
     } catch (NoSuchElementException _ex) {
       throw new MachineException("Return stack empty.");
     }

bjforth/src/main/java/bjforth/primitives/INTERPRET.java

@@ -18,6 +18,9 @@
  */
 package bjforth.primitives;
 
+import static bjforth.primitives.PrimitiveFactory.FIND;
+import static bjforth.primitives.PrimitiveFactory.WORD;
+
 import bjforth.machine.Machine;
 import bjforth.machine.MachineException;
 import bjforth.variables.Variables;
@@ -29,13 +32,13 @@ public void execute(Machine machine) {
     var HEREaddr = Variables.get("HERE").getAddress();
     var HEREvalue = (Integer) machine.getMemoryAt(HEREaddr);
 
-    PrimitiveFactory.WORD().execute(machine);
+    WORD().execute(machine);
     var obj = machine.peekIntoParameterStack();
     try {
-      PrimitiveFactory.FIND().execute(machine);
+      FIND().execute(machine);
       var dictItem = machine.getDictionaryItem((Integer) machine.popFromParameterStack()).get();
       if (STATE == 0 || dictItem.getIsImmediate()) {
-        machine.setNextInstructionPointer(dictItem.getAddress());
+        machine.jumpTo(dictItem.getAddress());
       } else {
         machine.setMemoryAt(HEREvalue, dictItem.getAddress());
         machine.setMemoryAt(HEREaddr, (Integer) machine.getMemoryAt(HEREaddr) + 1);
@@ -62,4 +65,9 @@ public void execute(Machine machine) {
       }
     }
   }
+
+  @Override
+  public Boolean isBypassNextInstructionPointer() {
+    return true;
+  }
 }

bjforth/src/main/java/bjforth/primitives/Primitive.java

@@ -27,9 +27,8 @@ public interface Primitive extends NativeSubroutine {
   default void call(Machine machine) {
     execute(machine);
     if (!isBypassNextInstructionPointer()) {
-      var nextWordAddr = machine.getNextInstructionPointer();
-      machine.setNextInstructionPointer(nextWordAddr + 1);
-      machine.jumpTo(nextWordAddr);
+      var NIP = machine.getNextInstructionPointer();
+      machine.jumpTo(NIP);
     }
   }
 

bjforth/src/main/java/bjforth/primitives/PrimitiveFactory.java

@@ -107,12 +107,6 @@ static Primitive DIV() {
     return containerDIV.get();
   }
 
-  private static PrimitiveContainer containerDOCOL = new PrimitiveContainer(DOCOL::new);
-
-  static Primitive DOCOL() {
-    return containerDOCOL.get();
-  }
-
   private static PrimitiveContainer containerDROP = new PrimitiveContainer(DROP::new);
 
   static Primitive DROP() {
@@ -395,6 +389,12 @@ static Primitive TOR() {
     return containerTOR.get();
   }
 
+  private static PrimitiveContainer containerTOSTRING = new PrimitiveContainer(TOSTRING::new);
+
+  static Primitive TOSTRING() {
+    return containerTOSTRING.get();
+  }
+
   private static PrimitiveContainer containerTWODROP = new PrimitiveContainer(TWODROP::new);
 
   static Primitive TWODROP() {
@@ -477,7 +477,6 @@ static Primitive ZNEQU() {
           containerDECR4,
           containerDFA,
           containerDIV,
-          containerDOCOL,
           containerDROP,
           containerDSPFETCH,
           containerDSPSTORE,
@@ -525,6 +524,7 @@ static Primitive ZNEQU() {
           containerSWAP,
           containerTELL,
           containerTOR,
+          containerTOSTRING,
           containerTWODROP,
           containerTWODUP,
           containerTWOSWAP,

bjforth/src/main/java/bjforth/primitives/QUIT.java

@@ -25,15 +25,14 @@ public class QUIT implements Primitive {
 
   @Override
   public void execute(Machine machine) {
+    machine.DOCOL(true);
     try {
       while (true) {
         machine.popFromReturnStack();
       }
     } catch (NoSuchElementException _ex) { // Return stack is empty
     }
-    var nip = machine.getNextInstructionPointer();
-    PrimitiveFactory.INTERPRET().execute(machine);
-    machine.setNextInstructionPointer(nip);
+    machine.setNextInstructionPointer(machine.getDictionaryItem("QUIT").get().getAddress());
     machine.jumpTo(machine.getDictionaryItem("INTERPRET").get().getAddress());
   }
 

bjforth/src/main/java/bjforth/primitives/SEMICOLON.java

@@ -26,8 +26,11 @@
 public class SEMICOLON implements Primitive {
   @Override
   public void execute(Machine machine) {
+    machine.DOCOL(true);
+    machine.enterThreadedCode(); // TODO TO be removed.
     var HEREvalue = (Integer) machine.getMemoryAt(Variables.get("HERE").getAddress());
     machine.setMemoryAt(HEREvalue, machine.getDictionaryItem("EXIT").get().getAddress());
+    machine.setMemoryAt(Variables.get("HERE").getAddress(), HEREvalue + 1);
     var LATESTvalue = (Integer) machine.getMemoryAt(Variables.get("LATEST").getAddress());
     machine.pushToParameterStack(LATESTvalue);
     HIDDEN().execute(machine);
@@ -44,9 +47,4 @@ public Boolean isImmediate() {
   public String getName() {
     return ";";
   }
-
-  @Override
-  public Boolean isBypassNextInstructionPointer() {
-    return true;
-  }
 }

bjforth/src/main/java/bjforth/primitives/DOCOL.java → bjforth/src/main/java/bjforth/primitives/TOSTRING.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2022 Bahman Movaqar
+ * Copyright 2024 Bahman Movaqar
  *
  * This file is part of bjForth.
  *
@@ -20,11 +20,10 @@
 
 import bjforth.machine.Machine;
 
-class DOCOL implements Primitive {
-
+public class TOSTRING implements Primitive {
   @Override
   public void execute(Machine machine) {
-    machine.pushToReturnStack(machine.getNextInstructionPointer());
-    machine.setNextInstructionPointer(machine.getInstrcutionPointer() + 1);
+    var obj = machine.peekIntoParameterStack();
+    System.out.println(obj.toString());
   }
 }

bjforth/src/test/java/bjforth/primitives/ADDSTORETest.java

@@ -19,12 +19,10 @@
 package bjforth.primitives;
 
 import static bjforth.machine.BootstrapUtils.getPrimitiveAddress;
-import static bjforth.machine.InstructionPointerBuilder.anInstructionPointer;
 import static bjforth.machine.MachineAssertions.*;
 import static bjforth.machine.MachineBuilder.aMachine;
 import static bjforth.machine.MachineStateBuilder.aMachineState;
 import static bjforth.machine.MemoryBuilder.aMemory;
-import static bjforth.machine.NextInstructionPointerBuilder.aNextInstructionPointer;
 import static bjforth.machine.ParameterStackBuilder.aParameterStack;
 import static org.assertj.core.api.Assertions.*;
 
@@ -59,17 +57,12 @@ void worksOk() {
 
     // THEN
     assertThat(actualState)
-        .hasInstructionPointerEqualTo(anInstructionPointer().with(referenceState).plus(1).build())
-        .hasNextInstructionPointerEqualTo(
-            aNextInstructionPointer().with(referenceState).plus(1).build())
-        .hasDictionaryEqualTo(referenceState)
         .hasMemoryEqualTo(
             aMemory()
                 .with(referenceState)
                 .with(parameterAddress, parameterValue + increment)
                 .build())
-        .hasParameterStackEqualTo(aParameterStack().build())
-        .hasReturnStackEqualTo(referenceState);
+        .hasParameterStackEqualTo(aParameterStack().build());
   }
 
   @DisplayName("should throw if parameter stack top is not a number.")

bjforth/src/test/java/bjforth/primitives/ADDTest.java

@@ -19,12 +19,10 @@
 package bjforth.primitives;
 
 import static bjforth.machine.BootstrapUtils.getPrimitiveAddress;
-import static bjforth.machine.InstructionPointerBuilder.anInstructionPointer;
 import static bjforth.machine.MachineAssertions.*;
 import static bjforth.machine.MachineBuilder.aMachine;
 import static bjforth.machine.MachineStateBuilder.aMachineState;
 import static bjforth.machine.MemoryBuilder.aMemory;
-import static bjforth.machine.NextInstructionPointerBuilder.aNextInstructionPointer;
 import static bjforth.machine.ParameterStackBuilder.aParameterStack;
 import static org.assertj.core.api.Assertions.*;
 
@@ -75,13 +73,7 @@ void worksOkWithNumbers(
 
     // THEN
     assertThat(actualState)
-        .hasInstructionPointerEqualTo(anInstructionPointer().with(referenceState).plus(1).build())
-        .hasNextInstructionPointerEqualTo(
-            aNextInstructionPointer().with(referenceState).plus(1).build())
-        .hasDictionaryEqualTo(referenceState)
-        .hasMemoryEqualTo(referenceState)
-        .hasParameterStackEqualTo(aParameterStack().with(expectedResult).build())
-        .hasReturnStackEqualTo(referenceState);
+        .hasParameterStackEqualTo(aParameterStack().with(expectedResult).build());
   }
 
   @DisplayName("should throw if any of parameter stack top is not a number.")

bjforth/src/test/java/bjforth/primitives/BASETest.java

@@ -19,12 +19,10 @@
 package bjforth.primitives;
 
 import static bjforth.machine.BootstrapUtils.getPrimitiveAddress;
-import static bjforth.machine.InstructionPointerBuilder.anInstructionPointer;
 import static bjforth.machine.MachineAssertions.assertThat;
 import static bjforth.machine.MachineBuilder.aMachine;
 import static bjforth.machine.MachineStateBuilder.aMachineState;
 import static bjforth.machine.MemoryBuilder.aMemory;
-import static bjforth.machine.NextInstructionPointerBuilder.aNextInstructionPointer;
 import static bjforth.machine.ParameterStackBuilder.aParameterStack;
 
 import bjforth.variables.Variables;
@@ -33,7 +31,7 @@
 
 class BASETest {
   @Test
-  @DisplayName("Push the value of HERE to parameter stack.")
+  @DisplayName("Push the value of BASE to parameter stack.")
   public void worksOk() {
     // GIVEN
     var BASEaddr = getPrimitiveAddress("BASE");
@@ -52,13 +50,6 @@ public void worksOk() {
     machine.step();
 
     // THEN
-    assertThat(actualState)
-        .hasInstructionPointerEqualTo(anInstructionPointer().with(referenceState).plus(1).build())
-        .hasNextInstructionPointerEqualTo(
-            aNextInstructionPointer().with(referenceState).plus(1).build())
-        .hasDictionaryEqualTo(referenceState)
-        .hasMemoryEqualTo(referenceState)
-        .hasParameterStackEqualTo(aParameterStack().with(10).build())
-        .hasReturnStackEqualTo(referenceState);
+    assertThat(actualState).hasParameterStackEqualTo(aParameterStack().with(10).build());
   }
 }

bjforth/src/test/java/bjforth/primitives/BRANCHTest.java

@@ -57,7 +57,7 @@ public void worksOk() {
     assertThat(actualState)
         .hasInstructionPointerEqualTo(anInstructionPointer().with(nip).plus(offset).build())
         .hasNextInstructionPointerEqualTo(
-            aNextInstructionPointer().with(referenceState).plus(offset).plus(1).build())
+            aNextInstructionPointer().with(referenceState).plus(offset).build())
         .hasMemoryEqualTo(referenceState)
         .hasParameterStackEqualTo(aParameterStack().build())
         .hasReturnStackEqualTo(referenceState);

bjforth/src/test/java/bjforth/primitives/CFATest.java

@@ -19,12 +19,10 @@
 package bjforth.primitives;
 
 import static bjforth.machine.BootstrapUtils.getPrimitiveAddress;
-import static bjforth.machine.InstructionPointerBuilder.anInstructionPointer;
 import static bjforth.machine.MachineAssertions.assertThat;
 import static bjforth.machine.MachineBuilder.aMachine;
 import static bjforth.machine.MachineStateBuilder.aMachineState;
 import static bjforth.machine.MemoryBuilder.aMemory;
-import static bjforth.machine.NextInstructionPointerBuilder.aNextInstructionPointer;
 import static bjforth.machine.ParameterStackBuilder.aParameterStack;
 import static org.apache.commons.lang3.RandomUtils.nextInt;
 import static org.junit.jupiter.api.Assertions.assertThrows;
@@ -55,13 +53,7 @@ public void worksOk() {
     machine.step();
 
     // THEN
-    assertThat(actualState)
-        .hasInstructionPointerEqualTo(anInstructionPointer().with(referenceState).plus(1).build())
-        .hasNextInstructionPointerEqualTo(
-            aNextInstructionPointer().with(referenceState).plus(1).build())
-        .hasMemoryEqualTo(referenceState)
-        .hasParameterStackEqualTo(aParameterStack().build())
-        .hasReturnStackEqualTo(referenceState);
+    assertThat(actualState).hasParameterStackEqualTo(aParameterStack().build());
   }
 
   @Test