feat(#376): Towards Agent Base Acrhitecture

pom.xml

@@ -337,7 +337,7 @@ SOFTWARE.
                         <limit>
                           <counter>CLASS</counter>
                           <value>MISSEDCOUNT</value>
-                          <maximum>7</maximum>
+                          <maximum>8</maximum>
                         </limit>
                       </limits>
                     </rule>

src/main/java/org/eolang/opeo/SelectiveDecompiler.java

@@ -31,7 +31,7 @@
 import java.util.stream.Collectors;
 import org.eolang.opeo.decompilation.Decompiler;
 import org.eolang.opeo.decompilation.WithoutAliases;
-import org.eolang.opeo.decompilation.handlers.RouterHandler;
+import org.eolang.opeo.decompilation.agents.AllAgents;
 import org.eolang.opeo.jeo.JeoDecompiler;
 import org.eolang.opeo.storage.FileStorage;
 import org.eolang.opeo.storage.Storage;
@@ -41,7 +41,7 @@
  * Selective decompiler.
  * Decompiler that decompiles ONLY fully understandable methods.
  * These methods contain only instructions that are
- * supported by {@link org.eolang.opeo.decompilation.handlers.RouterHandler}.
+ * supported by {@link AllAgents}.
  *
  * @since 0.1
  */
@@ -69,7 +69,7 @@ public final class SelectiveDecompiler implements Decompiler {
      * @param modified Folder where to save the modified XMIRs.
      */
     public SelectiveDecompiler(final Path input, final Path output, final Path modified) {
-        this(input, output, modified, new RouterHandler(false).supportedOpcodes());
+        this(input, output, modified, new AllAgents(false).supportedOpcodes());
     }
 
     /**
@@ -97,7 +97,7 @@ public SelectiveDecompiler(
     public SelectiveDecompiler(
         final Storage storage, final Storage modified
     ) {
-        this(storage, modified, new RouterHandler(false).supportedOpcodes());
+        this(storage, modified, new AllAgents(false).supportedOpcodes());
     }
 
     /**

src/main/java/org/eolang/opeo/ast/Add.java → src/main/java/org/eolang/opeo/ast/Addition.java

@@ -41,7 +41,7 @@
  */
 @EqualsAndHashCode
 @ToString
-public final class Add implements AstNode, Typed {
+public final class Addition implements AstNode, Typed {
 
     /**
      * Left operand.
@@ -58,7 +58,7 @@ public final class Add implements AstNode, Typed {
      * @param node XML node
      * @param parser Parser
      */
-    public Add(final XmlNode node, final Function<XmlNode, AstNode> parser) {
+    public Addition(final XmlNode node, final Function<XmlNode, AstNode> parser) {
         this(
             parser.apply(node.children().collect(Collectors.toList()).get(0)),
             parser.apply(node.children().collect(Collectors.toList()).get(1))
@@ -70,7 +70,7 @@ public Add(final XmlNode node, final Function<XmlNode, AstNode> parser) {
      * @param left Left operand
      * @param right Right operand
      */
-    public Add(final AstNode left, final AstNode right) {
+    public Addition(final AstNode left, final AstNode right) {
         this.left = left;
         this.right = right;
     }

src/main/java/org/eolang/opeo/ast/Labeled.java

@@ -30,6 +30,7 @@
 import lombok.EqualsAndHashCode;
 import lombok.ToString;
 import org.eolang.jeo.representation.xmir.XmlNode;
+import org.eolang.opeo.decompilation.agents.InvokespecialAgent;
 import org.objectweb.asm.Type;
 import org.xembly.Directive;
 import org.xembly.Directives;
@@ -39,7 +40,7 @@
  * This class needed to avoid considering labels as separate nodes.
  * Maybe it's wrong to do so, but it's easier to implement this way, at least for now.
  * Pay attention, that {@link Labeled} class violates class hierarchy.
- * It is the most visible within {@link org.eolang.opeo.decompilation.handlers.InvokespecialHandler}
+ * It is the most visible within {@link InvokespecialAgent}
  * implementation.
  * @since 0.2
  */

src/main/java/org/eolang/opeo/ast/Opcode.java

@@ -35,6 +35,7 @@
 import org.eolang.jeo.representation.xmir.XmlInstruction;
 import org.eolang.jeo.representation.xmir.XmlNode;
 import org.eolang.jeo.representation.xmir.XmlOperand;
+import org.eolang.opeo.Instruction;
 import org.xembly.Directive;
 
 /**
@@ -119,6 +120,10 @@ public Opcode(final XmlInstruction instruction) {
         );
     }
 
+    public Opcode(final Instruction instruction) {
+        this(instruction.opcode(), instruction.operands());
+    }
+
     /**
      * Constructor.
      * @param bytecode Bytecode
@@ -141,6 +146,40 @@ public List<AstNode> opcodes() {
         return Arrays.asList(this);
     }
 
+    /**
+     * Opcode number.
+     * @return Opcode number.
+     */
+    public int opcode() {
+        return this.bytecode;
+    }
+
+    /**
+     * Opcode operands.
+     * @return Opcode operands.
+     */
+    public List<Object> params() {
+        return this.operands;
+    }
+
+    /**
+     * Instruction operand.
+     * @param index Operand index.
+     * @return Instruction operand.
+     */
+    public Object operand(final int index) {
+        if (this.operands.size() <= index) {
+            throw new IllegalStateException(
+                String.format(
+                    "Instruction '%s' doesn't have operand at index '%d'",
+                    this,
+                    index
+                )
+            );
+        }
+        return this.operands.get(index);
+    }
+
     /**
      * Disable opcodes counting.
      * It is useful for tests.

src/main/java/org/eolang/opeo/compilation/SelectiveCompiler.java

@@ -27,7 +27,7 @@
 import java.nio.file.Path;
 import java.util.Arrays;
 import java.util.stream.Collectors;
-import org.eolang.opeo.decompilation.handlers.RouterHandler;
+import org.eolang.opeo.decompilation.agents.AllAgents;
 import org.eolang.opeo.storage.CompilationStorage;
 import org.eolang.opeo.storage.Storage;
 import org.eolang.opeo.storage.XmirEntry;
@@ -65,7 +65,7 @@ public SelectiveCompiler(final Path xmirs, final Path output) {
      */
     public SelectiveCompiler(final Storage storage) {
         this.storage = storage;
-        this.supported = new RouterHandler(false).supportedOpcodes();
+        this.supported = new AllAgents(false).supportedOpcodes();
     }
 
     @Override

src/main/java/org/eolang/opeo/compilation/XmirParser.java

@@ -27,7 +27,7 @@
 import java.util.List;
 import java.util.stream.Collectors;
 import org.eolang.jeo.representation.xmir.XmlNode;
-import org.eolang.opeo.ast.Add;
+import org.eolang.opeo.ast.Addition;
 import org.eolang.opeo.ast.ArrayConstructor;
 import org.eolang.opeo.ast.AstNode;
 import org.eolang.opeo.ast.Attributes;
@@ -136,7 +136,7 @@ public AstNode parse(final XmlNode node) {
         } else if ("duplicated".equals(base)) {
             result = new Duplicate(this.parse(node.firstChild()));
         } else if (".plus".equals(base)) {
-            result = new Add(node, this::parse);
+            result = new Addition(node, this::parse);
         } else if (".minus".equals(base)) {
             result = new Substraction(node, this::parse);
         } else if ("cast".equals(base)) {

src/main/java/org/eolang/opeo/decompilation/InstructionHandler.java → src/main/java/org/eolang/opeo/decompilation/DecompilationAgent.java

@@ -24,15 +24,15 @@
 package org.eolang.opeo.decompilation;
 
 /**
- * Instruction handler.
+ * An agent that tries to understand the current decompilation state and apply some changes to it.
  * @since 0.1
  */
 @FunctionalInterface
-public interface InstructionHandler {
+public interface DecompilationAgent {
 
     /**
-     * Handle instruction.
-     * @param state Current instruction to handle together with operand stack and variables.
+     * Handle the current state.
+     * @param state Current state to handle together with operand stack and variables.
      */
     void handle(DecompilerState state);
 }

src/main/java/org/eolang/opeo/decompilation/DecompilerMachine.java

@@ -25,11 +25,14 @@
 
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.LinkedList;
 import java.util.Map;
+import java.util.stream.Collectors;
 import org.cactoos.list.ListOf;
 import org.eolang.opeo.Instruction;
+import org.eolang.opeo.ast.Opcode;
 import org.eolang.opeo.ast.Root;
-import org.eolang.opeo.decompilation.handlers.RouterHandler;
+import org.eolang.opeo.decompilation.agents.AllAgents;
 import org.xembly.Directive;
 
 /**
@@ -47,7 +50,7 @@ public final class DecompilerMachine {
     /**
      * Handler that redirects instructions.
      */
-    private final RouterHandler router;
+    private final AllAgents agents;
 
     /**
      * Constructor.
@@ -73,7 +76,7 @@ public final class DecompilerMachine {
      */
     public DecompilerMachine(final LocalVariables locals, final Map<String, String> arguments) {
         this.locals = locals;
-        this.router = new RouterHandler(
+        this.agents = new AllAgents(
             "true".equals(arguments.getOrDefault("counting", "true"))
         );
     }
@@ -85,10 +88,15 @@ public DecompilerMachine(final LocalVariables locals, final Map<String, String>
      * @return Decompiled instructions.
      */
     public Iterable<Directive> decompile(final Instruction... instructions) {
-        final DecompilerState state = new DecompilerState(this.locals);
-        Arrays.stream(instructions)
-            .forEach(inst -> this.router.handle(state.next(inst)));
-        return new Root(new ListOf<>(state.stack().descendingIterator())).toXmir();
+        final DecompilerState initial = new DecompilerState(
+            Arrays.stream(instructions)
+                .map(Opcode::new)
+                .collect(Collectors.toCollection(LinkedList::new)),
+            new OperandStack(),
+            this.locals
+        );
+        this.agents.handle(initial);
+        return new Root(new ListOf<>(initial.stack().descendingIterator())).toXmir();
     }
 }