Node Framework

/**
 * Base class for all nodes in a Truffle AST
 * Provides tree structure, source information, and optimization hooks
 */
public abstract class Node implements NodeInterface, Cloneable {
    /** Returns the parent node or null for root */
    public final Node getParent();
    
    /** Returns all child nodes */
    public final Iterable<Node> getChildren();
    
    /** Replaces this node with another node */
    public final <T extends Node> T replace(T newNode);
    
    /** Replaces this node with another node and reason */
    public final <T extends Node> T replace(T newNode, CharSequence reason);
    
    /** Checks if this node can be replaced */
    public boolean isReplaceable();
    
    /** Returns a deep copy of this node */
    public Node deepCopy();
    
    /** Returns a copy of this node */
    public Node copy();
    
    /** Accepts a node visitor */
    public void accept(NodeVisitor visitor);
    
    /** Returns the source section for this node */
    public SourceSection getSourceSection();
    
    /** Checks if source section is available */
    public final boolean hasSourceSection();
    
    /** Returns a string representation of the source location */
    public final String getSourceLocation();
    
    /** Returns the root node of this AST */
    public final RootNode getRootNode();
    
    /** Returns the language info for this node's language */
    public final LanguageInfo getLanguage();
    
    /** Notifies that this node was adopted into an AST */
    protected void onReplace(Node newNode, CharSequence reason) {
        // Default implementation does nothing
    }
    
    /**
     * Returns a cost estimate for this node
     * Used by the runtime for compilation heuristics
     */
    public NodeCost getCost() {
        return NodeCost.MONOMORPHIC;
    }
    
    /**
     * Returns debug information about this node
     */
    protected Object getDebugProperties() {
        return null;
    }
}

/**
 * Root node of a Truffle AST representing an executable unit
 * Entry point for method/function execution
 */
public abstract class RootNode extends Node {
    /** 
     * Executes this root node with the given frame
     * @param frame Execution frame containing arguments and local variables
     * @return Execution result
     */
    public abstract Object execute(VirtualFrame frame);
    
    /** Returns the language info for this root node */
    public final LanguageInfo getLanguageInfo();
    
    /** Returns the call target for this root node */
    public final CallTarget getCallTarget();
    
    /** Returns the frame descriptor for this root node */
    public final FrameDescriptor getFrameDescriptor();
    
    /**
     * Returns the name of this executable unit
     * Used for debugging and profiling
     */
    public String getName() {
        return "Unnamed";
    }
    
    /**
     * Returns a qualified name including module/class information
     */
    public String getQualifiedName() {
        return getName();
    }
    
    /**
     * Checks if this root node represents internal code
     * Internal code is excluded from stack traces by default
     */
    public boolean isInternal() {
        return false;
    }
    
    /**
     * Checks if this root node can be cloned for splitting
     */
    public boolean isCloningAllowed() {
        return true;
    }
    
    /**
     * Creates a split version of this root node
     */
    public RootNode split() {
        return cloneUninitializedRootNode();
    }
    
    /**
     * Checks if this root node represents a tail call position
     */
    public boolean isTail() {
        return true;
    }
    
    /**
     * Returns debug information for this root node
     */
    protected Object getDebugInfo() {
        return null;
    }
}

import com.oracle.truffle.api.frame.VirtualFrame;
import com.oracle.truffle.api.nodes.RootNode;

public class MyLanguageFunctionRootNode extends RootNode {
    @Child private MyLanguageStatementNode bodyNode;
    private final String functionName;
    
    public MyLanguageFunctionRootNode(LanguageInfo language, FrameDescriptor frameDescriptor, 
                                     MyLanguageStatementNode bodyNode, String functionName) {
        super(language, frameDescriptor);
        this.bodyNode = bodyNode;
        this.functionName = functionName;
    }
    
    @Override
    public Object execute(VirtualFrame frame) {
        try {
            return bodyNode.execute(frame);
        } catch (MyLanguageReturnException returnEx) {
            return returnEx.getReturnValue();
        }
    }
    
    @Override
    public String getName() {
        return functionName;
    }
    
    @Override
    public boolean isInternal() {
        return functionName.startsWith("__");
    }
}

/**
 * Optimized call node for direct calls to a known call target
 * Provides better performance than indirect calls when target is known
 */
public abstract class DirectCallNode extends Node {
    /** Creates a direct call node for the given call target */
    public static DirectCallNode create(CallTarget callTarget);
    
    /** Calls the target with the given arguments */
    public abstract Object call(Object... arguments);
    
    /** Returns the call target */
    public abstract CallTarget getCallTarget();
    
    /** 
     * Checks if this call can be inlined
     * Inlining provides better optimization opportunities
     */
    public abstract boolean isInlinable();
    
    /** 
     * Checks if calls should be inlined 
     * Returns true if inlining is beneficial
     */
    public abstract boolean isInliningForced();
    
    /**
     * Forces or prevents inlining of this call
     */
    public abstract void forceInlining();
    
    /**
     * Returns the current call target, accounting for splitting
     */
    public abstract CallTarget getCurrentCallTarget();
    
    /**
     * Returns the original call target before any splitting
     */
    public abstract CallTarget getClonedCallTarget();
}

/**
 * Call node for indirect calls where target is determined at runtime
 * Less optimized than direct calls but supports dynamic dispatch
 */
public abstract class IndirectCallNode extends Node {
    /** Creates an indirect call node */
    public static IndirectCallNode create();
    
    /** Calls the given call target with arguments */
    public abstract Object call(CallTarget callTarget, Object... arguments);
}

/**
 * Marks a field as a child node
 * Child nodes are automatically adopted and included in tree operations
 */
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Child {
}

/**
 * Marks a field as containing child nodes
 * Used for arrays or collections of child nodes
 */
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Children {
}

/**
 * Node cost enumeration for optimization heuristics
 */
public enum NodeCost {
    /** Uninitialized node - has not executed yet */
    UNINITIALIZED,
    
    /** Monomorphic node - handles one type efficiently */
    MONOMORPHIC,
    
    /** Polymorphic node - handles multiple types with some overhead */
    POLYMORPHIC,
    
    /** Megamorphic node - handles many types with significant overhead */
    MEGAMORPHIC,
    
    /** Invalid node - should be replaced */
    INVALID
}

/**
 * Visitor interface for traversing node trees
 */
public interface NodeVisitor {
    /** 
     * Visits a node
     * @param node The node being visited
     * @return true to continue visiting children, false to skip
     */
    boolean visit(Node node);
}

/**
 * Utility class for node tree operations
 */
public final class NodeUtil {
    /** Finds all nodes of a specific type in the tree */
    public static <T> List<T> findAllNodeInstances(Node root, Class<T> clazz);
    
    /** Finds the first node of a specific type */
    public static <T> T findFirstNodeInstance(Node root, Class<T> clazz);
    
    /** Counts nodes in the tree */
    public static int countNodes(Node root);
    
    /** Creates a tree representation string */
    public static String printTreeToString(Node root);
    
    /** Dumps the tree structure to output */
    public static void printTree(Node root);
    
    /** Verifies tree structure integrity */
    public static boolean verify(Node root);
    
    /** Returns all parent nodes up to root */
    public static List<Node> collectParents(Node node);
}

/**
 * Interface for optimized loop execution
 */
public interface LoopNode extends Node.Child {
    /** Executes the loop */
    void execute(VirtualFrame frame);
    
    /** Returns the repeating node executed in the loop */
    RepeatingNode getRepeatingNode();
}

/**
 * Interface for nodes that repeat in a loop
 */
public interface RepeatingNode extends Node.Child {
    /** 
     * Executes one iteration of the loop
     * @param frame Current execution frame
     * @return true to continue looping, false to exit
     */
    boolean executeRepeating(VirtualFrame frame);
}

/**
 * Factory for creating loop nodes
 */
public final class Truffle {
    /** Creates an optimized loop node */
    public static LoopNode createLoopNode(RepeatingNode repeatingNode);
}

// Creating a specialized node with child nodes
public abstract class MyLanguageBinaryOpNode extends MyLanguageExpressionNode {
    @Child private MyLanguageExpressionNode leftNode;
    @Child private MyLanguageExpressionNode rightNode;
    
    public MyLanguageBinaryOpNode(MyLanguageExpressionNode left, MyLanguageExpressionNode right) {
        this.leftNode = left;
        this.rightNode = right;
    }
    
    @Override
    public final Object execute(VirtualFrame frame) {
        Object leftValue = leftNode.execute(frame);
        Object rightValue = rightNode.execute(frame);
        return execute(leftValue, rightValue);
    }
    
    protected abstract Object execute(Object left, Object right);
}

// Using loop nodes for optimized iteration
public class MyLanguageWhileNode extends MyLanguageStatementNode {
    @Child private MyLanguageExpressionNode conditionNode;
    @Child private LoopNode loopNode;
    
    public MyLanguageWhileNode(MyLanguageExpressionNode condition, MyLanguageStatementNode body) {
        this.conditionNode = condition;
        this.loopNode = Truffle.createLoopNode(new MyLanguageWhileRepeatingNode(condition, body));
    }
    
    @Override
    public Object execute(VirtualFrame frame) {
        loopNode.execute(frame);
        return MyLanguageNull.INSTANCE;
    }
    
    private static class MyLanguageWhileRepeatingNode extends Node implements RepeatingNode {
        @Child private MyLanguageExpressionNode conditionNode;
        @Child private MyLanguageStatementNode bodyNode;
        
        @Override
        public boolean executeRepeating(VirtualFrame frame) {
            if (!isTruthy(conditionNode.execute(frame))) {
                return false; // Exit loop
            }
            
            try {
                bodyNode.execute(frame);
                return true; // Continue loop
            } catch (MyLanguageBreakException e) {
                return false; // Break statement
            }
        }
    }
}

public interface NodeInterface {
    /** Base interface implemented by all nodes */
}

public final class SourceSection {
    /** Returns the source object */
    public Source getSource();
    
    /** Checks if this section is available */
    public boolean isAvailable();
    
    /** Returns the start line (1-based) */
    public int getStartLine();
    
    /** Returns the start column (1-based) */  
    public int getStartColumn();
    
    /** Returns the end line (1-based) */
    public int getEndLine();
    
    /** Returns the end column (1-based) */
    public int getEndColumn();
    
    /** Returns the character index (0-based) */
    public int getCharIndex();
    
    /** Returns the character length */
    public int getCharLength();
    
    /** Returns the characters in this section */
    public CharSequence getCharacters();
}

public abstract class CallTarget {
    /** Calls this target with the given arguments */
    public abstract Object call(Object... arguments);
}