Groovy example source code file (TupleConstructorASTTransformation.java)

This example Groovy source code file (TupleConstructorASTTransformation.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

annotatednode, annotationnode, arraylist, arraylist, classnode, classnode, constantexpression, expression, list, list, my_type_name, string, string, util, variableexpression

The Groovy TupleConstructorASTTransformation.java source code

/*
 * Copyright 2008-2011 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.codehaus.groovy.transform;

import groovy.transform.TupleConstructor;
import org.codehaus.groovy.ast.ASTNode;
import org.codehaus.groovy.ast.AnnotatedNode;
import org.codehaus.groovy.ast.AnnotationNode;
import org.codehaus.groovy.ast.ClassHelper;
import org.codehaus.groovy.ast.ClassNode;
import org.codehaus.groovy.ast.ConstructorNode;
import org.codehaus.groovy.ast.FieldNode;
import org.codehaus.groovy.ast.Parameter;
import org.codehaus.groovy.ast.expr.ArgumentListExpression;
import org.codehaus.groovy.ast.expr.ConstantExpression;
import org.codehaus.groovy.ast.expr.ConstructorCallExpression;
import org.codehaus.groovy.ast.expr.Expression;
import org.codehaus.groovy.ast.expr.PropertyExpression;
import org.codehaus.groovy.ast.expr.VariableExpression;
import org.codehaus.groovy.ast.stmt.BlockStatement;
import org.codehaus.groovy.ast.stmt.ExpressionStatement;
import org.codehaus.groovy.control.CompilePhase;
import org.codehaus.groovy.control.SourceUnit;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import static org.codehaus.groovy.transform.AbstractASTTransformUtil.*;

/**
 * Handles generation of code for the @TupleConstructor annotation.
 *
 * @author Paul King
 */
@GroovyASTTransformation(phase = CompilePhase.CANONICALIZATION)
public class TupleConstructorASTTransformation extends AbstractASTTransformation {

    static final Class MY_CLASS = TupleConstructor.class;
    static final ClassNode MY_TYPE = ClassHelper.make(MY_CLASS);
    static final String MY_TYPE_NAME = "@" + MY_TYPE.getNameWithoutPackage();
    private static Map<Class primitivesInitialValues;

    static {
        final ConstantExpression zero = new ConstantExpression(0);
        final ConstantExpression zeroDecimal = new ConstantExpression(.0);
        primitivesInitialValues = new HashMap<Class();
        primitivesInitialValues.put(int.class, zero);
        primitivesInitialValues.put(long.class, zero);
        primitivesInitialValues.put(short.class, zero);
        primitivesInitialValues.put(byte.class, zero);
        primitivesInitialValues.put(char.class, zero);
        primitivesInitialValues.put(float.class, zeroDecimal);
        primitivesInitialValues.put(double.class, zeroDecimal);
        primitivesInitialValues.put(boolean.class, ConstantExpression.FALSE);
    }

    public void visit(ASTNode[] nodes, SourceUnit source) {
        init(nodes, source);
        AnnotatedNode parent = (AnnotatedNode) nodes[1];
        AnnotationNode anno = (AnnotationNode) nodes[0];
        if (!MY_TYPE.equals(anno.getClassNode())) return;

        if (parent instanceof ClassNode) {
            ClassNode cNode = (ClassNode) parent;
            checkNotInterface(cNode, MY_TYPE_NAME);
            boolean includeFields = memberHasValue(anno, "includeFields", true);
            boolean includeProperties = !memberHasValue(anno, "includeProperties", false);
            boolean includeSuperFields = memberHasValue(anno, "includeSuperFields", true);
            boolean includeSuperProperties = memberHasValue(anno, "includeSuperProperties", true);
            boolean callSuper = memberHasValue(anno, "callSuper", true);
            boolean force = memberHasValue(anno, "force", true);
            List<String> excludes = tokenize((String) getMemberValue(anno, "excludes"));
            List<String> includes = tokenize((String) getMemberValue(anno, "includes"));
            if (hasAnnotation(cNode, CanonicalASTTransformation.MY_TYPE)) {
                AnnotationNode canonical = cNode.getAnnotations(CanonicalASTTransformation.MY_TYPE).get(0);
                if (excludes == null || excludes.isEmpty()) excludes = tokenize((String) getMemberValue(canonical, "excludes"));
                if (includes == null || includes.isEmpty()) includes = tokenize((String) getMemberValue(canonical, "includes"));
            }
            if (includes != null && !includes.isEmpty() && excludes != null && !excludes.isEmpty()) {
                addError("Error during " + MY_TYPE_NAME + " processing: Only one of 'includes' and 'excludes' should be supplied not both.", anno);
            }
            createConstructor(cNode, includeFields, includeProperties, includeSuperFields, includeSuperProperties, callSuper, force, excludes, includes);
        }
    }

    public static void createConstructor(ClassNode cNode, boolean includeFields, boolean includeProperties, boolean includeSuperFields, boolean includeSuperProperties, boolean callSuper, boolean force, List<String> excludes, List includes) {
        // no processing if existing constructors found
        List<ConstructorNode> constructors = cNode.getDeclaredConstructors();
        if (constructors.size() > 1 && !force) return;
        boolean foundEmpty = constructors.size() == 1 && constructors.get(0).getFirstStatement() == null;
        if (constructors.size() == 1 && !foundEmpty && !force) return;
        // HACK: JavaStubGenerator could have snuck in a constructor we don't want
        if (foundEmpty) constructors.remove(0);

        List<FieldNode> superList = new ArrayList();
        if (includeSuperProperties) {
            superList.addAll(getSuperPropertyFields(cNode.getSuperClass()));
        }
        if (includeSuperFields) {
            superList.addAll(getSuperNonPropertyFields(cNode.getSuperClass()));
        }

        List<FieldNode> list = new ArrayList();
        if (includeProperties) {
            list.addAll(getInstancePropertyFields(cNode));
        }
        if (includeFields) {
            list.addAll(getInstanceNonPropertyFields(cNode));
        }

        final List<Parameter> params = new ArrayList();
        final List<Expression> superParams = new ArrayList();
        final BlockStatement body = new BlockStatement();
        for (FieldNode fNode : superList) {
            String name = fNode.getName();
            if (shouldSkip(name, excludes, includes)) continue;
            params.add(createParam(fNode, name));
            if (callSuper) {
                superParams.add(new VariableExpression(name));
            } else {
                body.addStatement(assignStatement(new PropertyExpression(VariableExpression.THIS_EXPRESSION, name), new VariableExpression(name)));
            }
        }
        if (callSuper) {
            body.addStatement(new ExpressionStatement(new ConstructorCallExpression(ClassNode.SUPER, new ArgumentListExpression(superParams))));
        }
        for (FieldNode fNode : list) {
            String name = fNode.getName();
            if (shouldSkip(name, excludes, includes)) continue;
            params.add(createParam(fNode, name));
            body.addStatement(assignStatement(new PropertyExpression(VariableExpression.THIS_EXPRESSION, name), new VariableExpression(name)));
        }
        cNode.addConstructor(new ConstructorNode(ACC_PUBLIC, params.toArray(new Parameter[params.size()]), ClassNode.EMPTY_ARRAY, body));
    }

    private static Parameter createParam(FieldNode fNode, String name) {
        Parameter param = new Parameter(fNode.getType(), name);
        param.setInitialExpression(providedOrDefaultInitialValue(fNode));
        return param;
    }

    private static boolean shouldSkip(String name, List<String> excludes, List includes) {
        return (excludes != null && excludes.contains(name)) || name.contains("$") || (includes != null && !includes.isEmpty() && !includes.contains(name));
    }

    private static Expression providedOrDefaultInitialValue(FieldNode fNode) {
        Expression initialExp = fNode.getInitialExpression() != null ? fNode.getInitialExpression() : ConstantExpression.NULL;
        final ClassNode paramType = fNode.getType();
        if (ClassHelper.isPrimitiveType(paramType) && initialExp.equals(ConstantExpression.NULL)) {
            initialExp = primitivesInitialValues.get(paramType.getTypeClass());
        }
        return initialExp;
    }

}