Groovy example source code file (SourceCodeTraversal.java)

This example Groovy source code file (SourceCodeTraversal.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

arraylist, closure, f, f, foo, foo, groovysourceast, groovysourceast, mytype, object, sourcecodetraversal, sourcecodetraversal, string, traversalhelper, util

The Groovy SourceCodeTraversal.java source code

/*
 * Copyright 2003-2010 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.antlr.treewalker;

import java.util.ArrayList;
import java.util.Collections;

import org.codehaus.groovy.antlr.GroovySourceAST;
import org.codehaus.groovy.antlr.parser.GroovyTokenTypes;

/**
 * A treewalker for the antlr generated AST that attempts to visit the
 * AST nodes in the order needed to generate valid groovy source code.
 *
 * @author <a href="mailto:groovy@ross-rayner.com">Jeremy Rayner
 */
public class SourceCodeTraversal extends TraversalHelper {
    /**
     * Constructs a treewalker for the antlr generated AST that attempts to visit the
     * AST nodes in the order needed to generate valid groovy source code.
     * @param visitor the visitor implementation to call for each AST node.
     */
    public SourceCodeTraversal(Visitor visitor) {
        super(visitor);
    }

    /**
     * gather, sort and process all unvisited nodes
     * @param t the AST to process
     */
    public void setUp(GroovySourceAST t) {
        super.setUp(t);
        
        // gather and sort all unvisited AST nodes
        unvisitedNodes = new ArrayList<GroovySourceAST>();
        traverse(t);
        Collections.sort(unvisitedNodes);
    }

    /**
     * traverse an AST node
     * @param t the AST node to traverse
     */
    private void traverse(GroovySourceAST t) {
        if (t == null) { return; }
        if (unvisitedNodes != null) {
           unvisitedNodes.add(t);
        }
        GroovySourceAST child = (GroovySourceAST)t.getFirstChild();
        if (child != null) {
            traverse(child);
        }
        GroovySourceAST sibling = (GroovySourceAST)t.getNextSibling();
        if (sibling != null) {
            traverse(sibling);
        }
    }

    protected void accept(GroovySourceAST currentNode) {
        if (currentNode != null && unvisitedNodes != null && unvisitedNodes.size() > 0) {
            GroovySourceAST t = currentNode;

            if (!(unvisitedNodes.contains(currentNode))) {
                return;
            }
            push(t);
            switch (t.getType()) {
                case GroovyTokenTypes.QUESTION: // expr?foo:bar
                    accept_FirstChild_v_SecondChild_v_ThirdChild_v(t);
                    break;

                case GroovyTokenTypes.CASE_GROUP: //
                case GroovyTokenTypes.LITERAL_instanceof: // foo instanceof MyType
                    accept_FirstChild_v_SecondChildsChildren_v(t);
                    break;

                case GroovyTokenTypes.ANNOTATION:
                    accept_v_FirstChild_2ndv_SecondChild_v___LastChild_v(t);
                    break;

                case GroovyTokenTypes.CLOSURE_LIST: // (a=1; a<10; a++)
                case GroovyTokenTypes.ELIST: // a,b,c
                case GroovyTokenTypes.PARAMETERS: // a,b,c
                case GroovyTokenTypes.TYPE_ARGUMENTS: // <String, Object>
                case GroovyTokenTypes.STRING_CONSTRUCTOR: // "foo${bar}wibble"
                case GroovyTokenTypes.TYPE_PARAMETER: // class Foo<T extends F>
                case GroovyTokenTypes.TYPE_PARAMETERS: // class Foo<T>
                case GroovyTokenTypes.TYPE_UPPER_BOUNDS: // class Foo<T extends F>
                    accept_v_FirstChild_v_SecondChild_v___LastChild_v(t);
                    // todo : confirm that TYPE_LOWER_BOUNDS does not have multiple children
                    break;

                case GroovyTokenTypes.VARIABLE_PARAMETER_DEF: // void f(String ... others) {}
                    accept_v_FirstChild_SecondChild_v_ThirdChild_v(t);
                    break;

                case GroovyTokenTypes.INDEX_OP:
                    //accept_FirstChild_v_SecondChild_v(t);
                    accept_SecondChild_v_ThirdChild_v(t);
                    break;

                case GroovyTokenTypes.ENUM_CONSTANT_DEF: // enum Foo(THESE,ARE,THEY)
                case GroovyTokenTypes.EXPR:
                case GroovyTokenTypes.IMPORT:
                case GroovyTokenTypes.STATIC_IMPORT:
                case GroovyTokenTypes.VARIABLE_DEF:
                case GroovyTokenTypes.METHOD_DEF:
                case GroovyTokenTypes.OBJBLOCK: //class Foo {def bar()}  <-- this block
                case GroovyTokenTypes.PARAMETER_DEF: // void f(String me) {}
                case GroovyTokenTypes.SLIST: // list of expressions, variable defs etc
                    accept_v_AllChildren_v(t);
                    break;

                case GroovyTokenTypes.ANNOTATION_MEMBER_VALUE_PAIR: // @Blue(foo=123)
                case GroovyTokenTypes.ASSIGN: // a = b
                case GroovyTokenTypes.BAND_ASSIGN: // a &= b
                case GroovyTokenTypes.BOR_ASSIGN: // a |= b
                case GroovyTokenTypes.BSR_ASSIGN: // a >>>= b
                case GroovyTokenTypes.BXOR_ASSIGN: // a ^= b
                case GroovyTokenTypes.COMPARE_TO: // a <=> b
                case GroovyTokenTypes.DIV_ASSIGN: // a /= b
                case GroovyTokenTypes.EQUAL: // a == b
                case GroovyTokenTypes.MINUS_ASSIGN: // a -= b
                case GroovyTokenTypes.MOD_ASSIGN: // a %= b
                case GroovyTokenTypes.NOT_EQUAL: // a != b
                case GroovyTokenTypes.PLUS_ASSIGN: // a += b
                case GroovyTokenTypes.REGEX_FIND: // a =~ b
                case GroovyTokenTypes.REGEX_MATCH: // a ==~ b
                case GroovyTokenTypes.SL_ASSIGN: // a <<= b
                case GroovyTokenTypes.SR_ASSIGN: // a >>= b
                case GroovyTokenTypes.STAR_ASSIGN: // a *= b
                case GroovyTokenTypes.STAR_STAR_ASSIGN: // x **= 3
                    if (t.childAt(1) != null) {
                        accept_FirstChild_v_RestOfTheChildren(t);
                    } else {
                        accept_v_FirstChild_v_RestOfTheChildren(t);
                    }
                    break;

                case GroovyTokenTypes.ANNOTATION_FIELD_DEF: // @interface Foo{ int bar()...
                    accept_FirstSecondAndThirdChild_v_v_ForthChild(t);
                    break;
                    
                case GroovyTokenTypes.ANNOTATION_DEF: // @interface Foo...
                case GroovyTokenTypes.BAND: // 1 & 2
                case GroovyTokenTypes.BOR: // 1 | 2
                case GroovyTokenTypes.BSR: // 1 >>> 2
                case GroovyTokenTypes.BXOR: // 1 ^ 2
                case GroovyTokenTypes.CLASS_DEF: // class Foo...
                case GroovyTokenTypes.CTOR_IDENT: // private Foo() {...
                case GroovyTokenTypes.DIV: //  3/4
                case GroovyTokenTypes.DOT: // foo.bar
                case GroovyTokenTypes.ENUM_DEF: // enum Foo...
                case GroovyTokenTypes.GE: // a >= b
                case GroovyTokenTypes.GT: // a > b
                case GroovyTokenTypes.INTERFACE_DEF: // interface Foo...
                case GroovyTokenTypes.LABELED_ARG: // myMethod(name:"Jez")
                case GroovyTokenTypes.LABELED_STAT: // foo:x=1                        
                case GroovyTokenTypes.LAND: // true && false
                case GroovyTokenTypes.LE: // a <= b
                case GroovyTokenTypes.LITERAL_as: // foo as Bar
                case GroovyTokenTypes.LITERAL_in: // if (i in myList) ...
                case GroovyTokenTypes.LOR: // true && false
                case GroovyTokenTypes.LT: // a < b
                case GroovyTokenTypes.MEMBER_POINTER: // this.&foo()
                case GroovyTokenTypes.MOD: //  4 % 3
                case GroovyTokenTypes.MINUS: // 1 - 1
                case GroovyTokenTypes.OPTIONAL_DOT: // foo?.bar
                case GroovyTokenTypes.PACKAGE_DEF:
                case GroovyTokenTypes.PLUS: // 1 + 1
                case GroovyTokenTypes.RANGE_EXCLUSIVE: // [1..<10]
                case GroovyTokenTypes.RANGE_INCLUSIVE: // [1..10]
                case GroovyTokenTypes.SL: // a << b
                case GroovyTokenTypes.SPREAD_DOT: // foo*.bar
                case GroovyTokenTypes.SR: // a >> b
                case GroovyTokenTypes.STAR: // a * b   or    import foo.*
                case GroovyTokenTypes.STAR_STAR: // x ** 3
                    accept_FirstChild_v_RestOfTheChildren(t);
                    break;

                case GroovyTokenTypes.CTOR_CALL:
                case GroovyTokenTypes.METHOD_CALL:
                    if (t.getNumberOfChildren() == 2 && t.childAt(1) != null && t.childAt(1).getType() == GroovyTokenTypes.CLOSABLE_BLOCK) {
                        // myMethod {...
                        accept_FirstChild_v_SecondChild(t);
                    } else {
                        GroovySourceAST lastChild = t.childAt(t.getNumberOfChildren() -1);
                        if (lastChild != null && lastChild.getType() == GroovyTokenTypes.CLOSABLE_BLOCK) {
                            // myMethod(a,b) {...
                            accept_FirstChild_v_RestOfTheChildren_v_LastChild(t);
                        } else {
                            // myMethod(a,b)
                            accept_FirstChild_v_RestOfTheChildren_v(t);
                        }
                    }
                    break;

                case GroovyTokenTypes.LITERAL_while:
//deprecated                case GroovyTokenTypes.LITERAL_with:
                case GroovyTokenTypes.TYPECAST: // (String)itr.next()
                    accept_v_FirstChildsFirstChild_v_RestOfTheChildren(t);
                    break;

                case GroovyTokenTypes.LITERAL_if: // if (grandchild) {child1} else {child2} ...
                    accept_v_FirstChildsFirstChild_v_Child2_Child3_v_Child4_v___v_LastChild(t);
                    break;

                case GroovyTokenTypes.CLOSABLE_BLOCK: // [1,2,3].each {foo(it)}  <-- Closure
                    if (t.childAt(0) != null && t.childAt(0).getType() == GroovyTokenTypes.IMPLICIT_PARAMETERS) {
                        accept_v_AllChildren_v(t);
                    } else {
                        accept_v_FirstChild_v_RestOfTheChildren_v(t);
                    }
                    break;

                case GroovyTokenTypes.FOR_IN_ITERABLE:
                case GroovyTokenTypes.LITERAL_for:
                case GroovyTokenTypes.LITERAL_new:
                case GroovyTokenTypes.LITERAL_switch:
                    accept_v_FirstChild_v_RestOfTheChildren_v(t);
                    break;
 
                case GroovyTokenTypes.ANNOTATIONS: // just like modifiers but for package/enum declarations
                case GroovyTokenTypes.LITERAL_assert:
                case GroovyTokenTypes.LITERAL_catch:
                case GroovyTokenTypes.LITERAL_synchronized:
                case GroovyTokenTypes.LITERAL_try:
                case GroovyTokenTypes.MODIFIERS:
                    accept_v_FirstChild_v_RestOfTheChildren(t);
                    break;
                    
                case GroovyTokenTypes.WILDCARD_TYPE:
                    accept_v_Siblings_v(t);
                    break;

                default:
                    accept_v_FirstChild_v(t);
                    break;
            }
            pop();
        }
    }
}