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/*
 * Copyright 2003-2013 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 groovy.transform.stc;

import org.codehaus.groovy.ast.ASTNode;
import org.codehaus.groovy.ast.ClassNode;
import org.codehaus.groovy.ast.MethodNode;
import org.codehaus.groovy.control.CompilationUnit;
import org.codehaus.groovy.control.SourceUnit;

/**
 * 

Base class for hints which use the type of a parameter of the annotated method as the signature. * This can optionally use a generic type of the selected parameter as the hint. For example, imagine the following * method:

* void foo(A firstArg, B secondArg, Closure c) {...} *

If the c closure should be { B it -> ...}, then we can see that the parameter type * should be picked from the second parameter of the foo method, which is what {@link groovy.transform.stc.PickAnyArgumentHint} * lets you do.

*

Alternatively, the method may look like this:

* void <T> foo(A<T> firstArg, B secondArg, Closure c) {...} *

in which case if you want to express the fact that c should accept a <T> then you can use the * {@link #genericTypeIndex} value.

*

*

This class is extended by several hint providers that make it easier to use as annotation values.

* * @author Cédric Champeau * @since 2.3.0 */ public class PickAnyArgumentHint extends SingleSignatureClosureHint { private final int parameterIndex; private final int genericTypeIndex; /** * Creates the an argument picker which extracts the type of the first parameter. */ public PickAnyArgumentHint() { this(0,-1); } /** * Creates a picker which will extract the parameterIndex-th parameter type, or its * genericTypeIndex-th generic type genericTypeIndex is >=0. * @param parameterIndex the index of the parameter from which to extract the type * @param genericTypeIndex if >=0, then returns the corresponding generic type instead of the parameter type. */ public PickAnyArgumentHint(final int parameterIndex, final int genericTypeIndex) { this.parameterIndex = parameterIndex; this.genericTypeIndex = genericTypeIndex; } @Override public ClassNode[] getParameterTypes(final MethodNode node, final String[] options, final SourceUnit sourceUnit, final CompilationUnit unit, final ASTNode usage) { ClassNode type = node.getParameters()[parameterIndex].getOriginType(); if (genericTypeIndex>=0) { type = pickGenericType(type, genericTypeIndex); } return new ClassNode[]{type}; } }




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