PsiLambdaExpressionImpl.java

/*
 * Copyright 2000-2012 JetBrains s.r.o.
 *
 * 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 com.intellij.psi.impl.source.tree.java;

import com.intellij.lang.ASTNode;
import com.intellij.psi.*;
import com.intellij.psi.controlFlow.*;
import com.intellij.psi.impl.PsiImplUtil;
import com.intellij.psi.impl.source.resolve.graphInference.FunctionalInterfaceParameterizationUtil;
import com.intellij.psi.impl.source.tree.ChildRole;
import com.intellij.psi.impl.source.tree.JavaElementType;
import com.intellij.psi.scope.PsiScopeProcessor;
import com.intellij.psi.tree.IElementType;
import com.intellij.psi.util.PsiTreeUtil;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

public class PsiLambdaExpressionImpl extends ExpressionPsiElement implements PsiLambdaExpression {

  public PsiLambdaExpressionImpl() {
    super(JavaElementType.LAMBDA_EXPRESSION);
  }

  @NotNull
  @Override
  public PsiParameterList getParameterList() {
    return PsiTreeUtil.getRequiredChildOfType(this, PsiParameterList.class);
  }

  @Override
  public int getChildRole(ASTNode child) {
    final IElementType elType = child.getElementType();
    if (elType == JavaTokenType.ARROW) {
      return ChildRole.ARROW;
    } else if (elType == JavaElementType.PARAMETER_LIST) {
      return ChildRole.PARAMETER_LIST;
    } else if (elType == JavaElementType.CODE_BLOCK) {
      return ChildRole.LBRACE;
    } else {
      return ChildRole.EXPRESSION;
    }
  }

  @Override
  public PsiElement getBody() {
    final PsiElement element = getLastChild();
    return element instanceof PsiExpression || element instanceof PsiCodeBlock ? element : null;
  }


  @Nullable
  @Override
  public PsiType getFunctionalInterfaceType() {
    return FunctionalInterfaceParameterizationUtil.getFunctionalType(LambdaUtil.getFunctionalInterfaceType(this, true), this);
  }

  @Override
  public boolean isVoidCompatible() {
    final PsiElement body = getBody();
    if (body != null) {
      try {
        ControlFlow controlFlow = ControlFlowFactory.getInstance(getProject()).getControlFlow(body, LocalsOrMyInstanceFieldsControlFlowPolicy
          .getInstance());
        int startOffset = controlFlow.getStartOffset(body);
        int endOffset = controlFlow.getEndOffset(body);
        return startOffset != -1 && endOffset != -1 && !ControlFlowUtil.canCompleteNormally(controlFlow, startOffset, endOffset);
      }
      catch (AnalysisCanceledException e) {
        return true;
      }
    }
    return true;
  }

  @Override
  public PsiType getType() {
    return new PsiLambdaExpressionType(this);
  }

  @Override
  public void accept(@NotNull final PsiElementVisitor visitor) {
    if (visitor instanceof JavaElementVisitor) {
      ((JavaElementVisitor)visitor).visitLambdaExpression(this);
    }
    else {
      visitor.visitElement(this);
    }
  }

  @Override
  public boolean processDeclarations(@NotNull final PsiScopeProcessor processor,
                                     @NotNull final ResolveState state,
                                     final PsiElement lastParent,
                                     @NotNull final PsiElement place) {
    return PsiImplUtil.processDeclarationsInLambda(this, processor, state, lastParent, place);
  }

  @Override
  public String toString() {
    return "PsiLambdaExpression:" + getText();
  }

  @Override
  public boolean hasFormalParameterTypes() {
    final PsiParameter[] parameters = getParameterList().getParameters();
    for (PsiParameter parameter : parameters) {
      if (parameter.getTypeElement() == null) return false;
    }
    return true;
  }
}