python/src/com/jetbrains/python/psi/impl/ResolveResultList.java

/*
 * Copyright 2000-2013 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.jetbrains.python.psi.impl;

import com.intellij.psi.PsiElement;
import com.intellij.psi.PsiInvalidElementAccessException;
import com.intellij.psi.impl.light.LightElement;
import com.jetbrains.python.psi.resolve.RatedResolveResult;

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

/**
* @author yole
*/
public class ResolveResultList extends ArrayList<RatedResolveResult> {
  public static List<RatedResolveResult> to(PsiElement element) {
    if (element== null) {
      return Collections.emptyList();
    }
    final ResolveResultList list = new ResolveResultList();
    list.poke(element, RatedResolveResult.RATE_NORMAL);
    return list;
  }

  // Allows to add non-null elements and discard nulls in a hassle-free way.

  public boolean poke(final PsiElement what, final int rate) {
    if (what == null) return false;
    if (!(what instanceof LightElement) && !what.isValid()) {
      throw new PsiInvalidElementAccessException(what, "Trying to resolve a reference to an invalid element");
    }
    super.add(new RatedResolveResult(rate, what));
    return true;
  }
}