/*
 * Copyright 2009 The Closure Compiler 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 com.google.javascript.jscomp;

import com.google.javascript.rhino.InputId;
import com.google.javascript.rhino.Node;

/** An interface for accessing the AST root of an input. */
public interface SourceAst {
  /**
   * Gets the root node of the AST for the source file this represents. The AST
   * is lazily instantiated and cached.
   * This node is always non-null, even in the case of parse errors.
   */
  public Node getAstRoot(AbstractCompiler compiler);

  /**
   * Removes any references to root node of the AST.  If it is requested again,
   * another parse will be performed.  This method is needed to allow the ASTs
   * to be garbage collected if the inputs are still around after compilation.
   */
  public void clearAst();

  /** @return The input id associated with this AST */
  public InputId getInputId();

  /** Returns the source file the generated AST represents. */
  public SourceFile getSourceFile();
}
