content: /* 
   * Kodkod -- Copyright (c) 2005-present, Emina Torlak
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  package kodkod.ast;
  
  import java.util.Arrays;
  import java.util.Iterator;
  
  import kodkod.ast.visitor.ReturnVisitor;
  import kodkod.ast.visitor.VoidVisitor;
  import kodkod.util.collections.Containers;
  
  
  /** 
   * A sequence of decls. 
   * 
   * @specfield size: int
   * @specfield decls: [0..size) -> one Decl
   * @invariant size > 0
   * @invariant children = decls
   * @author Emina Torlak 
   */
  public class Decls extends Node implements Iterable<Decl> {
  	private final Decl[] decls;
  	
  	/**
  	 * Constructs a Decls object with itself as its sole
  	 * declaration.  This constructor can only be called
  	 * from inside the Decl constructor; otherwise it will
  	 * throw a ClassCastException.
  	 * @ensures this.declarations' = 0->this
  	 * @throws ClassCastException  this !in Decl
  	 */
      Decls() {
      	this.decls = new Decl[]{ (Decl) this };
      }
      
      /**
  	 * Constructs a new Decls with the specified head and tail.
  	 * @requires head.size > 0 && tail.size > 0
  	 * @ensures this.size' = head.size + tail.size &&
  	 *          (all i: [0..head.size) | this.decls[i] = head.decls[i]) &&
  	 *          (all i: [head.size..this.size') | this.decls[i] = tail.decls[i])
  	 * @throws NullPointerException  head = null || tail is null 
  	 */
  	private Decls(Decls head, Decls tail) {
  		this.decls = new Decl[head.size()+tail.size()];
  		System.arraycopy(head.decls, 0, decls, 0, head.size());
  		System.arraycopy(tail.decls, 0, decls, head.size(), tail.size());
  	}
      
      /**
       * Returns the number of decls in this Decls object.
       * @return this.size
       */
      public int size() { return decls.length; }
      
      /**
       * Returns the ith declaration in this Decls sequence.
       * @requires 0 <= i < this.size
       * @return this.decls[i]
       */
      public Decl get(int i) { return decls[i]; }
      
      /**
       * Returns an unmodifiable iterator over the decls in this Decls object.
       * @return an unmodifiable iterator over the decls in this Decls object.
       */
      public Iterator<Decl> iterator() { return Containers.iterate(decls); }
      
      /**
       * Returns a sequence of this.size + other.size decls that has 
       * these decls as the prefix and the given decls as the suffix.
       * @return {ds: Decls | ds.size = this.size + other.size && 
       *                      ds.decls = this.decls + 
       *                      {i: [this.size..this.size+other.size), d: Decl | d = other.decls[i-this.size] }
       * @throws NullPointerException  decl = null
       */
      public final Decls and(Decls other) {
      	return new Decls(this, other);
      }
      
      /**
       * {@inheritDoc}
       * @see kodkod.ast.Node#accept(kodkod.ast.visitor.ReturnVisitor)
       */
      public <E, F, D, I> D accept(ReturnVisitor<E, F, D, I> visitor) {
          return visitor.visit(this);
      }
     
      /**
       * {@inheritDoc}
       * @see kodkod.ast.Node#accept(kodkod.ast.visitor.VoidVisitor)
       */
      public void accept(VoidVisitor visitor) {
          visitor.visit(this);
      }
      
      /**
       * {@inheritDoc}
       * @see kodkod.ast.Node#toString()
       */
      public String toString() {
          return Arrays.toString(decls);
      }
      
  }
  