/source/library/Interlace/Erlang/Tuple.cs

#region Using Directives and Copyright Notice



// Copyright (c) 2007-2010, Computer Consultancy Pty Ltd

// All rights reserved.

// 

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are met:

//     * Redistributions of source code must retain the above copyright

//       notice, this list of conditions and the following disclaimer.

//     * Redistributions in binary form must reproduce the above copyright

//       notice, this list of conditions and the following disclaimer in the

//       documentation and/or other materials provided with the distribution.

//     * Neither the name of the Computer Consultancy Pty Ltd nor the

//       names of its contributors may be used to endorse or promote products

//       derived from this software without specific prior written permission.

// 

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 

// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 

// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 

// ARE DISCLAIMED. IN NO EVENT SHALL COMPUTER CONSULTANCY PTY LTD BE LIABLE 

// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 

// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 

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// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH

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#endregion



// Portions of this code were originally developed for Bit Plantation BitLibrary.

// (Portions Copyright © 2006 Bit Plantation)



using System;

using System.Collections.Generic;

using System.Collections;

using System.Text;

using System.IO;

using System.Net;



namespace Interlace.Erlang

{

    /// <summary>

    /// Represents an Erlang style tuple.

    /// </summary>

    public class Tuple

    {

        object[] _elements;



        /// <summary>

        /// Initializes a new instance of the <see cref="Tuple"/> class.

        /// </summary>

        /// <param name="elements">The elements that make up the tuple items.</param>

        public Tuple(params object[] elements)

        {

            _elements = elements;

        }



        /// <summary>

        /// Gets the object at the specified index.

        /// </summary>

        /// <value>The object.</value>

        public object this[int index]

        {

            get { return _elements[index]; }

        }



        /// <summary>

        /// Gets the number of items in the tuple.

        /// </summary>

        /// <value>The number of items.</value>

        public int Length

        {

            get { return _elements.Length; }

        }



        T InternalAt<T>(int i)

        {

            if (i < 0) throw new IndexOutOfRangeException();



            if (_elements.Length <= i) throw new ErlangProtocolException(string.Format(

                "A tuple of at least {0} (but possibly more) items was expected, and " +

                "a tuple with only {1} elements was received", i + 1, _elements.Length));



            if (typeof(T).Equals(typeof(string)) && _elements[i] is List<object>)

            {

                List<object> list = _elements[i] as List<object>;



                if (list.Count == 0) return (T)(object)"";

            }



            if (!(_elements[i] is T)) throw new ErlangProtocolException(string.Format(

                "The element at index {0} of a tuple is not the correct type."));



            return (T)_elements[i];

        }



        /// <summary>

        /// Gets the tuple at the given index, throwing an <see cref="T:ErlangProtocolException" /> if

        /// the tuple either does not have the specified element or if the element is not the correct type.

        /// </summary>

        /// <param name="i">The index of the element to return.</param>

        /// <returns>The tuple at the specified index.</returns>

        public Tuple TupleAt(int i)

        {

            return InternalAt<Tuple>(i);

        }



        /// <summary>

        /// Gets the string at the given index, throwing an <see cref="T:ErlangProtocolException" /> if

        /// the tuple either does not have the specified element or if the element is not the correct type.

        /// </summary>

        /// <param name="i">The index of the element to return.</param>

        /// <returns>The string at the specified index.</returns>

        public string StringAt(int i)

        {

            return InternalAt<string>(i);

        }



        /// <summary>

        /// Gets the integer at the given index, throwing an <see cref="T:ErlangProtocolException" /> if

        /// the tuple either does not have the specified element or if the element is not the correct type.

        /// </summary>

        /// <param name="i">The index of the element to return.</param>

        /// <returns>The integer at the specified index.</returns>

        public int IntegerAt(int i)

        {

            return InternalAt<int>(i);

        }



        /// <summary>

        /// Gets the atom at the given index, throwing an <see cref="T:ErlangProtocolException" /> if

        /// the tuple either does not have the specified element or if the element is not the correct type.

        /// </summary>

        /// <param name="i">The index of the element to return.</param>

        /// <returns>The atom at the specified index.</returns>

        public Atom AtomAt(int i)

        {

            return InternalAt<Atom>(i);

        }



        /// <summary>

        /// Gets the object at the given index, throwing an <see cref="T:ErlangProtocolException" /> if

        /// the tuple does not have the specified element.

        /// </summary>

        /// <param name="i">The index of the element to return.</param>

        /// <returns>The atom at the specified index.</returns>

        public object ObjectAt(int i)

        {

            return InternalAt<object>(i);

        }



        /// <summary>

        /// Determines whether the specified <see cref="T:System.Object"></see> is equal to the current <see cref="T:System.Object"></see>.

        /// </summary>

        /// <param name="obj">The <see cref="T:System.Object"></see> to compare with the current <see cref="T:System.Object"></see>.</param>

        /// <returns>

        /// true if the specified <see cref="T:System.Object"></see> is equal to the current <see cref="T:System.Object"></see>; otherwise, false.

        /// </returns>

        public override bool Equals(object obj)

        {

            Tuple rhs = obj as Tuple;

            if (rhs == null) return false;



            if (_elements.Length != rhs.Length) return false;



            for (int i = 0; i < _elements.Length; i++)

            {

                if (!Object.Equals(_elements[i], rhs._elements[i])) return false;

            }



            return true;

        }



        /// <summary>

        /// Serves as a hash function for a particular type. <see cref="M:System.Object.GetHashCode"></see> is suitable for use in hashing algorithms and data structures like a hash table.

        /// </summary>

        /// <returns>

        /// A hash code for the current <see cref="T:System.Object"></see>.

        /// </returns>

        public override int GetHashCode()

        {

            int hashCode = 0x00010001 * _elements.Length;



            for (int i = 0; i < _elements.Length; i++)

            {

                if (_elements[i] != null)

                {

                    hashCode ^= _elements[i].GetHashCode();

                }

                else

                {

                    hashCode ^= 0x00020002 * i;

                }

            }



            return hashCode;

        }



        /// <summary>

        /// Returns a <see cref="T:System.String"></see> that represents the current <see cref="T:System.Object"></see>.

        /// </summary>

        /// <returns>

        /// A <see cref="T:System.String"></see> that represents the current <see cref="T:System.Object"></see>.

        /// </returns>

        public override string ToString()

        {

            string[] elementStrings = new string[_elements.Length];



            for (int i = 0; i < _elements.Length; i++)

            {

                elementStrings[i] = _elements[i].ToString();

            }



            return string.Format("Tuple({0})", string.Join(", ", elementStrings));

        }

    }

}