001package Torello.Java.Additional; 002 003import java.lang.reflect.Field; 004 005/** 006 * The classes {@code Tuple1} and {@link Tuple0} are here merely for the convenience and the 007 * possibility that an unknown sized tuple might be needed, and on occasion that unknown sized 008 * reference would contain only one (or even zero) elements. 009 * 010 * <BR /><BR />There are otherwise very few uses for a 1 or 0 sized {@code Tuple}. 011 * 012 * <EMBED CLASS=globalDefs DATA-KIND=Tuple DATA-N=1> 013 * <EMBED CLASS='external-html' DATA-FILE-ID=MUTABLE_TUPLE> 014 * @param <A> The type of the <B STYLE='color:red'>only</B> member-field ('{@link #a}'). 015 */ 016public class Tuple1<A> 017 extends TupleN 018 implements java.io.Serializable, Cloneable 019{ 020 /** <EMBED CLASS='external-html' DATA-FILE-ID=SVUID> */ 021 protected static final long serialVersionUID = 1; 022 023 /** This holds a pointer the first and only field / instance. */ 024 public A a; 025 026 /** Constructs this object */ 027 public Tuple1(A a) { this.a = a; } 028 029 /** Constructs this object. Initializes the field to null. */ 030 public Tuple1() { this.a = null; } 031 032 /** 033 * Returns {@code '1'}, indicating how many fields are declared by this class. 034 * @return As an instance of {@code Tuple1}, this method returns {@code '1'}; 035 */ 036 public int n() { return 1; } 037 038 // Super-class uses this for toString, equals, and hashCode 039 // There is an optimization, so if this is requested multiple times, it is saved in a 040 // transient field. 041 042 final Object[] asArrayInternal() 043 { return new Object[] { a }; } 044 045 public Tuple1<A> clone() 046 { return new Tuple1<>(this.a); } 047 048 /** 049 * Returns this {@code Tuple1} instance's only field - field {@link #a}. This method may only 050 * be invoked on an input value of {@code '1'}, or else it throws. A {@code Tuple1} instance 051 * has only a single field that may be retrieved. 052 * 053 * <BR /><BR />This method must be included to properly, fully, implement the ancestor 054 * {@link MultiType} interface. 055 * 056 * @param i This must be passed {@code '1'}, or else this method throws IOOBEX. 057 * 058 * @returns The reference contained by field {@link #a}. If this method returns, its returned 059 * type will always be {@link <A>}. 060 * 061 * @throws IndexOutOfBoundsException As this {@code Tuple1} instance has but a single field, 062 * <I>this exceptions throws for all values of {@code 'i'} - except {@code '1'}</I>. 063 */ 064 public A get(final int i) 065 { 066 if (i != 1) throw new IndexOutOfBoundsException( 067 "This is an instance of Tuple1, and therefore '1' is the only valid value which may " + 068 "be passed to 'i'" 069 ); 070 071 return a; 072 } 073 074 public Ret1<A> toImmutable() 075 { return new Ret1<>(this.a); } 076} 077