Tuple

Forms that compile (10)

Syntax	Description
(int, int) p = (1, 2);	Declaration by position
(int x, int y) p = (1, 2);	Element names
((int, int), int) p = ((1, 2), 3);	Nested tuples
(int a, int b) = Pair();	Deconstructing a return value
(a, b) = (b, a);	Deconstructing assignment to declared variables
(xs[i], xs[j]) = (xs[j], xs[i]);	Deconstructing assignment to array elements
int Take((int, int) p)	Receiving as a parameter
public (int, int) P;	Holding as a field
(int, int)[] ps = new (int, int)[1];	Array element
a == b	Tuple equality

Forms that don’t compile (2)

Syntax	Description	Error	Reason	Instead
(long, long) b = a;	Assigning one tuple to another	TUKI0099	not yet	Move the elements one at a time (conversions)
(int, int)[][] ps = new (int, int)[2][];	Creating a jagged array of tuples	TUKI0001	not yet	Use a single-level array, or hold a separate array per element
A tuple value is carried as a value, like a struct. It can go anywhere: local variables, arguments, return values, fields, array elements.

Generation

Declaration by position

using UnityEngine;
using Tsukimi;

public class TyTupleDecl : TsukimiBehaviour
{
    void Start()
    {
        (int, int) p = (1, 2);
        Debug.Log(p.Item1);   // => 1
    }
}

Element names

using UnityEngine;
using Tsukimi;

public class TyTupleNamed : TsukimiBehaviour
{
    void Start()
    {
        (int x, int y) p = (1, 2);
        Debug.Log(p.x);   // => 1
    }
}

Nested tuples

using UnityEngine;
using Tsukimi;

public class TyTupleNested : TsukimiBehaviour
{
    void Start()
    {
        ((int, int), int) p = ((1, 2), 3);
        Debug.Log(p.Item2);   // => 3
    }
}

Passing

Deconstructing a return value

using UnityEngine;
using Tsukimi;

public class TyTupleReturn : TsukimiBehaviour
{
    void Start()
    {
        (int a, int b) = Pair();
        Debug.Log(a + b);   // => 3
    }

    private (int, int) Pair() { return (1, 2); }
}

Deconstructing assignment to declared variables

using UnityEngine;
using Tsukimi;

public class TupleAssignExisting : TsukimiBehaviour
{
    void Start()
    {
        int a = 1;
        int b = 2;
        (a, b) = (b, a);
        Debug.Log(a * 10 + b);   // => 21
    }
}

Deconstructing assignment to array elements

The assignment target can also be an array element or a field. The index is evaluated only once.

using UnityEngine;
using Tsukimi;

public class TupleAssignArrayElements : TsukimiBehaviour
{
    void Start()
    {
        int[] xs = new int[2];
        xs[0] = 1;
        xs[1] = 2;
        int i = 0;
        int j = 1;
        (xs[i], xs[j]) = (xs[j], xs[i]);
        Debug.Log(xs[0] * 10 + xs[1]);   // => 21
    }
}

Receiving as a parameter

using UnityEngine;
using Tsukimi;

public class TyTupleParam : TsukimiBehaviour
{
    void Start()
    {
        Debug.Log(Take((1, 2)));   // => 1
    }

    private int Take((int, int) p) { return p.Item1; }
}

Holding as a field

using UnityEngine;
using Tsukimi;

public class TyTupleField : TsukimiBehaviour
{
    void Start()
    {
        P = (1, 2);
        Debug.Log(P.Item1);   // => 1
    }

    public (int, int) P;
}

Array element

It can be an array element. Reading and writing an element is written as ps[0].Item1.

using UnityEngine;
using Tsukimi;

public class TyTupleArray : TsukimiBehaviour
{
    void Start()
    {
        (int, int)[] ps = new (int, int)[1];
        ps[0] = (1, 2);
        Debug.Log(ps[0].Item1);   // => 1
    }
}

Tuple equality

using UnityEngine;
using Tsukimi;

public class ExpressionsTupleEquality : TsukimiBehaviour
{
    void Start()
    {
        (int, int) a = (1, 2);
        (int, int) b = (1, 2);
        Debug.Log(a == b);   // => true
    }
}