Tuple[*Ts]

Tuples are immutable, ordered sequences of values. They are produced by certain operations such as iterating over key-value pairs. The Tuple type object is in the prelude, so Tuple(iterable) is available without an explicit import.

Inherits from: Iterable[Union[...Ts]]

Implements: Spread[Ts], Unpack[Ts, Rest: BaseSeq[Ts], Pos: Tuple[...Ts]], Index[Ts], Seq[Union[...Ts]]

Constructor

Tuple[T] iterable

Builds a tuple from an iterable.

The lowercase tuple factory instead collects its positional arguments verbatim.

Parameters

Name	Type	Description
self	Tuple[...T]	Receiver.
iterable	Iterable[T]	values to collect

Example

let tup = Tuple([1, 2, 3])
assert_eq $tup[1] 2

for k v = {name: "Alice", age: 30}
  # each pair is a tuple
  echo "$k: $v"

Fields

len @ Int ^[get]

Returns the number of elements.

Methods

(index)[K] key -> IndexItem[Ts, K] ^{overload 1 of 2}

Returns an element, or a new tuple for a slice.

let pair = {name: "Alice"}.pairs().next()
assert_eq $pair[0] :name:
assert_eq $pair[1] "Alice"
assert_eq $pair[-1] "Alice"

Tuples are immutable; indexed assignment is not supported.

let tup = Tuple [0, 1, 2, 3]
assert_eq $tup[1..3] (tuple 1 2)
assert_eq $tup[..2] (tuple 0 1)
assert_eq $tup[2..] (tuple 2 3)
assert_eq $tup[..] (tuple 0 1 2 3)
assert_eq $tup[Range 0 4 2] (tuple 0 2)
assert_eq $tup[Range nil nil -1] (tuple 3 2 1 0)

Omitted start means 0, omitted end means the tuple length, and negative endpoints count from the end. Negative steps reverse the slice.

Parameters

Name	Type	Description
key	K

(index) range -> Tuple[...Union[...Ts]] ^{overload 2 of 2}

Returns an element, or a new tuple for a slice.

let pair = {name: "Alice"}.pairs().next()
assert_eq $pair[0] :name:
assert_eq $pair[1] "Alice"
assert_eq $pair[-1] "Alice"

Tuples are immutable; indexed assignment is not supported.

let tup = Tuple [0, 1, 2, 3]
assert_eq $tup[1..3] (tuple 1 2)
assert_eq $tup[..2] (tuple 0 1)
assert_eq $tup[2..] (tuple 2 3)
assert_eq $tup[..] (tuple 0 1 2 3)
assert_eq $tup[Range 0 4 2] (tuple 0 2)
assert_eq $tup[Range nil nil -1] (tuple 3 2 1 0)

Omitted start means 0, omitted end means the tuple length, and negative endpoints count from the end. Negative steps reverse the slice.

Parameters

Name	Type	Description
range	Range[Int]

(iter)() -> UnpackIter[Union[...Ts]]

Returns an iterator with read-only unpacking.

(spread)() -> Spread[Ts]

Spreads the items.

(unpack)() -> Tuple[...Ts]

Unpacks tuple elements.

for k v = {name: "Alice", age: 30}
  echo "$k = $v"

contains element -> Bool

Tests whether the tuple contains the given element (by equality).

Parameters

Name	Type	Description
element	Value	the value to check

copy() -> Tuple[...Ts]

Returns a shallow copy of the tuple. Because tuples are immutable, the returned copy may be the same object.

get[D = nil] index … -> (Union[...Ts] | D)

Retrieves the value at the given index. Returns nil if out of bounds and no alternative is provided. Negative indexes count from the end.

Parameters

Name	Type	Description
index	Int	the index to access
:default?	D
:else?	(() -> D)

iter() -> UnpackIter[Union[...Ts]]

Returns an iterator with read-only unpacking.

pairs() -> UnpackIter[Tuple[Int, Value]]

Returns an iterator yielding (index, value) pairs.