Type Alias ButLast<A>

ButLast: A extends readonly []
? readonly []
: A extends readonly [...(infer R), unknown] ? Readonly<R> : Readonly<A>

Gets a new readonly tuple type containing all elements of A except the last one. If A is empty or has only one element, returns readonly []. If A is a general array type, returns Readonly<A>.

Type Parameters

A extends readonly unknown[]
The readonly array or tuple type.

Returns

A new readonly tuple type with the last element removed.

Example

type BL1 = Tuple.ButLast<[1, 2, 3]>; // readonly [1, 2]
type BL2 = Tuple.ButLast<[1]>; // readonly []
type BL3 = Tuple.ButLast<[]>; // readonly []
type BL4 = Tuple.ButLast<readonly number[]>; // readonly number[]

Type Alias ButLast<A>

Type Parameters

Returns

Example

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