adjacent

array →
adjacent(
    operation: expression
) → array

Evaluates an operation against every consecutive pair of input values. Returns null when the input cannot be evaluated.

Parameters

Name	Type	Required	Description
operation	expression	Yes	Specifies the callable or open expression evaluated against each consecutive pair.

Argument evaluation

Visits consecutive elements of the array supplied as pipeline input to this adjacent call, in source order, starting with the second element.

• operation: Evaluated once per consecutive pair, with T(previous, current) as its input and argument context; $0 resolves to the previous element and $1 to the current element. Empty and singleton arrays do not evaluate the operation.

Behavior

The operation receives T(previous, current). ~f invokes current

f(previous), while f~ invokes previous

f(current); subsequent stages keep that pair as their argument context. Legacy implicit argument injection is deprecated but preserved: a single bare callable still invokes current

f(previous). Use an explicit binding or $1 | f($0); the operator and callable themselves are not deprecated.

Examples

{1, 2, 3} | adjacent(~subtract) → {1, 1}

Kind: Function
Scope: array/sequencing
Aliases: adjacent