rank-by

array →
rank-by(
    ...criteria: expression
) → grouping

Groups array elements by their one-based SQL rank using typed criteria.

Parameters

Name	Type	Required	Description
criteria	expression	Variadic (one or more)	Criteria in the form expression -> :type, optionally followed by direction and null-placement modifiers.

Argument evaluation

Visits each element of the array supplied as pipeline input to this rank-by call.

• criteria: Evaluated once per visited element in declaration order, with that element as context; .field reads its field and $0 reads its first tuple component.

Behavior

Builds a SortTable using the same criterion lowering as sort-by and delegates to rank. Comparer-equal keys share a group. Empty input returns an empty grouping. Invalid coercions become null keys.

Kind: Function
Scope: sorting
Aliases: None