fold

Full name: taxi.stdlib.fold

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Signature

declare extension function <T,A> fold(collection: T[], initial: A, callback: (T,A) -> A):A

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Description

Iterates over a collection, combining elements with an accumulator to produce a single result.

Unlike reduce, fold starts with an explicit initial value as the accumulator.

// Compute a weighted sum
model Entry {
   weight: Weight inherits Int
   score: Score inherits Int
}
type WeightedTotal by (Entry[]) -> Entry[].fold(0, (Entry, Int) -> Int + (Weight * Score))