Reduce Operator

reduce(::Type{R}, reduceFn::Function, seed::R) where R
reduce(reduceFn::F) where { F <: Function }

Creates a reduce operator, which applies a given accumulator reduceFn function over the source Observable, and returns the accumulated result when the source completes, given an optional seed value. If a seed value is specified, then that value will be used as the initial value for the accumulator. If no seed value is specified, the first item of the source is used as the seed.

Arguments

• ::Type{R}: the type of data of transformed value
• reduceFn::Function: transformation function with (data::T, current::R) -> R signature
• seed::R: optional seed accumulation value

Producing

Stream of type <: Subscribable{R}

Examples

using Rocket

source = from([ i for i in 1:10 ])
subscribe!(source |> reduce(Vector{Int}, (d, c) -> [ c..., d ], Int[]), logger())
;

# output

[LogActor] Data: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
[LogActor] Completed

using Rocket

source = from([ i for i in 1:42 ])
subscribe!(source |> reduce(+), logger())
;

# output

[LogActor] Data: 903
[LogActor] Completed

See also: AbstractOperator, RightTypedOperator, ProxyObservable, logger