upperBound specification

This is the engineering specification for the MotionObservable operator: upperBound.

Overview

upperBound emits either the incoming value or the provided maxValue, whichever is smaller.

Example usage

stream.upperBound(maxValue: 1)

upstream  maxValue  |  downstream
0.50      1         |  0.50
0.75      1         |  0.75
1.00      1         |  1.00
1.25      1         |  1.00
1.50      1         |  1.00

MVP

Expose a upperBound operator API

Use _map to implement the operator. Accept a Comparable type. Emit the result of min(upstreamValue, maxValue).

class MotionObservable<Comparable> {
  public func upperBound(maxValue: Comparable) -> MotionObservable<Comparable>