lowerBound specification

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

Overview

lowerBound emits either the incoming value or the provided minValue, whichever is larger.

Example usage

stream.lowerBound(minValue: 0)

upstream  minValue  |  downstream
 0.50     0         |  0.50
 0.25     0         |  0.25
 0.00     0         |  0.00
-0.25     0         |  0.00
-0.50     0         |  0.00

MVP

Expose a lowerBound operator API

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

class MotionObservable<Comparable> {
  public func lowerBound(minValue: Comparable) -> MotionObservable<Comparable>