Px

sealed abstract class Px[A]

A mechanism for caching data with dependencies.

This is basically a performance-focused, lightweight implementation of pull-based <a href="http://en.wikipedia.org/wiki/Functional_reactive_programming">FRP</a>, pull-based meaning that in the chain A→B→C, an update to A doesn't affect C until the value of C is requested.

What does Px mean? I don't know, I just needed a name and I liked the way @lihaoyi's Rx type name looked in code. You can consider this "Performance eXtension". If this were Java it'd be named AutoRefreshOnRequestDependentCachedVariable.

Companion: object

class Object

trait Matchable

class Any

class Root[A]

class Var[A]

class ThunkM[A]

class Derivative[A]

class DerivativeBase[A, B, C]

class Map[A, B]

class FlatMap[A, B]

Value members

Abstract methods

Get the last used value without updating.

Revision of its value. Increments when value changes.

Get the latest value, updating itself if necessary.

Concrete methods

If this Px contains a function, it can be extracted and the Px dropped from the signature. Every time the function is invoked it will use the latest value of this Px, even if you don't explicitly hold a reference to it anymore.

Example. From a Px[Int => String], an Int => String can be extracted.