leanprops-core

leanprops-core is core of LeanProps.

It provides some important classes and traits: Tiers[A], Listable[A] and Inspectable[A].

Installation

Stable

Unfortunately LeanProps has no stable version...

HEAD

Add this line into your build.sbt:

lazy val leanpropsCoreRef = ProjectRef(uri("git://github.com/MakeNowJust/leanprops.git"), "core")

Then, add .dependsOn(...) into your project definition:

lazy val root = (project in file("."))
  .dependsOn(leanpropsCoreRef)
  // ...

Usage

All examples need to import codes.quine.leanprops of course:

import leanprops._

When you have a property p that is a function returns Boolean value, then holds(100)(p) tests p against first 100 possible arguments.

val p: Int => Boolean = { x => x == x }
// p: Int => Boolean = <function1>
holds(100)(p)
// res0: Boolean = true

// Or, passes a property to `holds` as function literal.
holds(100) { (x: Int) => x == x }
// res1: Boolean = true

counterExample(100)(p) finds arguments that not satisify p. Such arguments are called as a counter example. When a counter example is found, it returns Some(...) with inspect-ed arguments, otherwise it returns None.

counterExample(100) { (x: Int) => x != x }
// res2: Option[Seq[Seq[String]]] = Some(List(List("0")))

counterExample(100) { (x: Int) => x == x }
// res3: Option[Seq[Seq[String]]] = None