Skip to content

Instantly share code, notes, and snippets.

package skiequivalence
sealed trait SKIExpression {
def convert:SKIExpression
def freeVariables:Set[TermVariable]
}
case class TermVariable(variable:String) extends SKIExpression {
override def convert = this
override def freeVariables = Set(this)
trait Functor[T, F[_]] { self: F[T] =>
def map[K](fn: T => K): F[K]
}
sealed trait Optional[+T] extends Functor[T, Optional]
case class Maybe[T](value:T) extends Optional[T] {
override def map[K](fn: T => K) = Maybe(fn(value))
}
case object Nope extends Optional[Nothing] {
import Data.List
import Data.Char
data Prop = Const Bool
|Var Char
|Not Prop
|And Prop Prop
|Implies Prop Prop
deriving Show