Comparison.scala

sealed trait Comparison {
	type gt <: Bool
	type ge <: Bool
	type eq <: Bool
	type le <: Bool
	type lt <: Bool
	type Match[IfLT <: Up, IfEQ <: Up, IfGT <: Up, Up] <: Up
}
sealed trait GT extends Comparison {
	type Match[IfLT <: Up, IfEQ <: Up, IfGT <: Up, Up] = IfGT
	type eq = False
	type gt = True
	type lt = False
	type le = False
	type ge = True
}
sealed trait LT extends Comparison {
	type Match[IfLT <: Up, IfEQ <: Up, IfGT <: Up, Up] = IfLT
	type eq = False
	type gt = False
	type lt = True
	type le = True
	type ge = False
}
sealed trait EQ extends Comparison {
	type Match[IfLT <: Up, IfEQ <: Up, IfGT <: Up, Up] = IfEQ
	type eq = True
	type gt = False
	type lt = False
	type le = True
	type ge = True
}
object Comparison {
	def show[C <: Comparison](implicit rep: ComparisonRep[C]): String = rep.value
	implicit def eqToRep: ComparisonRep[EQ] = new ComparisonRep[EQ]("eq")
	implicit def ltToRep: ComparisonRep[LT] = new ComparisonRep[LT]("lt")
	implicit def gtToRep: ComparisonRep[GT] = new ComparisonRep[GT]("gt")
	final class ComparisonRep[+C <: Comparison](val value: String)
}