HApplyTest.scala

import HList._

object HApplyTest 
{
	// heterogeneous map ...
	//   We construct an HList of data and an HList of functions and apply the functions to the data cell-by-cell.

		// data HLists
	val y1 = 9.75 :: 'x' :: HNil
	val y2 = -2.125 :: 'X' :: HNil
		// the functions to apply
	val z = ((_: Double) + .5) :: ( (_: Char).isUpper) :: HNil
	// apply, check result values and types
	val z1 = happly(z)(y1)
		// check types
	val z1Types : Double :: Boolean :: HNil = z1
		// check values
	val 10.25 :: false :: HNil = z1

	val z2 = happly(z)(y2)
		// check types
	val z2Types : Double :: Boolean :: HNil = z2
		// check values
	val -1.625 :: true :: HNil = z2

		// more complicated example, with nested HLists
	val xx = List(3, 4, 5) :: (3 :: 'w' :: HNil) :: HNil
		// function to apply to the List element
	val zsub1 = (_: List[Int]).flatMap("s" * _)
		// heterogeneous function to apply to the HList element.
		//   Note the call to `part` for partial application since it isn't actually a function
	val zsub2 = partial( ( (_: Int) * 13) :: ( (_: Char).isLetter ) :: HNil )
		// combine the two functions into one HList
	val f = zsub1 :: zsub2 :: HNil
		// do the heterogeneous map- note that no types need to be explicitly provided.
	val r = happly(f)(xx)

		// types
	val rTypes : List[Char] :: ( Int :: Boolean :: HNil ) :: HNil = r
		// values
	val ExpectedHead = List.fill(xx.head.sum)('s')
	val ExpectedHead :: (39 :: true :: HNil) :: HNil = r

	def run()
	{
		println(z1)
		println(z2)
		println(r)
	}
}