harrah

trait ~>[A[_], B[_]] { def apply[T](a: A[T]): B[T] }

object Test {
  def x[A[_],B[_]](f: A ~> B) = f

  import Param._
  val f = x { (p: Param[Option,List]) => p.ret( p.in.toList ) }

  val a: List[Int] = f( Some(3) )
  val b: List[String] = f( Some("aa") )

harrah

Proposal: Default compiler/interpreter classpath in a managed environment

The compiler uses a default classpath of 'java.class.path'.  Because many
applications do not use custom class loaders, this default is often sufficient
and no classpath configuration is required.  This is because all jars- the
application and its dependencies, including the Scala compiler and library- are
in 'java.class.path' and the class loader for the application is the same as
that for Scala.

However, it does not work in more complicated setups, including various managed

harrah

import scala.xml._
import transform._

object Test {
	// utility method for a simple interface to the transform package
	def transform(xml: Node)(f: Node => Seq[Node]) = {
		val rule = new RewriteRule { override def transform(n: Node) = f(n) }
		val transformer = new RuleTransformer(rule)
		transformer transform xml
	}

harrah

// in comments, the syntax:
//   [A](B => C)
// represents a quantified function literal parameterized by type A

object Z
{
	// The main type, a quantified function object
	trait Q[M[_], N[_]] { def apply[C](m: M[C]): N[C] }
	
		// Helper Types

harrah

import sbt._

class PrivateConfigurations(info: ProjectInfo) extends DefaultProject(info)
{
	// define a custom configuration that will not get published
	val compileOnly = config("compileOnly") hide

	// add all dependencies in that configuration to the compile classpath
	override def compileClasspath = super.compileClasspath +++ managedClasspath(compileOnly)

harrah

# only keep nodes in scala.collection and immediate parents that aren't scala.ScalaObject, java.lang.Object, or scala.Product
gvpr 'E[index(tail.label, "scala.collection.") > -1 && index(head.label, "scala.ScalaObject") == -1
   && index(head.label, "java.lang.Object") == -1 && index(head.label, "scala.Product") == -1] {}' library_inherit.dot |
# discard nodes without edges
gvpr 'N[degree > 0] {} E{}'  |
# make classes blue and objects red and shorten some names
sed -e 's/label="class /color=blue label="/' \
 -e  's/label="object /color=red label="/' \
 -e 's/label="scala.collection./label="c./' \
 -e 's/label="c.immutable./label="c.immut./' \