retronym

indylambda: Putting invokedynamic to work for Scala

Java 8 introduced lambdas to the Java language. While the design choices differ in many regards from Scala's functions, the underlying mechanics used to represent Java lambdas is flexible enough to be used as a target for the Scala compiler.

Lambdas in Java

Java does not have canonical heirarchy of generic function types (ala scala.FunctionN), but instead allows a lambda to be used as a shorthand for an anonymous implementation of an Functional Interface

Here's an example of creating a predicate that closes over one value:

tinkerware

# You will need Mercurial; get it with `brew install hg`.

hg clone http://hg.openjdk.java.net/jdk8u/jdk8u
cd jdk8u
hg update jdk8u92-b14
chmod +x ./get_source.sh; ./get_source.sh
cd hotspot/src/share/tools/hsdis
wget http://ftp.heanet.ie/mirrors/gnu/binutils/binutils-2.26.tar.gz
tar -xzf binutils-2.26.tar.gz
make BINUTILS=binutils-2.26 ARCH=amd64

retronym

Tuning Scala[c]

Using every tool in the box to squeeze out some more compiler performance.

Tooling

Java Flight Recorder

JMC / JFR resources:

• http://docs.oracle.com/javacomponents/jmc-5-5/jfr-runtime-guide/about.htm

mushtaq

// [info] Running p.Run
// List(Fish(Bob, Esq.,12), Kitty(Thor, Esq.,java.awt.Color[r=255,g=200,b=0]))

package misc

import java.awt.Color

trait Pet[A] {
  def name(a: A): String
  def renamed(a: A, newName: String): A

retronym

Process

• Scala PR review checklist
• Scala SIP Template / review checklist

Ideas

• Finalize classes/methods in stdlib
• Unused code detection / eradication
• optimize local lazy vals that don't escape

gseitz

package sbtcomplete

import sbt._
import complete.JLineCompletion
import Keys._

object SbtComplete {

  private val CompletionsCommand = "completions"
  private val CompletionsBrief = ("<arg>", "The string to complete.")