Uncategorized

ScalaCollider – saving presets with json

Sometimes it is useful to save presets when working with ScalaCollider. In Supercollider this is usually done with

writeArchive

and

readArchive

, which can be called on any object that does not contain open functions. After review several possibilities to do the same in scala, I found that the easiest is to use lift-json for JSON parsing and generation. JSON is a human readable format, which is quite convenient.

The easiest way to save a preset would be using case classes to hold the data, since lift-json can automatically serialize and deserialize them:

import java.io.{FileWriter}
import net.liftweb.json._
import net.liftweb.json.Serialization.{write,read}
import scala.io.Source._

object TestJsonSerialization {

  def main(args: Array[String]) {
    implicit val formats = DefaultFormats

    case class Person(name: String, address: Option[String], num:List[Int])
    case class Container(persons:List[Person])
    val people = Container(List(Person("joe", None, List(1,2,3,4)),
        Person("jack", Some("NY grand central"), List(5,6,7,8))))

    //write values to disk
    val fw = new FileWriter("test.txt")
    fw.write(write(people))
    fw.close()

    //get values back
    val jsonString = fromFile("test.txt").mkString
    println(pretty(render(parse(jsonString))))
    println(read[Container](jsonString))
  }

}

To compile the example with sbt use this project file:

import sbt._

class JSONProj(info: ProjectInfo) extends DefaultProject(info)
{
  val json = "net.liftweb" %% "lift-json" % "2.3"
}

Tags | JSON, Presets, scala, ScalaCollider

Scala pattern matching and variables

Today I was debugging some scala code for more than one hour. Turns out that if you use a variable in the pattern you are matching you need to put it in back ticks:

val thing = 3
4 match {
    case thing => println("bingo")
}

This code will match because thing will just became a new variable that is a container for whatever values are being matched.

val thing = 3
4 match {
    case `thing` => println("bingo")
    case _ => println("no match")
}

This code on the other hand will not match, because the variable thing is used, whose content is 3.

Tags | pattern matching, scala

Bwana – Graphical man pages in osx

I’ve been using Bwana to show me man pages in safari. Reading man pages in terminal is just ridiculous in 2011…

I use a little script to open the manpage from terminal:

open man:$1

I have saved it to

/usr/local/bin/mman

so I only have to do

mman ln

to get the man page for ln.

DiffMerge

git config --global diff.tool diffmerge
git config --global difftool.diffmerge.cmd "diffmerge "$LOCAL" "$REMOTE""

git config --global merge.tool diffmerge
git config --global mergetool.diffmerge.cmd "diffmerge --merge --result="$MERGED"
  "$LOCAL" "$BASE" "$REMOTE""
git config --global mergetool.diffmerge.trustexitcode false

git mergetool -t diffmerge

git difftool -t diffmerge master~1 myfile.sc