lildata’s gists

lildata / JDBCResultSettoStream.scala

Last active August 29, 2015 14:18

	new Iterator[String] {
	def hasNext = resultSet.next()
	def next() = resultSet.getString(1)
	}.toStream

lildata / gist:0c5862930c5b59446067

Last active April 13, 2016 01:15 — forked from aldonline/gist:6959105


	object x {

	// stream a sql query
	def sql( str:String ):Stream[ResultSet] = withStatement { s =>
	val rs = s executeQuery str
	new Iterator[ResultSet] { def hasNext = rs.next ; def next = rs }.toStream
	}

	// loan a sql statement

lildata / ReadFile.scala

Created May 18, 2015 19:08

Read a file, no ceremony :-D

println(scala.io.Source.fromFile("some.txt").mkString)

lildata / doXtimesImplicit.scala

Created May 19, 2015 20:12

how to create a X times syntax with implicits, also cool for DSLs

	implicit def intWithTimes(n: Int) = new {
	def times(f: => Unit) = 1 to n foreach {_ => f}
	}

	5 times {
	println("Hello World")
	}

lildata / companionOf.scala

Last active August 29, 2015 14:21 — forked from piotrga/gist:5928581

Get companion object instance with new Scala reflection API

	trait ReflectionSugars{
	import scala.reflect.runtime.{universe => ru}
	private lazy val universeMirror = ru.runtimeMirror(getClass.getClassLoader)

	def companionOf[T](implicit tt: ru.TypeTag[T]) = {
	val companionMirror = universeMirror.reflectModule(ru.typeOf[T].typeSymbol.companionSymbol.asModule)
	companionMirror.instance
	}

	}

lildata / scalaColoredREPL.sh

Created May 24, 2015 18:42

Enable coloring in the Scala REPL

$ scala -Dscala.color

lildata / SparkDataFrameTest.scala

Last active August 29, 2015 14:21

Playing with Spark Dataframe, see https://spark.apache.org/docs/latest/api/scala/#org.apache.spark.sql.DataFrame

	scala> val sqlc = new org.apache.spark.sql.SQLContext(sc)
	scala> import sqlc.implicits._ //to implicitly convert an RDD to a DataFrame
	scala> val df1 = sqlc.load("/home/....json","json")
	scala> df1.printSchema
	scala> df1.select("name").show
	scala> df1.select("name", df1("age") + 1).show
	scala> df1.filter(df1("age") > 10).show
	scala> df1.groupBy("age").count().show

lildata / unless.scala

Created June 4, 2015 17:51

Funny, defining an "unless" construct

	def unless(expr: Boolean)(perform: ()=>Unit) { if(!expr) perform() }

	unless(6 == 5) { ()=>println("Hello world") }

lildata / prepostfix.scala

Created June 4, 2015 18:24

Prefix (unary_) & Postfix are cool for DSLs

	case object CONNECTION {
	def unary_! = DISCONNECTION
	def REMOVE = DISCONNECTION
	}

	case object DISCONNECTION

	println(!CONNECTION == DISCONNECTION) //true
	println((CONNECTION REMOVE) == DISCONNECTION) //true

lildata / seesaw-repl-tutorial.clj

Last active August 29, 2015 14:23 — forked from daveray/seesaw-repl-tutorial.clj

	; A REPL-based, annotated Seesaw tutorial
	; Please visit https://github.com/daveray/seesaw for more info
	;
	; This is a very basic intro to Seesaw, a Clojure UI toolkit. It covers
	; Seesaw's basic features and philosophy, but only scratches the surface
	; of what's available. It only assumes knowledge of Clojure. No Swing or
	; Java experience is needed.
	;
	; This material was first presented in a talk at @CraftsmanGuild in
	; Ann Arbor, MI.

Programming is fun lildata