squito’s gists

squito / basicprofiling.scala

Last active December 18, 2015 17:39

	val n = 1e7.toInt
	val (rawArray, rawBB, rawFloatBuf) = initArrays(n)
	println("result = " + th.pbench({
	var idx = 0
	var sum = 0f
	while(idx < n) {
	sum += rawArray(idx)
	idx += 1
	}
	sum

squito / arraylikeProfile.scala

Last active December 18, 2015 17:39

	trait ArrayLike[@specialized T] {
	def apply(idx: Int) : T
	def update(idx: Int, value: T)
	def length: Int
	def size: Int = length
	}

	def sumArrayLike(arr: ArrayLike[Float]): Float = {
	var idx = 0
	var sum = 0f

squito / typeclassProfile.scala

Last active December 18, 2015 17:39

	trait ArraySummer[-T] {
	def sum(t: T): Float
	}

	/** one TypeClass per concrete implementation */
	object SpecificSummers {
	implicit object SimpleWrappedFloatArraySummer extends ArraySummer[SimpleWrappedFloatArray] {
	def sum(arr: SimpleWrappedFloatArray): Float = {
	...
	}

squito / gist:5921876

Created July 3, 2013 19:20

type variance & toMap

	scala> trait A
	defined trait A

	scala>

	scala> class B extends A
	defined class B

	scala> class C extends A
	defined class C

squito / macro compiler error.scala

Last active August 23, 2017 05:45

The horrors of compiler errors when working with macros ...

	scala> def classExpandMacroImpl(c: Context)(s: c.Expr[Any]) : c.Expr[Any] = {
	\| import c.universe._
	\|
	\| val cdef = s.tree match {
	\| case Block(List(x:ClassDef), _) => x
	\| case _ => c.abort(c.enclosingPosition, "Was expecting a block w/ a ClassDef")
	\| }
	\|
	\| val q"class $name { ..$body }" = cdef
	\| val newdefs = List[c.universe.Tree](q"def x: Int = z + 7", q"def y: Float = z + 3.2f")

squito / addedTrait.scala

Last active January 28, 2016 07:41

code samples to go along w/ a blog post on macros imranrashid.com/posts/learning-scala-macros/

	val addedTrait = Select(Select(Select(
	Select(Ident(newTermName("com")), newTermName("imranrashid")),
	newTermName("oleander")),newTermName("macros")),
	newTypeName("SimpleTrait"))

squito / badValDefMacro.scala

Last active August 12, 2020 20:57

some basic macros with quasiquotes. Accompanies this blog post <http://imranrashid.com/posts/learning-scala-macros/>. Partially a translation of this example <http://www.warski.org/blog/2012/12/starting-with-scala-macros-a-short-tutorial/> to quasiquotes.

	def getValMacro(c: Context)(s: c.Expr[Any]) : c.Expr[Any] = {
	import c.universe._
	val q"val $name = $value" = s.tree
	c.Expr(value)
	}

	def getVal(s: Any) = macro getValMacro

	getVal{val x = 17}
	error: exception during macro expansion:

squito / findFirst.scala

Last active December 28, 2015 20:18

find first match in scala nested for loops

	val data = (1 to 10).toSeq.map{i => (0 to i).map{_.toString}.toSeq}

	val iters = for {
	sub <- data.iterator
	d <- sub.iterator
	} yield d

	val r = iters.find{x =>
	println(s"checking $x")
	x == "6"

squito / KafkaSimpleConsumerUtils.scala

Created November 20, 2013 15:14

Some scala utils for working w/ kafka SimpleConsumer. realized there was a way for me to use the ConsumerGroup API instead, so putting this here just in case its useful to me later on ...

	import kafka.consumer.SimpleConsumer
	import kafka.common.TopicAndPartition
	import kafka.api._
	import scala.annotation.tailrec
	import scala.util._

	object KafkaSimpleConsumerUtils {

	def getLastOffset(consumer: SimpleConsumer, topic: String, partition: Int, whichTime: Long, clientName: String): Try[Long] = {
	val tap = new TopicAndPartition(topic, partition)

squito / implicits.scala

Last active December 29, 2015 00:39

useful scala implicits. Since IDEs dont' have nice tools for auto-completing implicit imports, this is a handy reference

	// for 20.seconds, etc.
	import scala.concurrent.duration._
	// this is twitters version, only use if you need it to work w/ another API, otherwise prefer the scala version
	import com.twitter.conversions.time._

	//for 6.megabytes.bytes
	import com.twitter.conversions.storage._

	//===QF implicits===

Imran Rashid squito