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View gist:5491536
22:06 ~/Projects/Kepler_5923/sandbox (ticket/5923)$ cat Macros.scala
import language.experimental.macros
import scala.reflect.macros.Context
trait Iso[T, U] {
def to(t : T) : U
// def from(u : U) : T
}
object Iso {
@ryanlecompte
ryanlecompte / gist:5537188
Last active Dec 17, 2015
Pimping Iterable to have zipMany/unzipMany operations
View gist:5537188
// Usage examples:
val a = Vector(1,2,3).zipMany(Vector(1,2,3), Vector(5,6,7), Vector(8,9,10), Vector(11,12,13))
Vector(Vector(1, 1, 5, 8, 11), Vector(2, 2, 6, 9, 12), Vector(3, 3, 7, 10, 13))
a.unzipMany
Vector(Vector(1, 2, 3), Vector(1, 2, 3), Vector(5, 6, 7), Vector(8, 9, 10), Vector(11, 12, 13))
// Implementation
import scala.collection._
import scala.collection.generic.CanBuildFrom
@softprops
softprops / JValueWithFilter.scala
Last active Dec 17, 2015
Does away with this pesky compiler warning in scala 2.10.0 "`withFilter' method does not yet exist on org.json4s.JValue, using `filter' method instead"
View JValueWithFilter.scala
import org.json4s.JValue
implicit class LiftJValueWithFilter(self: JValue)
extends JValueWithFilter(self, _ => true)
class JValueWithFilter(self: JValue, p: JValue => Boolean) {
def map(f: JValue => T): List[T] =
self.filter(p).map(f)
def flatMap(f: JValue => List[T]): List[T] =
self.filter(p).flatMap(f)
def foreach(f: JValue => Unit): Unit =
View ::.scala
final case class ::[B](private var hd: B, private[scala] var tl: List[B]) extends List[B]
override def head: B = hd
override def tail: List[B] = tl
override def isEmpty: Boolean = false
private def readObject(in: ObjectInputStream): Unit =
val firstObject = in.readObject()
hd = firstObject.asInstanceOf[B]
assert(hd != ListSerializeEnd)
var current: ::[B] = this
@zraffer
zraffer / CCC.scala
Created Nov 4, 2016
Scala Types are objects of Cartesian Closed Category
View CCC.scala
// Scala Types are objects of Cartesian Closed Category
// (w/o equalities, probably not a category, sorry)
object CCC {
// category structure
def id[T0]: T0=>T0 = x0=>x0
def mul[T1, T2, T3](f23: T2=>T3, f12: T1=>T2): (T1=>T3) = x1 => f23(f12(x1))
// terminal object; adjunction;
type _1_ = Unit
@zraffer
zraffer / package.scala
Last active Apr 26, 2017
a few operations with functors
View package.scala
package object types {
import scala.language.reflectiveCalls
import scala.language.higherKinds
// quantifiers aka (co)ends
type Forall[+F[_]] = { def apply[X]: F[X] }
type Exists[+F[_]] = F[_]
// basic categorical notions
@zraffer
zraffer / CAT.scala
Created Nov 6, 2016
sample of abuse of Java/Scala type system for simulate given formal system
View CAT.scala
package cat
object CAT {
// system traits
sealed trait Type[Self <: Type[Self]]
sealed trait Of[Self <: Of[Self, T], T <: Type[T]]
// types
case class Ob()
View LinVect.scala
object LinVect {
type K = Double
trait NAT[N] { val nat: Int }
def NAT[N: NAT]: NAT[N] = implicitly
def nat[N: NAT]: Int = NAT[N].nat
trait NAT_10
implicit object NAT_10 extends NAT[NAT_10]
@retronym
retronym / config.scala
Last active May 9, 2018
Styles of config propagation: Manual, Implicits, DynamicVariable, Reader
View config.scala
package scalaz.example
object Reader extends App {
/**
* Manual propagation of the environment (in the example, `contextRoot`.)
*/
object Config0 {
def fragment1(contextRoot: String) = <a href={contextRoot + "/foo"}>foo</a>
@tmyymmt
tmyymmt / HexBytesUtil.scala
Created Sep 15, 2012
hex2bytes and bytes2hex fixed
View HexBytesUtil.scala
object HexBytesUtil {
def hex2bytes(hex: String): Array[Byte] = {
hex.replaceAll("[^0-9A-Fa-f]", "").sliding(2, 2).toArray.map(Integer.parseInt(_, 16).toByte)
}
def bytes2hex(bytes: Array[Byte], sep: Option[String] = None): String = {
sep match {
case None => bytes.map("%02x".format(_)).mkString
case _ => bytes.map("%02x".format(_)).mkString(sep.get)