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miguel-vila / keybase.md
Created October 12, 2025 04:03

Keybase proof

I hereby claim:

  • I am miguel-vila on github.
  • I am miguel (https://keybase.io/miguel) on keybase.
  • I have a public key ASDVH-1dpmGPCZPT_1EJkooBVho9_aE34wxXL6bNnceNNQo

To claim this, I am signing this object:

@miguel-vila
miguel-vila / valids.scala
Last active October 16, 2015 18:48
scala> import scalaz.std.list.listInstance
import scalaz.std.list.listInstance
scala> import scalaz.Traverse
import scalaz.Traverse
scala> import scalaz.ValidationNel
import scalaz.ValidationNel
scala> import scalaz.Validation
@miguel-vila
miguel-vila / test-side-effects.hs
Last active September 30, 2015 14:08
module Main where
main = ioA where
ioA = putStrLn "Hola"
ioB = putStrLn "Chao!"
@miguel-vila
miguel-vila / order-monoid.scala
Last active August 29, 2015 14:19
import scalaz._
import Scalaz._
case class Cosa(str: String, f: Float, n: Int)
import scalaz.Order.orderBy
val orderByStr = orderBy { c: Cosa => c.str }
val orderByF = orderBy { c: Cosa => c.f }
val orderByN = orderBy { c: Cosa => c.n }
@miguel-vila
miguel-vila / mutability-in-haskell.hs
Created April 19, 2015 20:55
import Data.IORef
readAndPrint :: IORef Int -> IO ()
readAndPrint ioRef = do
n <- readIORef ioRef
print $ "ioRef = " ++ show n
main = do
ioRef <- newIORef 3
readAndPrint ioRef -- "ioRef 3"
@miguel-vila
miguel-vila / makeFigure.scala
Created January 19, 2015 18:33
def makeFigure(size: Int, spaces: Int, characters: Int, spacesModifier: Int, charactersModifier: Int): String = {
val charsValsStream = Stream.iterate(characters, size)(chars => chars + charactersModifier)
val spacesValsStream = Stream.iterate(spaces, size)(spaces => spaces + spacesModifier)
(charsValsStream zip spacesValsStream).foldLeft(new StringBuilder) { case (builder,(characters,spaces)) =>
builder append (" " * spaces) append ("*" * characters) append "%n".format()
}.toString()
}
@miguel-vila
miguel-vila / ScalaCheck The Definitive Guide.md
Last active November 15, 2016 22:08

ScalaCheck The Definitive Guide

Chapter 1

  • A specification is a definition of a program’s behavior in the general case. Preferably, a specification should not deal with concrete examples of program functionality. Instead it should provide an abstract description of the behavior, that you can use both when implementing the program and when verifying it.

  • Specifications, on the other hand, give us a more complete picture of the program but they are often informal and difficult to verify formally. Instead, tests are used to verify specific cases of a specification.

  • Tests as specification is a concept that is gaining popularity in many test-driven software development processes.

@miguel-vila
miguel-vila / TheoremsForFree.scala
Created September 25, 2014 05:14
def fa[A0,A1](a: A0): A1 = ???
def head[A](l: List[A]): A = l.head
def fmap[A,B](f: A => B)(l: List[A]): List[B] = l.map(f)
"head and then map is the same as map and then head" {
fa[A0,A1] compose head[A0] == head[A1] compose fmap[A0,A1](fa)
}
def tail[A](l: List[A]): List[A] = l.tail
"tail and then map is the same as map and then tail" {
@miguel-vila
miguel-vila / square-roots-functional.scala
Last active October 15, 2015 18:58
// a #:: f(a) #:: f(f(a)) #:: f(f(f(a))) #:: ...
def repeat[A](f: A => A)(a: => A): Stream[A] = a #:: repeat(f)(f(a))
def next(n: Double)(x: Double): Double = (x + n/x)/2.0
def within(eps: Double)(s: Stream[Double]): Double = s match {
case a #:: b #:: rest => if(Math.abs(a-b)<=eps) b else within(eps)(rest)
case _ => throw new Exception("El stream debería tener por lo menos dos elementos")
}
@miguel-vila
miguel-vila / poolvsactorssystem.md
Last active August 29, 2015 14:01