timjb

Hello, my name ist {{name}} and I am {{age}} years old.

puffnfresh

module DefaultSuperclass

data Identity' i = Id' i

class Functor' (f : Type -> Type) where
  map' : (a -> b) -> f a -> f b

class Functor' f => Applicative' (f : Type -> Type) where
  instance Functor' f where
    map' = ap' . pure'

meh

Kernel keywords

• apply/2
• apply/3
• cond/1
• destructure/2
• exit/1
• if/2
• in/2
• match?/2

bitemyapp

The Learning Haskell guide has been moved to a git repo to enable outside contribution

Find it here: https://github.com/bitemyapp/learnhaskell

tpolecat

Hi, looking for scalac flags?

This gist has been upgraded to a blog post here.

chaitanyagupta

Reader Macros in Common Lisp

This post also appears on lisper.in.

Reader macros are perhaps not as famous as ordinary macros. While macros are a great way to create your own DSL, reader macros provide even greater flexibility by allowing you to create entirely new syntax on top of Lisp.

Paul Graham explains them very well in [On Lisp][] (Chapter 17, Read-Macros):

The three big moments in a Lisp expression's life are read-time, compile-time, and runtime. Functions are in control at runtime. Macros give us a chance to perform transformations on programs at compile-time. ...read-macros... do their work at read-time.

jnthn

sub trait_mod:<is>(&c, :$curried!) {
    my $arity = &c.arity;
    &c.wrap(-> |args {
        args.list.elems == $arity
            ?? callsame()
            !! &c.assuming(|args)
    });
}

sub foo($a, $b) is curried {

runarorama

import scalaz._

// A right Kan extension of `F` along itself, constrained by `C`.
trait RCodensity[C[_], F[_], A] {
  def apply[R:C](k: A => F[R]): F[R]
}

object RCodensity {
  implicit def codensityMonad[C[_], F[_]]: Monad[({type f[x] = RCodensity[C,F,x]})#f] =
      new Monad[({type f[x] = RCodensity[C,F,x]})#f] {

puffnfresh

module LoobVerifiedMonoid

data Loob = Eurt | Eslaf

instance Semigroup Loob where
  Eurt <+> _ = Eurt
  Eslaf <+> r = r

instance Monoid Loob where
  neutral = Eslaf

moritz

use v6;

sub t ($x, $y, :$label = 'sum') {
    say "$label: ", $x + $y;
}

sub namecall(&c, *@pos, *%named is rw) {
    my %name-to-idx;
    for &c.signature.params.kv -> $idx, $p {
        next if $p.named;