keigoi

(* Monads with camlspotter's ppx_typeclass *)
(* see ppx_typeclass http://bitbucket.org/camlspotter/ppx_typeclass/ *)

(* Set-up higher-kinded polymorphism, see https://ocamllabs.github.io/higher/lightweight-higher-kinded-polymorphism.pdf *)
type ('p, 'f) app = .. (* Type-level defunctionalization *)

module Newtype1 (T: sig type 'a t end) () = struct
  type 'a s = 'a T.t
  type t
  type (_, _) app += App : 'a s -> ('a, t) app

keigoi

(* try at http://try.ocamlpro.com/js_of_ocaml/ *)
open Graphics
let () = open_graph " 900x600"
let rec k c =
  clear_graph ();
  moveto 450 300;
  draw_string (string_of_int c);
  ignore (Dom_html.window##setTimeout(Js.wrap_callback (fun _ -> k (c+1)), 0.1))
let () = k 0 ;;

keigoi

    function xpath(elm, expr) {                                                                                                                                                                                                            
        var it = document.evaluate(expr, elm, null, XPathResult.ANY_TYPE, null);                                                                                                                                                           
        var typ = it.resultType;                                                                                                                                                                                                           
        switch(typ) {                                                                                                                                                                                                                      
        case XPathResult.NUMBER_TYPE:                                           

keigoi

let rec fib n =
  if n <= 1 then
    1
  else
    let x = fib (n-1)
    and y = fib (n-2)
    in x+y

let main n = print_int (fib n)
                     

keigoi

SMLYACC=smlyacc
SMLLEX=smllex
SMLSHARP=smlsharp

OBJS=calc.grm.o calc.lex.o calc.o
SMI=calc.grm.smi calc.lex.smi calc.smi


all: calc

keigoi

// check this with facebook infer 0.9.4
public class Hello {
  public static void main(String[] args) {
      Object o1 = new Object();
      Object o2 = new Object();
      Object n = null;
      Object[] arr = {o1, o1, o1, o1, o1};
      for(int i=0; i<arr.length; i++) {
          if(arr[i].equals(o2)) {
              n.equals(n); // never reached but reported as an error

keigoi

# A monad in Crystal
class Id(T)
  getter :value
  
  def initialize(@value : T)
  end

  def bind(&x : T -> Id(U)) forall U
    yield @value
  end

keigoi

class IxMonad<X,Y,T>(val x:T) {}

class Cons<HD,TL>(val hd : HD, val tl : TL) {}
class Nil();

fun <X,Y,T> ret(x: T) : IxMonad<X,Y,T> {
    return IxMonad<X,Y,T>(x)
}

fun <T> run(m : IxMonad<Nil,Nil,T>) : T {

keigoi

import java.util.function.Consumer;
import java.util.ArrayList;

public class TypeError {


    public static <A> void let(A a, Consumer<A> f)  {
	f.accept(a);
    }

keigoi

(* try this with 4.02.0+modular-implicits *)
module type Show = sig
  type t
  val show : t -> string
end

implicit module Lam{X:Show} = struct
  type t = [`Var of string | `App of X.t * X.t | `Abs of string * X.t]
  let show : t -> string = function
      |`Var(x) -> x