fetburner

Require Import Arith Div2 Omega Recdef.

Function bsearch (p : nat -> bool) n { wf lt n } :=
  match n with
  | O => 0
  | _ =>
      let m := div2 n in
      if p m then bsearch p m
      else S m + bsearch (fun x => p (S m + x)) (n - S m)
  end.

yamashita1238

:- use_module(library(socket)).

write_atom(Stream,Atom) :-
  atom_codes(Atom,Codes),
  write_codes(Stream,Codes).

write_codes(_,[]) :- !.
write_codes(Stream,[Code|Tail]) :-
  put_code(Stream,Code),
  write_codes(Stream,Tail).

camlspotter

(*

OCaml translation of the ideas explained in http://fumieval.hatenablog.com/entry/2014/09/22/144401

To emulate the higher kinded polymorphism, the technique used explained in https://ocamllabs.github.io/higher/lightweight-higher-kinded-polymorphism.pdf

*)

module StateMonad = struct
  type ('s, 'a) m = 's -> 's * 'a

leque

各言語での Map, Dictionary 的なものの名前

CommonLisp:

hash-table

Scheme:

hash-table (SRFI-69), hashtable (R6RS Scheme)

Haskell:

Map

OCaml:

gakuzzzz

Scala の省略ルール早覚え

このルールさえ押さえておけば、読んでいるコードが省略記法を使っていてもほぼ読めるようになります。

メソッド定義

def concatAsString(a: Int, b: Int): String = {
  val a_ = a.toString();
  val b_ = b.toString();

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.

tsdeng

Basic Support

1. Install ctags-exuberant
   • add stuff as listed in http://leonard.io/blog/2013/04/editing-scala-with-vim/ to ~/.ctags
2. Install gnu global
   • brew install global --with-exuberant-ctags
   • add following line in bash export GTAGSCONF=/usr/local/share/gtags/gtags.conf
   • edit gtags.conf, in the exuberant-ctags section, add following line :langmap=Scala:.scala:\

omasanori

R'0'RSを読む

これはLisp Advent Calendar 2013の19日目の文章です。

はじめに

表題に出てくるR'0'RSは正式な名称ではありません。表題で私がR'0'RSと呼んでいる文章はSchemeの言語仕様を記述した報告書、いわゆるRnRSの元祖といえる"Scheme: An Interpreter for Extended Lambda Calculus"です。この文章はAI Memo 349としても知られています。以下ではAIM 349と呼びます。

KOBA789

var util = require('util');

function Nothing () {}

Object.Nothing = Nothing;

Array.prototype.maybeMap = function (callback, thisArg) {
  var T, A, k;
  if (this == null) {
    throw new TypeError(" this is null or not defined");

kazuho

// based on http://labs.cybozu.co.jp/blog/kazuho/archives/2007/05/coopthread.php
function get_all(urls) {
  runnable(function (next) {
    for (var i = 0; i < urls.length; i++) {
      // build request
      var xhr = new XMLHttpRequest();
      xhr.open("get", urls[i], true);
      xhr.onreadystatechange = function () {
        if (xhr.readyState == 4)
          next(xhr.responseText);