Tatsuya Hirose lotz84

できるようになったこと

Curl コマンドの基礎
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git commit
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hubotをherokuで動かす
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while true do done

できるようになったこと

git の仕組みの薄い理解
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できてなくてやりたいこと

bottle-yotoslack

インスコしたもの

python 3.2

Does Haskell make promises it can't keep?

or The big problem with wrapping numeric types

When coding financial calculations, it's common to have a variety of numeric values such as Quantity, Price, Amount and so on. In quant finance, these usually refer to the Price observed in the market, a Quantity of shares. A Quantity of shares all traded at a given Price in a given currency will give you an Amount of that currency (the total value of the trade).

It's simple and fun exercise to write the functions you'd need to perform all the correct ways of combining Price, Quantity and Amount. There are a couple of things that don't work as you might expect (e.g., multiplication is ok but you need to think about division semantics.).

Many Haskell tutorials encourage the coder to wrap Double and Int in newtypes like this, so the compiler can help by detecting incorrect combinations of the different types, and so the code documents itself better. e.g.

Löb with error handling

löb is a well-known function in Haskell for implementing spreadsheet-like behaviors and tying the knot. It is defined as:

loeb :: Functor f => f (f a -> a) -> f a
loeb fs = xs
  where xs = fmap ($ xs) fs

	#include <cstdio>
	#include <ratio>

	template <typename R, intmax_t N>
	struct ratio_pow {
	using prev = typename ratio_pow<R, N-1>::value;
	using value = std::ratio<R::num * prev::num, R::den * prev::den>;
	};

	template <typename R>

	"""
	Minimal character-level Vanilla RNN model. Written by Andrej Karpathy (@karpathy)
	BSD License
	"""
	import numpy as np

	# data I/O
	data = open('input.txt', 'r').read() # should be simple plain text file
	chars = list(set(data))
	data_size, vocab_size = len(data), len(chars)

	Set Implicit Arguments.
	Unset Strict Implicit.

	Require Import Setoids.Setoid Morphisms.
	Generalizable All Variables.

	Class Setoid :=
	{
	carrier: Type;
	equal: carrier -> carrier -> Prop;

	import System.Random
	import Control.Monad

	main :: IO()
	main = print showKiyoshi

	getRandomInt :: IO Int
	getRandomInt = getStdRandom $ randomR (0,1) :: IO Int

	text :: [String]

	import System.Random

	main = do
	gen1 <- getStdGen
	let rand = getRandom gen1
	print . showKiyoshi . getKiyoshi $ rand

	text :: [String]
	text = ["zun", "doko", "kiyoshi"]