kif

busypeoples

Phantom types in ReasonML

Introduction

"A phantom type is a parametrised type whose parameters do not all appear on the right-hand side of its definition..." Haskell Wiki, PhantomType

The following write-up is intended as an introduction into using phantom types in ReasonML.

Taking a look at the above definition from the Haskell wiki, it states that phantom types are parametrised types where not all parameters appear on the right-hand side. Let's try to see if we can implement a similar example as in said wiki.

TApplencourt

#!/bin/bash

str_utilisation="$0 (doi|isbn) <value>"
if [ "$#" -ne 2 ];then
    echo ${str_utilisation}
    exit 1
fi

if [ "$1" == "doi" ];then
    doi_raw=$2

TApplencourt

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import os
import sys

try:
    import sqlite3
except:
    print "Sorry, you need sqlite3"
    sys.exit(1)

vext01

Vim+Zathura+Synctex

• In a script called 'vimura':

#!/bin/sh
echo $1
zathura -s -x "gvim --servername $1 -c \"let g:syncpdf='$1'\" --remote +%{line} %{input}" $*

jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD