Skip to content

Instantly share code, notes, and snippets.

View lachezar's full-sized avatar
:shipit:
Type safety lobbyist

Lachezar Yankov lachezar

:shipit:
Type safety lobbyist
42 followers · 209 following
View GitHub Profile
@lachezar
lachezar / Monads.scala
Last active February 12, 2024 15:36
Scala 3 Monad type class for Option and Either
trait Monad[M[_]] {
def pure[A](a: A): M[A]
def flatMap[A, B](m: M[A])(f: A => M[B]): M[B]
}
enum MyOption[+T]:
case None
case Some(value: T)
given Monad[MyOption] with
@lachezar
lachezar / IO.scala
Last active November 21, 2023 13:20
IO implementation exercise
case class IO[A](unsafeRun: () => A):
def map[B](f: A => B): IO[B] =
IO(() => f(unsafeRun()))
def flatMap[B](f: A => IO[B]): IO[B] =
IO(() => f(unsafeRun()).unsafeRun())
val io: IO[Int] = IO(() => {
println("Running side effect!!!")
@lachezar
lachezar / CheckedOptional.java
Created November 15, 2023 13:11
Java Optional that forces you to deal with the missing value on compile-time level instead of the runtime.
package org.example;
import java.util.Optional;
import java.util.Random;
import java.util.function.Supplier;
class NPEChecked extends Exception implements Supplier<NPEChecked> {
private static final NPEChecked instance = new NPEChecked();
@Override
@lachezar
lachezar / currency_example.scala
Last active November 30, 2020 16:07
currency_example.scala
sealed trait Currency
case object Dollar extends Currency
case object Euro extends Currency
case class Money[T <: Currency](value: Int, currency: T) {
def +(that: Money[T]): Money[T] = {
Money[T](this.value + that.value, currency)
}
}
@lachezar
lachezar / currency_example.hs
Last active September 5, 2020 15:12
Currency in Haskell
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
module Main where
newtype USD = USD Int deriving (Show, Num)
newtype EUR = EUR Int deriving (Show, Num)
main :: IO ()
main = do
print $ (USD 12) + (USD 11)
@lachezar
lachezar / words.hs
Created October 5, 2019 19:21
Words in Haskell vs Typescript
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE QuasiQuotes #-}
module Lib
( run
) where
import Text.Regex.PCRE.Heavy
newtype Word' =
@lachezar
lachezar / config.exs
Created October 18, 2016 17:52
sample_config_kafka_ex
# This file is responsible for configuring your application
# and its dependencies with the aid of the Mix.Config module.
use Mix.Config
config :kafka_ex,
# a list of brokers to connect to in {"HOST", port} format
brokers: [
{"localhost", 9092}
],
# the default consumer group for worker processes, must be a binary (string)
@lachezar
lachezar / Devices.java
Last active September 14, 2015 15:17
Helper class to get the consumer friendly device name. Upvote http://stackoverflow.com/a/27836910/1048340
/*
* Copyright (C) 2015 Jared Rummler <jared.rummler@gmail.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
@lachezar
lachezar / bookmarklet
Last active August 29, 2015 14:16
Sans Bullshit Sans bookmarklet
javascript:(function(fontUrl,font,style){if(location.protocol==='https:'){fontUrl='https://lucho-yankov.github.io/assets/fonts/SansBullshitSans.ttf'}else{fontUrl='http://dailyffs.com/sansbullshitsans/SansBullshitSans.ttf';}font='@font-face{font-family:SansBullshitSans;src:url('+fontUrl+');font-weight:normal}';style=document.createElement('style');style.innerHTML=font+'*{font-family:SansBullshitSans;font-feature-settings:\'liga\',\'dlig\';font-variant-ligatures:common-ligatures;}';document.head.appendChild(style);}());
@lachezar
lachezar / dict_to_object.py
Created January 19, 2014 14:03
Python dict to object
config_dict = {
'group1': {
'server1': {
'apps': ('nginx', 'mysql'),
'cpus': 4
},
'maintenance': True
},
'firewall_version': '1.2.3',
'python2.7': True