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@martinwicke
martinwicke / automobile.ipynb
Last active January 9, 2022 08:14
Estimator demo using Automobile dataset
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@Centaur
Centaur / tailrec2fold.scala
Last active December 19, 2016 04:34
Tailrec to Fold
package org.snippets
import scala.collection.immutable.Stream.#::
import scala.util.{Failure, Success, Try}
class InsufficientParametersException(message: String) extends RuntimeException(message)
object Tailrec2Fold {
type RpnModel = String
type CalculationState = (String, String)

Getting Started in Scala

This is my attempt to give Scala newcomers a quick-and-easy rundown to the prerequisite steps they need to a) try Scala, and b) get a standard project up and running on their machine. I'm not going to talk about the language at all; there are plenty of better resources a google search away. This is just focused on the prerequisite tooling and machine setup. I will not be assuming you have any background in JVM languages. So if you're coming from Python, Ruby, JavaScript, Haskell, or anywhere…  I hope to present the information you need without assuming anything.

Disclaimer It has been over a decade since I was new to Scala, and when I was new to Scala, I was coming from a Java and Ruby background. This has probably caused me to unknowingly make some assumptions. Please feel free to call me out in comments/tweets!

One assumption I'm knowingly making is that you're on a Unix-like platform. Sorry, Windows users.

Getting the JVM

anonymous
anonymous / response.md
Created October 6, 2016 14:29
Response to recent InfoQ article

Most of what's written in this article is deliberately biased and wrong. It is yet another in the stream of Scala-hating posts that people. I analyze the article below:

  1. TIOBE index is a metric based on search engine ranking policies and can be intentionally or unintentionally gamed.

    https://blog.timbunce.org/2009/05/17/tiobe-index-is-being-gamed/

On these rankings, Scala is quite high:

Applied Functional Programming with Scala - Notes

Copyright © 2016-2018 Fantasyland Institute of Learning. All rights reserved.

1. Mastering Functions

A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.

val square : Int => Int = x => x * x
@djspiewak
djspiewak / 0introduction.md
Last active November 28, 2023 15:03
Scala Collections Proposal

Collections Redesign Proposal

I'm going to start off by motivating what I'm doing here. And I want to be clear that I'm not "dissing" the existing collections implementation or anything as unproductively negative as that. It was a really good experiment, it was a huge step forward given what we knew back in 2.8, but now it's time to learn from that experiment and do better. This proposal uses what I believe are the lessons we can learn about what worked, what didn't work, and what is and isn't important about collections in Scala.

This is going to start out sounding really negative and pervasively dismissive, but bear with me! There's a point to all my ranting. I want to be really clear about my motivations for the proposal being the way that it is.

Problems

Generic Interfaces

@davegurnell
davegurnell / TypeclassDemo.scala
Created October 6, 2015 14:53
Example of the type class pattern in Scala
object TypeclasseDemo {
// The parts of the type class pattern are:
//
// 1. the "type class" itself -- a trait with a single type parameter;
//
// 2. type class "instances" for each type we care about,
// each marked with the `implicit` keyword;
//
// 3. an "interface" to the type class -- one or more methods
@odersky
odersky / A simpler way to returning the "current" type in Scala.
Last active April 5, 2024 13:34
A simpler way to returning the "current" type in Scala.
/** This is in reference to @tploecat's blog http://tpolecat.github.io/2015/04/29/f-bounds.html
* where he compares F-bounded polymorphism and type classes for implementing "MyType".
*
* Curiously, the in my mind obvious solution is missing: Use abstract types.
*
* A lot of this material, including an argument against F-bounded for the use-case
* is discussed in:
*
* Kim B. Bruce, Martin Odersky, Philip Wadler:
* A Statically Safe Alternative to Virtual Types. ECOOP 1998: 523-549
@pathikrit
pathikrit / SudokuSolver.scala
Last active April 12, 2024 15:00
Sudoku Solver in Scala
val n = 9
val s = Math.sqrt(n).toInt
type Board = IndexedSeq[IndexedSeq[Int]]
def solve(board: Board, cell: Int = 0): Option[Board] = (cell%n, cell/n) match {
case (r, `n`) => Some(board)
case (r, c) if board(r)(c) > 0 => solve(board, cell + 1)
case (r, c) =>
def guess(x: Int) = solve(board.updated(r, board(r).updated(c, x)), cell + 1)
val used = board.indices.flatMap(i => Seq(board(r)(i), board(i)(c), board(s*(r/s) + i/s)(s*(c/s) + i%s)))
@patriciogonzalezvivo
patriciogonzalezvivo / PythonSetup.md
Created October 7, 2014 23:17
How to install Python correctly on Mac OSX

Install Homebrew

ruby -e "$(curl -fsSL https://raw.github.com/mxcl/homebrew/go)"

Add PATH to ~/.bash_profile and ~/.zshrc

export PATH=/usr/local/bin:$PATH