sudo dnf remove gnome-tour gnome-abrt gnome-calculator gnome-calendar gnome-maps gnome-weather \
rhythmbox gnome-contacts totem gnome-logs gnome-photos gnome-clocks gedit gnome-system-moniter \
gnome-user-docs gnome-screenshot gnome-remote-desktopsudo dnf remove fedora-chromium-config
In this article I’ll tell you about my pure functional library for Software Transactional Memory (STM) that I’ve built in C++. I adopted some advanced functional programming concepts that make it composable and convenient to use. Its implementation is rather small and robust, which differentiates the library from competitors. Let’s discuss what STM is and how to use it.
| private def updateReturning[A, F]( | |
| returningQuery: Query[A, F, C], v: U): SqlStreamingAction[Vector[F], F, Effect.All] = { | |
| val ResultSetMapping( | |
| _, CompiledStatement(_, sres: SQLBuilder.Result, _), CompiledMapping(_updateConverter, _)) = | |
| updateCompiler.run(updateQuery.toNode).tree | |
| val pconv: SetParameter[U] = { | |
| val ResultSetMapping(_, compiled, CompiledMapping(_converter, _)) = | |
| updateCompiler.run(updateQuery.toNode).tree | |
| val converter = _converter.asInstanceOf[ResultConverter[JdbcResultConverterDomain, U]] |
An expression is said to be referentially transparent if it can be replaced with its value without changing the behavior of a program (in other words, yielding a program that has the same effects and output on the same input)
https://en.wikipedia.org/wiki/Referential_transparency
This example is taken from the book "Functional Programming in Scala"
The following is referentially transparent:
scala> val x = "hello, world"
One of the simplest and most recognizable type classes is the semigroup. This type class abstracts over the ability to combine values of a certain type in an associative manner.
Cats provides cats.Semigroup[A] to model semigroups [1].
The combine method takes two values of the type A and returns an A
value.
| object test extends App { | |
| import scala.collection.JavaConversions.asJavaEnumeration | |
| import java.io.{ByteArrayInputStream, SequenceInputStream} | |
| val inputs = Iterator("asdf", "qewr", "wert") | |
| .map(x => new ByteArrayInputStream((x + "\n").getBytes)) | |
| val in = new SequenceInputStream(asJavaEnumeration(inputs)) | |
| Console.setIn(in) | |
| val a = readLine() | |
| val b = readLine() |
| import com.twitter.algebird.{Aggregator, Semigroup} | |
| import com.twitter.scalding._ | |
| import scala.util.Random | |
| /** | |
| * This job is a tutorial of sorts for scalding's Execution[T] abstraction. | |
| * It is a simple implementation of Lloyd's algorithm for k-means on 2D data. | |
| * | |
| * http://en.wikipedia.org/wiki/K-means_clustering |
| %% Shared Ring Buffer | |
| -module(srb). | |
| -export([new/2, push/2, pop/2, pop/1]). | |
| -compile(export_all). | |
| -record(counters, | |
| { clock :: non_neg_integer(), | |
| max_size :: non_neg_integer() }). |
| (defn flip [function] | |
| (fn | |
| ([] (function)) | |
| ([x] (function x)) | |
| ([x y] (function y x)) | |
| ([x y z] (function z y x)) | |
| ([a b c d] (function d c b a)) | |
| ([a b c d & rest] | |
| (->> rest | |
| (concat [a b c d]) |
| The MIT License (MIT) | |
| Copyright (c) 2013 Jamar Parris | |
| Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: | |
| The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. | |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE S |
