zacharycarter

Binding to C Libraries with Nim

---

Table of Contents

• Introduction
• C2Nim
• The C Preprocessor
• Pragmas

jsuereth

Here's a short little guide to sbt's build structure.

First off, the key you need to investigate how sbt is building things. Here's a snippet from a build.sbt:

import sbt.Keys._
val bs: sbt.BuildStructure = buildStructure.value

This will give you all the gory details of our build (or builds, as is the case).

non

What is the appeal of dynamically-typed languages?

Kris Nuttycombe asks:

I genuinely wish I understood the appeal of unityped languages better. Can someone who really knows both well-typed and unityped explain?

I think the terms well-typed and unityped are a bit of question-begging here (you might as well say good-typed versus bad-typed), so instead I will say statically-typed and dynamically-typed.

I'm going to approach this article using Scala to stand-in for static typing and Python for dynamic typing. I feel like I am credibly proficient both languages: I don't currently write a lot of Python, but I still have affection for the language, and have probably written hundreds of thousands of lines of Python code over the years.

mbedward

import scala.language.experimental.macros 
import scala.reflect.macros.blackbox.Context

trait Mappable[T] {
  def toMap(t: T): Map[String, Any]
  def fromMap(map: Map[String, Any]): T
}

object Mappable {
  

plesner

-- Given a list of values, returns a list of the differences between
-- neighbouring pairs of values.
nextLevelDiffs (a:b:rest) = (b - a):(nextLevelDiffs (b:rest))
nextLevelDiffs _ = []

-- Given a list of values, returns a list of the differences such that the
-- first element is the 0-level differences, the second the 1-level and so
-- on.
nLevelDiffs [] = []
nLevelDiffs elms = elms:(nLevelDiffs (nextLevelDiffs elms))

Luegg

Desugar Scala Expressions

Use the compiler

scala -Xprint:typer -e "class A(val i: Int)" prints the desugarred expression after the typer phase. Use scala -Xshow-phases to get a list of all phases.

Or use a macro in the REPL

Paste this into a REPL session or in a file loaded with the :load command:

tonymorris

import annotation._

case class Pronunciation(pronounce: String) extends StaticAnnotation
case class Law(name: String, denotation: String) extends StaticAnnotation

trait ~>[F[_], G[_]] {
  def apply[A]: F[A] => G[A]
}

case class Id[A](x: A)

hanny24

// Simple Scala-like for comprehension for rust
macro_rules! comp(
	// base case, using "map"
	(val $id:ident <- $expr:expr $(,if $cond:expr)* $(,let $assign_id:pat = $assign_val:expr)* ,yield $comp:expr) =>
	(
		($expr)$(.filtered(|&$id| $cond))*.map(|&$id| {
			$(let $assign_id = $assign_val;)* $comp
			}
		)

fozziethebeat

/*
 * Copyright (c) 2012, Lawrence Livermore National Security, LLC. Produced at
 * the Lawrence Livermore National Laboratory. Written by Keith Stevens,
 * kstevens@cs.ucla.edu OCEC-10-073 All rights reserved. 
 *
 * This file is part of the S-Space package and is covered under the terms and
 * conditions therein.
 *
 * The S-Space package is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as published

softprops

key independent functions

:=   binds single value
+=   appends single value
++=  appends seq of values

key dependent functions

<<=  binds single value

<+= appends single value