This Week in D February 28, 2016

Welcome to This Week in D! Each week, we'll summarize what's been going on in the D community and write brief advice columns to help you get the most out of the D Programming Language.

The D Programming Language is a general purpose programming language that offers modern convenience, modeling power, and native efficiency with a familiar C-style syntax.

This Week in D has an RSS feed.

This Week in D is edited by Adam D. Ruppe. Contact me with any questions, comments, or contributions.

Statistics

Major Changes

Release D 2.070.1 came out this week and LDC 1.0.0-alpha1 has been released! Please help testing!

In the community

Community announcements

See more at the announce forum.

Tip of the Week

This week's tip is courtesy of Mahdi Mohammadi and is How to create and use a D package.

To create a D package, you first need to have dub utility (plus D compiler, dmd). You can download pre-compiled dub binaries from here.

Creating a D package

cd ~

mkdir dlibs

cd dlibs

dub init mypack  #this will create a skeleton for your package: mypack

cd mypack

cat dub.sdl  #below is contents of your package

name "mypack"
description "A minimal D application."
copyright "Copyright © 2016, mahdix"
authors "root"
version "1.0.0"
targetType "library"


#the package will have only one source file, located inside source directory

cat source/myfile.d

int add(int x,int y) {
return x+y;
}

#this will compile your package

#although its not necessary but ensures that everything is allright.

dub

Performing "debug" build using dmd for x86_64.
mypack ~master: target for configuration "library" is up to date.
Target is a library. Skipping execution.

Using a D package

To use a D package, we will create an application (which is itself a D package) and define the package we need as it’s dependency. But before that, we need to inform dub where the packages are (which is inside ~/dlibs).

dub add-path ~/dlibs

dub list #this will list all known packages to dub, which will include mypack too

Now lets create a basic project that uses the package:

cd ~

dub init project1

cd project1

cat dub.json #config file can be either sdl, they are equivalent

{
"name": "myproject",
"description": "A little web service of mine.",
"authors": ["Mahdi Mohammadi"],
"homepage": "http://myproject.example.com",
"license": "GPL-2.0",
"targetType": "executable",
"dependencies": {
"mypack": "*"
}
}

#as you notice, we specify "*" as version number of mypack which means: any version

cat source/test.d #this is our only source file which uses add method of mypack

import std.stdio;
import myfile;
void main() {
int x = add(1,4);
writefln("%d", x);
}

#now lets build project1

pwd

~/project1

dub

Performing "debug" build using dmd for x86_64.
mypack ~master: target for configuration "library" is up to date.
myproject ~master: target for configuration "application" is up to date.
To force a rebuild of up-to-date targets, run again with --force.
Running ./myproject
5

#5 is output of the call to add function in mypack

See the author's blog for more from him.

Learn more about D

To learn more about D and what's happening in D: