{"id":211,"date":"2016-09-09T14:04:20","date_gmt":"2016-09-09T14:04:20","guid":{"rendered":"http:\/\/dlang.org\/blog\/?p=211"},"modified":"2021-10-08T11:10:18","modified_gmt":"2021-10-08T11:10:18","slug":"gsoc-report-dstep","status":"publish","type":"post","link":"https:\/\/dlang.org\/blog\/2016\/09\/09\/gsoc-report-dstep\/","title":{"rendered":"GSoC Report: DStep"},"content":{"rendered":"

Wojciech Sz\u0119szo\u0142 is a Computer Science major at the University of Wroc\u0142aw. As part of Google Summer of Code 2016, he chose to make improvements to Jacob Carlborg’s DStep<\/a>, a tool to generate D bindings from C and Objective-C header files.<\/em><\/p>\n

\n

\"GSoC-icon-192\"It was December of last year and I was writing an image processing project for a course at my university<\/a>. I would normally use Python<\/a>, but the project required some custom processing, so I wasn’t able to use numpy<\/a>. And writing the inner loops of image processing algorithms in plain Python isn’t the best idea. So I decided to use D.<\/p>\n

I’ve been conscious about the existence of the D language for as long as I can remember, but I’d never convinced myself before to try it out. The first thing I needed to do was to load an image. At the time, I didn’t know that there is a DUB repository<\/a> containing bindings to image loading libraries, so I started writing bindings to libjpeg<\/a> by myself. It didn’t end very well, so I thought there should be a tool that will do the job for me. That’s when I found DStep<\/a> and htod<\/a>.<\/p>\n

Unluckily, the capabilities of DStep weren’t satisfying (mostly the lack of any kind of support for the preprocessor) and htod didn’t run on Linux. I ended up coding my project in C++, but as GSoC (Google Summer of Code<\/a>) was lurking on the horizon, I decided that I should give it a try with DStep. I began by\u00a0contacting Craig Dillabaugh (Ed. Note: Craig volunteers to organize GSoC projects using D<\/em>) to learn if there was any need for developing such a project. It sparked some discussion on the forum<\/a>, the idea was accepted, and, more importantly, Russel Winder agreed to be the mentor of the project. After some time I needed to prepare and submit an official proposal. There was an interview and fortunately I was accepted.<\/p>\n

The first commit I made for DStep is dated to February, 1. It was a proof of concept that C preprocessor definitions can be translated to D using libclang<\/a>. Then I improved the testing framework by replacing the old Cucumber-based<\/a> tests with some written in D. I made a few more improvements before the actual GSoC coding period began.<\/p>\n

During GSoC, I added support for translation of preprocessor macros (constants and functions). It required implementing a parser for a small part of the C language as the information from libclang was insufficient. I implemented translation of comments, improved formatting of the output code (e.g. made DStep keep the spacing from C sources), fixed most of the issues from the GitHub issue list<\/a> and ported DStep to Windows. While I was coding I was getting support from Jacob Carlborg. He did a great job by reviewing all of the commits I made. When I didn’t know how to accomplish something with D, I could always count on help on forum.dlang.org<\/a>.<\/p>\n

DStep was the first project of such a size that I coded in D. I enjoyed its modern features, notably the module system<\/a>, garbage collector<\/a>, built-in arrays<\/a>, and powerful templates<\/a>. I used unittest blocks<\/a> a lot. It would be nice to have named unit tests, so that they can be run selectively. From the perspective of a newcomer, the lack of consistency and symmetry in some features is troubling, at least before getting used to it. For example there is a built-in hash map<\/a> and no hash set, some identifiers that should be keywords starts with @<\/code>\u00a0(Ed. Note: see the Attributes documentation<\/a><\/em>), etc. I was very sad when I read that the in<\/code> keyword is not yet fully implemented. Despite those little issues, the language served me very well overall. I suppose I will use D for my personal toy projects in the future. And for DStep of course. I have some unfinished business with it :).<\/p>\n

I would like to encourage all students to take part in future editions of GSoC. And I must say the D Language Foundation<\/a> is a very good place to do this. I learned a lot during this past summer and it was a very exciting experience.<\/p>\n","protected":false},"excerpt":{"rendered":"

Wojciech Sz\u0119szo\u0142 is a Computer Science major at the University of Wroc\u0142aw. As part of Google Summer of Code 2016, he chose to make improvements to Jacob Carlborg’s DStep, a tool to generate D bindings from C and Objective-C header files. It was December of last year and I was writing an image processing project […]<\/p>\n","protected":false},"author":8,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[12,19,9],"tags":[],"_links":{"self":[{"href":"https:\/\/dlang.org\/blog\/wp-json\/wp\/v2\/posts\/211"}],"collection":[{"href":"https:\/\/dlang.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dlang.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dlang.org\/blog\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/dlang.org\/blog\/wp-json\/wp\/v2\/comments?post=211"}],"version-history":[{"count":4,"href":"https:\/\/dlang.org\/blog\/wp-json\/wp\/v2\/posts\/211\/revisions"}],"predecessor-version":[{"id":305,"href":"https:\/\/dlang.org\/blog\/wp-json\/wp\/v2\/posts\/211\/revisions\/305"}],"wp:attachment":[{"href":"https:\/\/dlang.org\/blog\/wp-json\/wp\/v2\/media?parent=211"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dlang.org\/blog\/wp-json\/wp\/v2\/categories?post=211"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dlang.org\/blog\/wp-json\/wp\/v2\/tags?post=211"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}