CSS – Can It Be Considered a DSL?

cssdslprogramming-languages

According to Wikipedia, CSS is a style sheet language. However, it's pretty much the only such type of language in use (at least from a web developer's perspective).

When trying to categorize CSS as a language or technology (e.g. for a résumé), would it be acceptable to simply call it a domain-specific language? If you don't think it can, why not?

Best Answer

To answer the question of whether CSS is a domain specific language, according to Martin Fowler, it is. In fact he lists it among examples of DSLs.

You do have to understand that talk about DSLs has been going on for a while now, and Wikipedia's more narrow definition has come along much later in the discussion. Understand that Wikipedia is edited by peers who may or may not have a full grasp of what has been discussed so far. It's definition covers the most common uses for DSLs, and why you may want to create one of your own. However, it does not have a complete article. The fact that it omits markup languages completely is an omission. Perhaps the smart doctorates came along later and redrew the lines--but from the beginning markup languages were included with DSLs in early conversations.

Classifying CSS on a Resume

While CSS is a DSL, you don't want to list it under a section of DSLs on your resume. The most common way to reference CSS is to lump it with HTML.

Related Solutions

Javascript – The Box Model: Internet Explorer vs. W3C

The choice whether to include padding and border into the width or not was arbitrary. The only thing where it mattered was building multi-column layouts. However, you should pay into account the fact that people used tables for layouts at that time anyway. So to them that concern didn't seem important enough and they considered that being able to specify the exact width that the content itself would occupy in CSS seemed a lot more valuable.

For today's developers the situation seem totally different as they use CSS for layouts and they have to deal with CSS boxing model. Thankfully we've got an ability to override boxing rules so in most cases simple rule at the top of your stylesheet works fabulously:

* {
    -mox-box-sizing: border-box;
    box-sizing: border-box;
}

To quote Jeff Kaufman on the subject:

Given that the spec defined it the other way, though, the signal it would have sent to Microsoft to adopt their misinterpretation would have been bad for the web. Microsoft was already using an embrace, extend, and extinguish approach, where they intentionally made products that acted differently from competitors' in order to lock users into the Microsoft versions. They came very close to succeeding with the web: from approximately 2000 to 2005 IE was so popular that many sites designed just for it. Adopting IE's approach here then might have told Microsoft "you can do whatever you want with IE and we'll adjust the standards to make it legal".

So box model fell the victim of power-struggling between W3C and Microsoft.

Criteria for a Mature Programming Language

Acceptance Factors

I'd say a combination of various things, but I don't think they are all required. Some languages considered mature nowadays clearly do not satisfy some of these.

I'd say a combination of:

Tooling:
- mainline: At least one stable "official" or widely-accepted (de-facto or vendor-recommended/supported) tool suite (compiler, interpreter, vm, editor).
- alternative: Some stable and not-so-stable alternatives of the above tooling (closed or open source variants, free or commercial variants, extensions, etc...).
Community: An active , but not necessarily large group of followers and contributors.
Recognition:
- Some degree of recognition and use by some industrial actors (even if in a niche).
- Some degree of recognition in popular culture (even if in a niche).

On Fame, Recognition and Maturity

Note that the differentiator here is on having strong and active criteria validators, not large or numerous ones. To clarify, consider these vastly different examples:

Ruby was for a long-time a language with a large community-backing, an official reference implementation and so forth but could hardly be considered mature until it ironed out some of its rough edges. It was famous before being mature.
On the other hand of the spectrum, some once very-widely used languages (COBOL, FORTRAN...) are now less visible but are still mature in every possible sense. They were once famous and mature.
Also, some niche-languages are in my view definitely mature, inspite of their small (but established) market penetration. Consider Oberon or Limbo. They are mature but never got famous. Others, like R, are relatively famous in that their "niches" aren't really niches (bugs me when people call things like Scala or Clojure "niche languages", which they definitely aren't), though their field of applications are not exactly what you'd call mainstream.

On Stability

What's stable anyways? It's quite relative...

Compliance?
- To the standard (if there's one)?
- To a reference implementation (if there's one)?
Number of bugs? (hardly a good measure)
Use in critical environments?

In general, stability simply means I don't get surprised on a daily basis when going about my average job using the language's toolkit, and I can get definitive answers on what should or should not happen when I attempt to do something with the language and its toolkit, whether it's at the build-time or runtime of my programs.

But stability for someone writing smartphone apps and stability for someone writing medical or avionics systems is a different kind of bird.