javascript (was Re: Java > Scala -> new thread: GUI for D)

[Jacob Carlborg]

On 2011-12-04 21:17, Adam D. Ruppe wrote:
> Jacob Carlborg Wrote:
>> I hide JavaScript behind CoffeeScript, makes it a bit more usable.
>
> If you like the idea there, but want something a lot more conservative,
> in my html.d (in here: https://github.com/adamdruppe/misc-stuff-including-D-programming-language-web-stuff )
> there's now a JavascriptMacroExpander class which pre-processes javascript.
>
> The only build in function it provides right now is foreach() (just because I find
> it's lack to be the easiest thing to take care of...) but the macro system might
> be useful too for certain things.
>
> Again, it's just a preprocessor, so you drop stuff like this into the middle of
> regular js code:
>
> ¤foreach(element; document.querySelectorAll("p")) {
>       element.style.color = "red";
> }
>
> converts to
>
>      var arsd_foreach_loop_temporary_2 = document.querySelectorAll("p");
>      for(var arsd_foreach_loop_counter_1 = 0; arsd_foreach_loop_counter_1<  arsd_foreach_loop_temporary_2.length; arsd_foreach_loop_counter_1++) {
>               var element = arsd_foreach_loop_temporary_2[arsd_foreach_loop_counter_1];
>               element.style.color = "red";
>      }
>
>
> which I realize is an ugly mess but just because I used long names for the temporaries.
> It: a) puts the iterable in it's own var, b) does a for loop over it, c) sets up a local for
> the iterated thing inside the loop and d) pastes your code in there.
>
>
> (that symbol before foreach is the one I did to denote a macro. I put it
> on a hotkey in my editor... but I wanted something that I'd never use in
> normal code, to keep the preprocessor both dead simple and out of the
> way.)
>
>
> You can also define your own macros and variables in the JS code
> or as delegates in D.
>
>
> I actually wrote this macro system for css, but it works pretty well
> here too. (html.d also includes a CssMacroExpander, which runs this
> and a de-nesting function.)

Maybe you should take a look at SASS, it has if-statements, for-loops, 
functions, mixins, variables and other useful features. Two syntaxes are 
available, one which is a superset of CSS (SCSS) and one which doesn't 
use semicolon and uses indentation for scopes (SASS).

http://sass-lang.com/

> This is pretty new stuff, so I'll probably be adding more functions
> as I use it more.

I think CoffeeScript works really well, it's been around a while and 
it's the default way to handle JavaScript in Rails 3.1 and later 
versions (SASS is the default way of handling CSS). Rails is what I'm 
using for web development.

-- 
/Jacob Carlborg