D to Javascript converter (a hacked up dmd)

[node]

Does this mean I can do node.js in D? :)

On Monday, 27 February 2012 at 03:51:22 UTC, Adam D. Ruppe wrote:
> https://github.com/downloads/adamdruppe/dtojs/dtojs.zip
>
> Daniel Murphy's microd fork of dmd, meant to output C,
> made me realize it'd be fairly easy to use that same method
> for other languages too.
>
> So, I spent some time these last two weekends making it work
> to put out Javascript.
>
>
> See below for a copy/paste of the readme on how to get started.
>
> A live demo:
> http://arsdnet.net/dtojs/test.html
>
> D source code:
> http://arsdnet.net/dtojs/microd.d
>
>
>
> As you can see, a lot of things work: functions, main,
> most the operators, loops, if, basic data types,
> even structs, classes (including inheritance), and exceptions.
>
>
> Take a look at the generated javascript
> http://arsdnet.net/dtojs/microd.js
>
> It looks messy, since it uses mangled names almost everywhere.
> (if you replace the mangled names with shorter things, it cuts
> the size down by like 60%. Or, you can gzip it for a 10x 
> reduction.
>  See tools/mangledown.d in the zip, but this is raw so you can 
> see
> what it makes.)
>
>
>
> For classes, it creates a vtable and some run time type 
> information
> on the Javascript object. This allows dynamic casts and virtual
> functions to work like you expect in D.
>
> You can see _Dmain in the middle of the file, and at the bottom,
> you can see it is called if present, so you can have one or not 
> have
> one at your preference.
>
> As you scroll down, you'll see the methods. Since I forked a C
> generator, they are made and usually called as free functions,
> but extern(js) (see below) are made as object properties.
>
>
> Not so obvious is the runtime that's mixed in there.
>
> Here's the D source code:
> http://arsdnet.net/dtojs/object.d
>
>
> It's pretty simple code. extern(js) works to let you - and other
> JS things - easily interact with the outside world, since it
> turns off mangling while letting you define things like loose
> variadics.
>
> There is no handwritten Javascript except for the if(_Dmain) at
> the end. The rest of the runtime and library is written in D.
>
>
>
> Speaking of library, I started something there too.
>
> http://arsdnet.net/dtojs/browser/
>
> the browser package generates no Javascript code. It simply
> binds to existing functionality so D can use it in a more
> structured manner. (object.d generates ~14kb of code when
> raw. If you run mangledown on it, it goes down to about 6.)
>
> browser.document provides some access to the browser DOM.
>
> http://arsdnet.net/dtojs/std/
>
> The std package is a kind of Phobos library, meant to make
> source-compatible code with regular D stuff. It generates some
> javascript.
>
>
> I don't want to use the real Phobos though because it is fairly
> large, and won't take advantage of the browser's existing 
> library
> functions. It *might* work in here though; I haven't tried.
>
>
>
> The browser package makes no attempt at cross browser 
> compatibility,
> but you can test for functions like you would in real JS:
>
> if(&document.querySelector) { we have it }
>
>
>
> If I start to use this thing seriously, I might provide a 
> library
> wrapper that does this kind of thing.
>
>
>
>
>
>
> Anyway, it works pretty well in the trivial tests I've done
> so far, but I haven't used it for anything more serious.
>
>
>
> Kinda cool though, and hasn't been that hard. The dmd compiler
> isn't so bad to hack up once you get to know it.
>
> Combined with the stuff others and I have already done for
> D on the server, we might just be coming up on web apps that
> use the same D everywhere!
>
> ========
> Here's how to use it:
>
> First, copy in the backend folder from the dmd.zip you
> get from Digital Mars.
>
> (You need it to compile, but I don't have a license to
> distribute it myself.)
>
>
> Then, run make to build the hacked dmd.
>
>
>
> When its done, change into the "test" directory and
> start to play. The makefile there shows how to build
> some javascript.
>
> ../dmd -md yourfile.d
>
> and optionally you can use my library in there from
> test/browser and test/std.(add std/*.d to the dmd
> command line to make sure its code is generated in.)
>
> You can ignore most the messages it spams out; it
> will do its best to generate the file anyway.
>
> test/browser is the kind of core runtime to this,
> in addition to object.d.
>
> object.d - the stuff D expects and the basic JS language
> constructs
>
> browser/*.d - bindings to objects and functions the browser 
> provides
> such as the DOM.
>
> Most global functions in the browser are found in 
> browser/window.d.
>
>
> std/*.d - just super minimal wrappers to browser functions laid 
> out
> more like Phobos.