Feature discussion: __traits(getSource, function)

[Adam D. Ruppe]

I have what might be a weird request here: a way to get the source code of a
function (or maybe class, etc. too) out of the compiler as a string literal.

Using existing features, I was able to think up a hacky solution: use
__FILE__, __LINE__, and string import to get the source and read it in. But my
implementation was bug riddled, needed extra code at the function, and relied
on conventions.

So I'd prefer something built in - a trait addition could do the job. I looked
at the compiler's source, and it doesn't seem to keep all the needed info
around, but I imagine it would be a lot easier for it to figure this out than
doing it with mixins.


Why would this be useful? My specific case is taking a D function and
translating it into javascript at run time, so I can print it out to the
browser and run it there too. (naturally, this requires some conventions and
simplifcation in the code to work anyway, so my hacky solution works for me).

Other advantages might be mixing it with string mixins to edit code at compile
time.


Honestly, I'm not sure about what else it would be good for. Can anyone think
of something compelling enough for me to dive into the dmd source and see
about doing it myself?

I started typing this excited about the possibilities, but I ended up changing
my mind while typing the short list of advantages... but let's discuss it. Any
ideas on how it would be useful?

Perhaps a simpler alternative would be __traits(sourceFile) and sourceLine -
to mimic my current solution.