Official compiler

[Walter Bright via Digitalmars-d]

On 2/26/2016 11:17 AM, David Nadlinger wrote:
> I was referring to something different in my post, though, as the question
> concerned "low-hanging fruit". The problem there is really just that template
> names sometimes grow unreasonably long pretty quickly. As an example, without
> wanting to divulge any internals, some of the mangled symbols (!) in the Weka
> codebase are several hundred kilobytes in size. core.demangle gives up on them
> anyway, and they appear to be extremely repetitive. Note that just like in
> Steven's post which I linked earlier, the code in question does not involve any
> crazy recursive meta-templates, but IIRC makes use of Voldemort types. Tracking
> down and fixing this – one would almost be tempted to just use standard data
> compression – would lead to a noticeable decrease in compile and link times for
> affected code.

A simple solution is to just use lz77 compression on the strings. This is used 
for Win32 and works well. (I had a PR to put that in Phobos, but it was rejected.)

https://www.digitalmars.com/sargon/lz77.html

As a snide aside, the mangling schemes used by Microsoft and g++ have a built-in 
compression scheme, but they are overly complex and produce lousy results. Lz77 
is simpler and far more effective :-)

An alternative is to generate an SHA hash of the name, which will be unique, but 
the downside is it is not reversible and so cannot be demangled.