Compilation speed of modules/functors

Compilation speed of modules/functors

[Jacques Carette]

Are there known issues with compilation speed of heavily functorized 
code?  My code used to use a lot of records, but that was not very 
extensible, so I switched to using modules and functors.  Now the 
compilation time has gone from << 1 second to 5-6 seconds (on my slow 
laptop).  While not the end of the world, this still surprised me.  Are 
there known issues in this area?  Known pitfalls and work-arounds?

The actual codes are in MetaOCaml, but I did some experiments in pure 
Ocaml and got the same results, so it is not due to MetaOCaml (sorry, 
these are no longer available).  The curious can look at
http://www.metaocaml.org/examples/gausselim/
for record-based code and
http://www.cas.mcmaster.ca/~carette/metamonads/
for functor-based code.

Jacques

Re: [Caml-list] Compilation speed of modules/functors

[Christian Lindig]

On Aug 22, 2005, at 6:03 PM, Jacques Carette wrote:
> Are there known issues with compilation speed of heavily functorized 
> code?

At least the Lua-ML interpreter is another example.

	http://www.cminusminus.org/rsync/dist/
	http://www.cminusminus.org/rsync/qc--/lua/
	http://www.cminusminus.org/rsync/qc--/lua/lualib.nw

The construction of the interpreter is discussed in these papers:
	
	http://www.eecs.harvard.edu/~nr/pubs/embed-abstract.html
	http://www.eecs.harvard.edu/~nr/pubs/mania-abstract.html

Module lualib.nw links together the library for the interpeter and uses 
heavily functorized code. It takes also several seconds to compile this 
otherwise small module.

-- Christian