I agree with all that, particularly the bit about the c ffi call. It's more relevant to compare Rust with C and C++, as Rust is a language that could reasonably display C for the ffi call.

But then remember that @wyager is claiming

>80% as fast as hand-optimized C for only 10% of the effort of hand-optimized C

If it's really only 10% of the effort then one shouldn't really have "to work on it" to get semi-decent performance.

A more modest claim of say:

50% as fast as hand-optimized C for only 20% of the effort of hand-optimized C

would have been more credible and still a big win for many use cases.

Tried my hand at the knucleotide[1] one. Lifted the algorithm from the fastest rust solution. As optimization I dropped some Unpack pragmas and strictness annotations, used Data.Hashtable.Cuckoo for in-place updating hash tables because that seemed necessary for the task, and added naive parallelization via

   let outputs = map (exec content) tasks `using` parList rseq

That got around 24 seconds which seems acceptable for a fairly straightforward solution that is around half the size of the rust one I copied. Might try to optimize later.

[1]: http://benchmarksgame.alioth.debian.org/u64q/knucleotide.htm...

That pi-digits program does not "build on [your] machine no problem".

It cannot.

The line "main = putStr.pidgits.read.head =<< getArgs" has been commented out because the program author has optimised-away some of the work that must be done.

Fair enough, I only checked the two knucleotide programs which both failed because of missing dependencies.

>> The make errors are a bit weird because the programs build on my machine no problem. <<

My fault (except for pi-digits and regex-redux).

I neglected to work-through the force-reinstalls that inevitably follow my update of the GHC compiler.

Done.