Is it possible to speed up the F# compiler?

Question

As of F# 1.9.6.16 and Mono 2.4.2.3 I am failing to AOT the F# assemblies, getting a segmentation fault. fsi is barely usable (and sometimes crashes), and fsc is quite painfully slow. Under windows, F# is not the fastest compiler either. Is there anything to help the situation?

Answer 1

The best way to help this situation is to file bugs. If you have a particular project or environment which is having a significant slow down I highly encourage you to file a bug. Often times real world customer scenarios are very instructive in tracking down performance problems in products.

F#, like the rest of the languages in visual studio, process customer bugs filed via Microsoft's connect website.

• http://connect.microsoft.com

(EDIT: In the specific case of F#, you are also welcome to email [email protected].)

Answer 2

I just found a way to write F# scripts on Linux that do not rely on fsi but rather automatically recompile and are therefore reasonably fast:

Given /usr/local/bin/fsx:

#!/bin/bash
src=$1
tgt=$src.exe
if [[ $src -nt $tgt ]]
then
    fsc $src -o $tgt >/dev/null && exec mono $tgt
else
    exec mono $tgt
fi

One can write scripts that omit the shebang, relying on the default shell:

#light (*
    exec fsx $0
*)

printfn "Hello, world!"

When run, the shell skips the first line thinking it is a comment, and runs exec fsx $0, which compiles the script with fsc if the executable is out of date, and then runs it. For F#, the shell command is just a comment.