This tool demangles symbol names produced by GHC, as per this spec. This can be useful if you’re inspecting haskell object files, etc.

Examples:

multi-except [ listy ] non :| empty Big ( tuple ) Big (# tuple #) Kitchen sink

I find a good way of getting some test data is by using something like this:

readelf --wide -a SOME_HS_LIB | grep -E '^ +[0-9]+' | grep -E -v '\.' | awk '{print $8}'