Compilation times are a bit slow

[ruhler]

The Smten compilation times can be a bit slow, especially when compiling things like happy generated grammars. Is there anything we can do to improve these compile times?

[ruhler]

If you run smten with '-v', you can see where most of the time is being spent: outputting the generated haskell code for large files.

[ruhler]

I switched to using wl-pprint-text for the pretty printer, which seems to speed things up a bit. Now the problem seems to be less pretty printing performance, and more overall size of the generated output.

Some ideas for how to improve things:

• don't fully qualify every name!
• do (\a b -> ...), instead of (\a -> (\b -> ...))
• do (a, b), instead of ((,) a b) for types, patterns, and expressions
• avoid unnecessary explicit types?
• do (f x y) instead of ((f x) y)

[ruhler]

I tried everything listed above except for avoiding unnecessary types. Using shorter qualified names made the biggest difference: 16s reduced to 14.4s. Now pretty printing is certainly not the bottleneck.

Most time now seems to be spent in:

• Doing the core translation
• ghc type checking, simplification, and code generation for the generated code.

I'm not sure how to improve this.