F-liter Supercompiler

Debug variant.

A reimplementation of the Bollingbroke & Peyton-Jones (2010) compiler for the F-liter language in an attempt to understand it better. Currently packaged as a library and as is.

Try;

$ ghci Supercompiler
λ> ex_mapmap
main  = let x = Nil
        in sc x
sc x = let y = inc
       in
          let z = map y x
          in map y z
map x y = case y of
            Nil  -> Nil
            Cons z p -> let
                            q = x z
                            r = map x p
                        in Cons q r
inc x = let y = 1
        in x + y
λ> sc_wrapper ex_mapmap ("sc", lam "xs" $ fun "sc" @: "xs")
...

It will supercompile the function sc of program ex_mapmap with an unknown input.

Extra debug features

To aid debugging, the Debug.RocketFuel library prematurely terminates supercompilation when a predetermined "fuel" supply is depleted. This a very unsafe implementation of the concept introduced in Whalley's (1994) Automatic isolation of compiler errors.

By default, the fuel tank is infinite (i.e. Nothing).

• fuelTank is a global variable.
• disableTank creates infinite fuel.
• fillTank n creates a finite pool of n units of fuel.
• consumeFuel empty full will consume 1 unit of fuel. If the tank is depleted, it returns empty, otherwise full.
• readTank returns the fuel tank value.