One slightly contrived example would be if you had a function that returned the point of a set closest to another given point.
getClosest :: Set Point -> Point -> Point
You could imagine getClosest build a quadtree internally and that tree wouldn't depend on the second argument. I say slightly contrived because I would probably prefer to make the tree explicit if this was important.
Another example would be if you were wrapping a C-library but were exposing a pure interface. Say you had to create some object and lock a mutex for the first argument but the second was safe. If this was a function intended to be passed to higher-order functions then you might avoid a lot of unnecessary lock contention.
You may be able to achieve something like this with optimisations of your explicit syntax, but argument order is relevant for this. I don't immediately see how it would be achieved without compiling a function for every permutation of the arguments.
getClosest :: Set Point -> Point -> Point
You could imagine getClosest build a quadtree internally and that tree wouldn't depend on the second argument. I say slightly contrived because I would probably prefer to make the tree explicit if this was important.
Another example would be if you were wrapping a C-library but were exposing a pure interface. Say you had to create some object and lock a mutex for the first argument but the second was safe. If this was a function intended to be passed to higher-order functions then you might avoid a lot of unnecessary lock contention.
You may be able to achieve something like this with optimisations of your explicit syntax, but argument order is relevant for this. I don't immediately see how it would be achieved without compiling a function for every permutation of the arguments.