Proxy assoc functions to OCaml stdlib?

[tekknolagi]

eff/src/utils/assoc.ml

Line 7 in 4c6bc57

let rec lookup x = function

Many of the functions in assoc.ml can be proxied to OCaml stdlib:

• Assoc.lookup => List.assoc_opt
• Assoc.remove => List.remove_assoc
• Assoc.iter => List.iter (has been done)
• Assoc.kmap => List.map
• Assoc.fold_left => List.fold_left (has been done)
• Assoc.fold_right => List.fold_right (has been done)
• Assoc.length => List.length (has been done)

and so on. Is there a reason these are re-implemented by hand?

[matijapretnar]

I don't recall exactly, but my guess is:

• List.assoc_opt wasn't around until recently
• We probably didn't bother to look for List.remove_assoc
• If I recall correctly, List.map used to be implemented as

let rec map f = function
| [] -> []
| x :: xs -> f x :: map f xs

and then it depends on the byte/native code whether f x or map f xs is evaluated first. Since we used quite some effectful functions f in the implementation, we decided to write our own implementation that guarantees the order of evaluation.