Files
olisp/lib/vm/native.ml
T

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OCaml

(* This file implements native functions of the VM runtime.
Stuff like printing to the screen, file I/O etc will be implemented
here.
*)
open Types
type numeric_val =
| NInt of int
| NDouble of float
let to_numeric = function
| Int x -> NInt x
| Double x -> NDouble x
| v -> failwith ((print_value v) ^ " is not a numeric value")
let of_numeric = function
| NInt x -> Int x
| NDouble x -> Double x
let numeric_generic fi fd = function
| NInt x -> (function
| NInt y -> NInt (fi x y)
| NDouble y -> NDouble (fd (float_of_int x) y))
| NDouble x -> (function
| NInt y -> NDouble (fd x (float_of_int y))
| NDouble y -> NDouble (fd x y))
let numeric_add = numeric_generic (+) (+.)
let numeric_sub = numeric_generic (-) (-.)
let numeric_mul = numeric_generic ( * ) ( *. )
let numeric_div = numeric_generic ( / ) ( /. )
let builtin_print (v : Types.value ref list) =
List.iter (fun r -> print_endline (print_value !r)) v;
Types.Nil
let builtin_add (vs : Types.value ref list) =
of_numeric (List.fold_left numeric_add (NInt 0) (List.map (fun r -> to_numeric !r) vs))
let builtin_sub (vs : Types.value ref list) =
match vs with
| f :: [] -> of_numeric (match (to_numeric !f) with
| NInt x -> NInt (Int.neg x)
| NDouble x -> NDouble (Float.neg x))
| f :: rest -> of_numeric (List.fold_left numeric_sub (to_numeric !f) (List.map (fun r -> to_numeric !r) rest))
| [] -> failwith "invalid number of arguments for subtraction"
let builtin_mul vs =
of_numeric (List.fold_left numeric_mul (NInt 1) (List.map (fun r -> to_numeric !r) vs))
let table = [|
builtin_print;
builtin_add;
builtin_sub;
builtin_mul
|]