https://github.com/FujiiMaika/fscd21.git
Tip revision: 521af9c0dd94b169eb02f41aa19d3e01c558f355 authored by Maika Fujii on 24 June 2021, 05:55:35 UTC
Update README.md
Update README.md
Tip revision: 521af9c
eval.ml
open Syntax
open Value
(* Refunctionalized interpreter : eval6 *)
(* initial continuation : v -> s -> t -> m -> v *)
let idc v s t m = match s with
[] ->
begin match t with
TNil ->
begin match m with
MNil -> v
| MCons ((c, s, t), m) -> c v s t m
end
| Trail (h) -> h v TNil m
end
| _ -> failwith "stack error"
(* cons : (v -> t -> m -> v) -> t -> t *)
let rec cons h t = match t with
TNil -> Trail (h)
| Trail (h') -> Trail (fun v t' m -> h v (cons h' t') m)
(* apnd : t -> t -> t *)
let apnd t0 t1 = match t0 with
TNil -> t1
| Trail (h) -> cons h t1
(* f6 : e -> string list -> v list -> c -> s -> t -> m -> v *)
let rec f6 e xs vs c s t m = match e with
Num (n) -> c (VNum (n)) s t m
| Var (x) -> c (List.nth vs (Env.offset x xs)) s t m
| Op (e0, op, e1) ->
f6 e0 xs vs (fun v0 s0 t0 m0 ->
begin match s0 with
VEnv (vs) :: s0 ->
f6 e1 xs vs (fun v1 s1 t1 m1 ->
begin match s1 with
v0 :: s1 ->
begin match (v0, v1) with
(VNum (n0), VNum (n1)) ->
begin match op with
Plus -> c (VNum (n0 + n1)) s1 t1 m1
| Minus -> c (VNum (n0 - n1)) s1 t1 m1
| Times -> c (VNum (n0 * n1)) s1 t1 m1
| Divide ->
if n1 = 0 then failwith "Division by zero"
else c (VNum (n0 / n1)) s1 t1 m1
end
| _ -> failwith (to_string v0 ^ " or " ^ to_string v1
^ " are not numbers")
end
| _ -> failwith "stack error"
end) (v0 :: s0) t0 m0
| _ -> failwith "stack error"
end) (VEnv (vs) :: s) t m
| Fun (x, e) ->
c (VFun (fun v c' s' t' m' -> f6 e (x :: xs) (v :: vs) c' s' t' m')) s t m
| App (e0, e1) ->
f6 e0 xs vs (fun v0 s0 t0 m0 ->
begin match s0 with
VEnv (vs) :: s0 ->
f6 e1 xs vs (fun v1 s1 t1 m1 ->
begin match s1 with
v0 :: s1 ->
begin match v0 with
VFun (f) -> f v1 c s1 t1 m1
| VContS (c', s', t') ->
c' v1 s' t' (MCons ((c, s1, t1), m1))
| VContC (c', s', t') ->
c' v1 s'
(apnd t' (cons (fun v t m -> c v s1 t m) t1)) m1
| _ -> failwith
(to_string v0
^ " is not a function; it can not be applied.")
end
| _ -> failwith "stack error"
end) (v0 :: s0) t0 m0
| _ -> failwith "stack error"
end) (VEnv (vs) :: s) t m
| Shift (x, e) -> f6 e (x :: xs) (VContS (c, s, t) :: vs) idc [] TNil m
| Control (x, e) -> f6 e (x :: xs) (VContC (c, s, t) :: vs) idc [] TNil m
| Shift0 (x, e) ->
begin match m with
MCons ((c0, s0, t0), m0) ->
f6 e (x :: xs) (VContS (c, s, t) :: vs) c0 s0 t0 m0
| _ -> failwith "shift0 is used without enclosing reset"
end
| Control0 (x, e) ->
begin match m with
MCons ((c0, s0, t0), m0) ->
f6 e (x :: xs) (VContC (c, s, t) :: vs) c0 s0 t0 m0
| _ -> failwith "control0 is used without enclosing reset"
end
| Reset (e) -> f6 e xs vs idc [] TNil (MCons ((c, s, t), m))
(* f : e -> v *)
let f expr = f6 expr [] [] idc [] TNil MNil