state.ml~

#use "whileB.ml";;


let rec get (x:int) (s:int list) : int =
  match x,s with
  | 0, v::s -> v
  | i , x::l1 -> get (i-1) l1
  | _, [] -> 0

let tab = 7 :: 8 :: 9 :: 10 :: []

let _ = get (-1) tab


let rec update (s:int list) (v:int) (n:int): int list =
  match v,s with
  | 0   , a :: l1 -> n :: l1
  | 0   , nil     -> n :: nil
  | i, a :: l1 -> a :: (update l1 (i-1) n)
  | i, nil     -> 0 :: (update nil (i-1) n)

let _ = update tab 1 true


let state = 1 :: 0 :: 1 ::[]

let rec evalB = fun b s ->
  match b with
  | Bco(x) -> x=1
  | Bva(v) -> (get (Char.code v - Char.code 'a') s) = 1
  | Bneg(n) -> not (evalB n s)
  | Band(x1, x2) -> (evalB x1 s) && (evalB x2 s)
  | Bor(x1, x2) -> (evalB x1 s) || (evalB x2 s)

let _ = evalB (Bva('b')) state
let _ = evalB (Bneg(Bva('a'))) state
let _ = evalB (Band(Bva('a'), Bva('c'))) state
let _ = evalB (Bor(Bva('b'), Bva('b'))) state

let rec evalW =
  fun w s ->
  match w with
  | Skip -> s
  | Seq(i1,i2) -> evalW i1 s |> evalW i2
  | Affect c b2 -> update s (Char.code c - Char.code 'a')