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|
open Util
open Khs_ast
type kprog =
{
pinstr: khs_stmt array;
plabels: int Smap.t;
}
type kbval =
| VNone
| VInt of int
| VBool of bool
| VStr of string
type kval =
| Single of kbval
| Many of kbval Smap.t
type chanid = kbval
type kprocstatus =
| PSExec
| PSSend of chanid * kval
| PSRecv of chanid
| PSExecRecvd of kval
| PSDone
type kproc =
{
xspawn: kproc -> int -> unit;
xnewchan: kproc -> kval;
xprog: kprog;
mutable xvals: kbval Smap.t;
mutable xstatus: kprocstatus;
mutable xpos: int
}
let psep = "\\"
let framevar = "#"
(* Procedures on values *)
(* Strange semantics : all type conversions are allowed *)
let int_of_kbval = function
| VInt i -> i
| VBool true -> 1
| VBool false -> 0
| VNone -> 0
| VStr s -> int_of_string s
let str_of_kbval = function
| VInt i -> string_of_int i
| VBool true -> "1"
| VBool false -> "0"
| VNone -> ""
| VStr s -> s
let bool_of_kbval = function
| VInt i -> i <> 0
| VBool b -> b
| VNone -> false
| VStr s -> (int_of_string s) <> 0
let kval_of_kbval v = Single v
let kbval_of_kval = function
| Single v -> v
| Many a ->
try Smap.find "" a
with Not_found -> VNone
let int_of_kval v = int_of_kbval (kbval_of_kval v)
let bool_of_kval v = bool_of_kbval (kbval_of_kval v)
let str_of_kval v = str_of_kbval (kbval_of_kval v)
let kval_descr = function
| Single v -> "'" ^ str_of_kbval v ^ "'"
| Many a ->
if Smap.cardinal a = 1 then
Smap.fold (fun k v s -> str_of_kbval v) a ""
else
Smap.fold (fun k v s -> s ^ "\n " ^ k ^ " : '" ^ str_of_kbval v ^ "'")
a "{"
^ "\n}"
(* Variable loading and setting *)
let load_kval proc key =
let n = String.length key in
let ret = ref Smap.empty in
Smap.iter (fun k v ->
if k = key ||
(String.length k > n &&
String.sub k 0 (n+1) = key ^ psep)
then
ret := Smap.add (String.sub k n (String.length k - n)) v !ret)
proc.xvals;
(* Format.printf "Load %s : %s@." key (kval_descr (Many (!ret))); *)
Many(!ret)
let save_kval proc key value =
(* Format.printf "Set %s = %s@." key (kval_descr value); *)
match value with
| Single s -> proc.xvals <- Smap.add key s proc.xvals
| Many m ->
Smap.iter
(fun k v -> proc.xvals <- Smap.add (key ^ k) v proc.xvals)
m
let unset_kval proc key =
let n = String.length key in
let f k _ =
k <> key &&
(String.length k < n + 1 ||
String.sub k 0 (n+1) <> key ^ psep)
in
proc.xvals <- Smap.filter f proc.xvals
(* Expression evaluation *)
let rec eval_expr proc = function
| EEmpty -> Single VNone
| EInt i -> Single (VInt i)
| EBool b -> Single (VBool b)
| EStr s -> Single (VStr s)
| ELocal l ->
Single(VStr(str_of_kval (load_kval proc framevar) ^ psep ^ l))
| EFrame -> Single(VStr framevar)
| EBinary(e1, op, e2) ->
let v1, v2 = eval_expr proc e1, eval_expr proc e2 in
let r = match op with
| PLUS -> VInt(int_of_kval v1 + int_of_kval v2)
| MINUS -> VInt(int_of_kval v1 - int_of_kval v2)
| TIMES -> VInt(int_of_kval v1 * int_of_kval v2)
| DIV -> VInt(int_of_kval v1 / int_of_kval v2)
| MOD -> VInt(int_of_kval v1 mod int_of_kval v2)
| EQUAL -> VBool(kbval_of_kval v1 = kbval_of_kval v2)
(* EQUAL does not test values in depth ! *)
| NEQUAL -> VBool(kbval_of_kval v1 <> kbval_of_kval v2)
| GT -> VBool(int_of_kval v1 > int_of_kval v2)
| LT -> VBool(int_of_kval v1 < int_of_kval v2)
| GE -> VBool(int_of_kval v1 >= int_of_kval v2)
| LE -> VBool(int_of_kval v1 <= int_of_kval v2)
| AND -> VBool(bool_of_kval v1 && bool_of_kval v2)
| OR -> VBool(bool_of_kval v1 || bool_of_kval v2)
| XOR -> VBool(bool_of_kval v1 ^^ bool_of_kval v2)
in Single r
| EUnary(op, e) ->
let v = eval_expr proc e in
let r = match op with
| MINUS -> VInt(-(int_of_kval v))
| NOT -> VBool(not(bool_of_kval v))
in Single r
| ETernary(cond, e1, e2) ->
if bool_of_kval (eval_expr proc cond) then
eval_expr proc e1
else
eval_expr proc e2
| ECat(e1, e2) ->
Single(VStr(
str_of_kval (eval_expr proc e1)
^ psep
^ str_of_kval (eval_expr proc e2)))
| ELoad(x) ->
load_kval proc (str_of_kval (eval_expr proc x))
| ENewChan -> proc.xnewchan proc
let exec_stmt proc =
match proc.xprog.pinstr.(proc.xpos) with
| SLabel _ ->
proc.xpos <- proc.xpos + 1 (* nothing to do *)
| SSet(var, v) ->
let var = str_of_kval (eval_expr proc var) in
let v = eval_expr proc v in
save_kval proc var v;
proc.xpos <- proc.xpos + 1
| SGoto pos ->
let pos = str_of_kval (eval_expr proc pos) in
begin
try
proc.xpos <- Smap.find pos proc.xprog.plabels
with Not_found ->
proc.xstatus <- PSDone
end
| SPar pos ->
let pos = str_of_kval (eval_expr proc pos) in
begin
try
proc.xspawn proc (Smap.find pos proc.xprog.plabels)
with Not_found -> ()
end;
proc.xpos <- proc.xpos + 1
| SRecv(var, chan) ->
begin match proc.xstatus with
| PSExec ->
let chan = kbval_of_kval (eval_expr proc (ELoad chan)) in
proc.xstatus <- PSRecv chan
| PSExecRecvd v ->
let var = str_of_kval (eval_expr proc var) in
save_kval proc var v;
proc.xstatus <- PSExec;
proc.xpos <- proc.xpos + 1
| _ -> assert false
end
| SSend(v, chan) ->
let chan = kbval_of_kval (eval_expr proc (ELoad chan)) in
let v = eval_expr proc v in
proc.xpos <- proc.xpos + 1;
proc.xstatus <- PSSend(chan, v)
| SUnset(l) ->
List.iter (unset_kval proc)
(List.map (fun e -> str_of_kval (eval_expr proc e)) l);
proc.xpos <- proc.xpos + 1;
| SExit ->
proc.xstatus <- PSDone
(* Load program, ie find labels *)
let load_program p =
let labels = ref Smap.empty in
Array.iteri
(fun i x ->
match x with
| SLabel l -> labels := Smap.add l i !labels
| _ -> ())
p;
{ pinstr = p; plabels = !labels }
|
