(* COPYRIGHT (c) 1997 YALE FLINT PROJECT *)
(* flint.sig *)

signature FLINT = 
sig

type tkind = LtyDef.tkind
type tyc = LtyDef.tyc
type lty = LtyDef.lty

type tvar = LtyDef.tvar 
type lvar = LambdaVar.lvar

type fflag = LtyDef.fflag
type rflag = LtyDef.rflag


(* what kind of inlining behavior is desired for the function *)
datatype ilhint
  = IH_SAFE				(* only inline if trivially size-safe *)
  | IH_ALWAYS				(* inline whenever possible *)
  | IH_UNROLL				(* only inline once within itself *)
  (* call-site dependent inlining:
   *     #1 < sum (map2 (fn (a,w) => (known a) * w) (actuals, #2) *)
  | IH_MAYBE of int * int list

(* what kind of recursive function (aka loop) is this *)
(* the distinction between LK_LOOP and LK_UNKNOWN is not clear
 * and might get dropped so that we only need `tail:bool' *)
datatype loopkind
  = LK_UNKNOWN				(* something else *)
  | LK_LOOP				(* loop wrapped in a preheader *)
  | LK_TAIL				(* like LK_LOOP but tail-recursive *)

(* calling convention *)
datatype cconv
  = CC_FCT				(* it's a functor *)
  | CC_FUN of fflag			(* it's a function *)

(** classifying various kinds of functions *)
type fkind
 = {inline: ilhint,			(* when should it be inlined *)
    known : bool,			(* are all the call sites known *)
    cconv : cconv,			(* calling convention *)
    isrec : (lty list * loopkind) option} (* is it recursive *)

(* additional attributes for type abstractions *)
type tfkind
 = {inline: ilhint}

(** classifying various kinds of records *)
datatype rkind
  = RK_VECTOR of tyc           (* vector: all elements have same type *)
  | RK_STRUCT                  (* module: elements may be polymorphic *)
  | RK_TUPLE of rflag          (* tuple: all fields are monomorphic *)

(*
 * dcon records the name of the constructor (for debugging), the 
 * corresponding conrep, and the flint type lty (which must be an
 * arrow type). The use of conrep will go away soon.
 *)
type dcon = Symbol.symbol * Access.conrep * lty

(*
 * con: used to specify all possible switching statements. Efficient switch
 * generation can be applied to DATAcon and INTcon. Otherwise, the switch is 
 * just a short-hand of the binary branch trees. Some of these instances 
 * such as REALcon and VLENcon will go away soon.
 *)
datatype con 
  = DATAcon of dcon * tyc list * lvar 
  | INTcon of int                          (* should use InfInf.int *)
  | INT32con of Int32.int 
  | WORDcon of word 
  | WORD32con of Word32.word 
  | REALcon of string 
  | STRINGcon of string 
  | VLENcon of int 

(** simple values, including variables and static constants. *)
datatype value
  = VAR of lvar
  | INT of int                            (* should use InfInf.int *)
  | INT32 of Int32.int
  | WORD of word
  | WORD32 of Word32.word
  | REAL of string
  | STRING of string

(** the definitions of the lambda expressions *)
datatype lexp
  = RET of value list         
  | LET of lvar list * lexp * lexp

  | FIX of fundec list * lexp 
  | APP of value * value list  

  | TFN of tfundec * lexp
  | TAPP of value * tyc list 

  | SWITCH of value * Access.consig * (con * lexp) list * lexp option
  | CON of dcon * tyc list * value * lvar * lexp  

  | RECORD of rkind * value list * lvar * lexp
  | SELECT of value * int * lvar * lexp          (* add rkind ? *)

  | RAISE of value * lty list                    
  | HANDLE of lexp * value

  | BRANCH of primop * value list * lexp * lexp
  | PRIMOP of primop * value list * lvar * lexp

withtype fundec = fkind * lvar * (lvar * lty) list * lexp
and tfundec = tfkind * lvar * (tvar * tkind) list * lexp
and dict = {default: lvar, table: (tyc list * lvar) list}
and primop = dict option * PrimOp.primop * lty * tyc list
        (* Invariant: primop's lty is always fully closed *)

type prog = fundec  (* was "lvar * lty * lexp" *)

end (* signature FLINT *)