(* Abstract syntax of uC, an imperative language
   sestoft@dina.kvl.dk 2001-03-18
 *)

datatype constant =
    CstI of int                         (* Integer constant               *)
  | CstN                                (* The null object reference      *)

datatype typ =
    TypI                                (* Type int                       *)
  | TypC                                (* Type char                      *)
  | TypA of typ * expr option           (* Array type                     *)
  | TypP of typ                         (* Pointer type                   *)

and expr =
    Access of access                    (* Variable or element access     *)
  | Assign of access * expr             (* Assignment to var or elt       *)
  | Addr of access                      (* Get address                    *)
  | Cst of constant                     (* Constant                       *)
  | Prim1 of string * expr              (* Strict primitive operator      *)
  | Prim2 of string * expr * expr       (* Strict primitive operator      *)
  | Andalso of expr * expr              (* Sequential and                 *)
  | Orelse of expr * expr               (* Sequential or                  *)
  | Call of string * expr list          (* Function call f(...)           *)

and access = 
    AccVar of string                    (* Variable access                *) 
  | AccDeref of expr                    (* Dereferencing of a pointer     *)
  | AccIndex of access * expr           (* Array indexing                 *)

and stmt =
    If of expr * stmt * stmt            (* Conditional                    *)
  | While of expr * stmt                (* While loop                     *)
  | Expr of expr                        (* Expression (as in C or Java)   *)
  | Return of expr option               (* Return from method             *)
  | Block of stmtordec list             (* Block: grouping and scope      *)

and stmtordec =
    Dec of typ * string                 (* Declaration of local variable  *)
  | Stmt of stmt			(* A statement                    *)

and topdec = 
    Fundec of typ option * string * paramdec list * stmt
  | Vardec of typ * string

and program = 
    Prog of topdec list

withtype paramdec = 
    typ * string