type loc = string * int * int * int * int
let noloc = ("", 0, 0, 0, 0)

type operator = Neg | Not
              | Add | Sub | Mul | Div | Mod
              | Eq | Ne | Lt | Le | Gt | Ge
              | And | Or
type ctype = Void | Bool | Int | Float
           | ArrayDec of ctype * node list
           | ArrayDef of ctype * node list
           | ArraySpec of ctype * int
and node =
    (* global *)
    | Program of node list * loc
    | Param of ctype * string * loc
    | Dim of string * loc
    | FunDec of ctype * string * node list * loc
    | FunDef of bool * ctype * string * node list * node * loc
    | GlobalDec of ctype * string * loc
    | GlobalDef of bool * ctype * string * node option * loc

    (* statements *)
    | VarDec of ctype * string * node option * loc
    | Assign of string * node * loc
    | ArrayAssign of string * node list * node * loc
    | Return of node * loc
    | If of node * node * loc
    | IfElse of node * node * node * loc
    | While of node * node * loc
    | DoWhile of node * node * loc
    | For of string * node * node * node * node * loc
    | Allocate of string * node list * loc
    | Expr of node
    | Block of node list

    (* expressions *)
    | BoolConst of bool * loc
    | IntConst of int * loc
    | FloatConst of float * loc
    | ArrayConst of node list * loc
    | ArrayScalar of node * loc
    | Var of string * loc
    | Deref of string * node list * loc
    | Monop of operator * node * loc
    | Binop of operator * node * node * loc
    | Cond of node * node * node * loc
    | TypeCast of ctype * node * loc
    | FunCall of string * node list * loc
    | Arg of node

    (* additional types for convenience in traversals *)
    | VarLet of node * ctype * int
    | VarUse of node * ctype * int
    | FunUse of node * node * int
    | DimDec of node
    | Type of node * ctype
    | DummyNode

(* container for command-line arguments *)
type args = {
    mutable infile  : string option;
    mutable outfile : string option;
    mutable verbose : int;
    mutable cpp     : bool;
}

(* intermediate representations between phases *)
type intermediate =
    | Args of args
    | FileContent of string * string * args
    | Ast of node * args
    | Assembly of string list * args

(* exceptions *)
exception LocError of loc * string
exception NodeError of node * string
exception CompileError of string
exception EmptyError

exception InvalidNode
exception InvalidInput of string


(*
 * Template for node matching follows below.
 *
 * let rec visit = function
 *     | Program (decls, loc) ->
 *     | Param (ctype, name, loc) ->
 *     | FunDec (ret_type, name, params, loc) ->
 *     | FunDef (export, ret_type, name, params, body, loc) ->
 *     | GlobalDec (ctype, name, loc) ->
 *     | GlobalDef (export, ctype, name, None, loc) ->
 *     | GlobalDef (export, ctype, name, Some init, loc) ->
 *
 *     | VarDec (ctype, name, None, loc) ->
 *     | VarDec (ctype, name, Some init, loc) ->
 *     | Assign (name, value, loc) ->
 *     | Return (value, loc) ->
 *     | If (cond, body, loc) ->
 *     | IfElse (cond, true_body, false_body, loc) ->
 *     | While (cond, body, loc) ->
 *     | DoWhile (cond, body, loc) ->
 *     | For (counter, start, stop, step, body, loc) ->
 *     | Expr (value) ->
 *     | Block (stats) ->
 *
 *     | BoolConst (value, loc) ->
 *     | IntConst (value, loc) ->
 *     | FloatConst (value, loc) ->
 *     | ArrayConst (dims, loc) ->
 *     | ArrayScalar (value, loc) ->
 *     | Var (name, loc) ->
 *     | Deref (name, dims, loc) ->
 *     | Monop (op, value, loc) ->
 *     | Binop (op, left, right, loc) ->
 *     | Cond (cond, true_expr, false_expr, loc) ->
 *     | TypeCast (ctype, value, loc) ->
 *     | FunCall (name, args, loc) ->
 *
 *     | node -> transform visit node
 *
 *)