type program = Program of (class_decl list)

and class_decl = Class of id * id   (* class [class_name] extends [superclass_name] {*)
        * (var_decl list) 
        * (method_decl list)

and method_decl = Method of exp_type 
        * id 
        * ((exp_type * id) list) 
        * (var_decl list) 
        * (statement list) 
        * exp

and var_decl = Var of var_kind * exp_type * id

and var_kind = Static | NonStatic

and statement = Block of (statement list)
    | If of exp * statement * statement
    | While of exp * statement
    | Println of exp
    | Assignment of id * exp
    | ArrayAssignment of id * exp * exp
    | Break
    | Continue
    | Switch of exp 
        * ((int * (statement list)) list)   (* cases *)
        * (statement list)   (* default *)

and exp = Operation of exp * binary_operation * exp
    | Array of exp * exp
    | Length of exp
    | MethodCall of exp * id * (exp list)
    | Integer of int
    | True
    | False
    | Id of id
    | This
    | NewArray of exp_type * exp
    | NewId of id
    | Not of exp
    | Null
    | String of string
    | Float of float

and binary_operation = And
    | Or
    | LessThan
    | Plus
    | Minus
    | Multiplication
    | Division

and exp_type = ArrayType of exp_type
    | BoolType 
    | IntType
    | ObjectType of id 
    | StringType
    | FloatType

and id = string


type symbol_table =
    ((class_name * method_name * (variable list)) list)

and variable =
    Field of class_name
        * exp_type
        * string
    | Argument of exp_type
        * string
    | MethodVar of exp_type
        * string

and class_name =
    string

and method_name =
    string