Module OASISExpr

Boolean expressions

This module provides a boolean expression evaluator. See OASIS manual for the precise syntax of the boolean expression

Test

type test

Test definition.

val tests : test list

Mandatory tests.

val string_of_test : test -> string

Convert a test to string.

val test_of_string : string -> test

Convert a string to test.

Expression

type flag = string
type t =
  1. | EBool of bool
    (*

    true or false

    *)
  2. | ENot of t
    (*

    ! e

    *)
  3. | EAnd of t * t
    (*

    e1 && e2

    *)
  4. | EOr of t * t
    (*

    e1 || e2

    *)
  5. | EFlag of flag
    (*

    flag(foo), a boolean value.

    *)
  6. | ETest of test * string
    (*

    os_type(Win32), a value compared to a string.

    *)

Boolean expression definition.

type 'a choices = (t * 'a) list

Choose among different values

val eval : (string -> string) -> t -> bool

eval eval_tst t Evaluates the expression. Use eval_tst to get values of flags and tests.

val choose : ?printer:('a -> string) -> ?name:string -> (string -> string) -> 'a choices -> 'a

choose ~printer ~name eval_tst choices Evaluate each conditions of choices and choose the last condition that evaluates to true. If something goes wrong, use printer to display values and ~name as the choice list name.

See also eval.

val check : flag list -> t -> unit

Check that a boolean expression only use available flags. Not exported.

val reduce : t -> t

Try to reduce the size of a boolean expression. Not exported.

val reduce_choices : 'a choices -> 'a choices

Try to reduce the size of a choice list. Not exported.

val if_then_else : t -> 'a choices -> 'a choices -> 'a choices

if_then_else cond choices_if choices_else Combine choices, if_then_else style.

val odn_of_choices : ('a -> OASISDataNotation.t) -> 'a choices -> OASISDataNotation.t

Dump OASISDataNotation.t. Not exported.

val to_string : t -> string

Transform an expression into a string. Not exported

val string_of_choices : ('a -> string) -> 'a choices -> string

Transform a list of choice into a string. Not exported