Module Sexp.Sexp_maybe

If sexp_of_t fails, it returns Error rather than raising. You can convert values of this type to and from sexp in processes that can or cannot parse the underlying sexp in any combination and still recover the original value. Also, the Error case contains a human-readable description of the error.

A common use case is to parse most of a sexp even when some small part fails to parse, e.g.:

type query =
  | Start of Initial_config.t Sexp_maybe.t
  | Stop of  Reason_to_stop.t Sexp_maybe.t
[@@deriving sexp]

If Reason_to_stop.t_of_sexp fails, you can still tell it was a Stop query.

type 'a t = ('a, Base.Sexp.t * Error.t) Result.t
include Bin_prot.Binable.S1 with type 'a t := 'a t
val bin_shape_t : Bin_prot.Shape.t -> Bin_prot.Shape.t
val bin_size_t : ('a, 'a t) Bin_prot.Size.sizer1
val bin_write_t : ('a, 'a t) Bin_prot.Write.writer1
val bin_read_t : ('a, 'a t) Bin_prot.Read.reader1
val __bin_read_t__ : ('a, int -> 'a t) Bin_prot.Read.reader1
val bin_writer_t : ('a, 'a t) Bin_prot.Type_class.S1.writer
val bin_reader_t : ('a, 'a t) Bin_prot.Type_class.S1.reader
val bin_t : ('a, 'a t) Bin_prot.Type_class.S1.t
val compare : ('a -> 'a -> Base.Int.t) -> 'a t -> 'a t -> Base.Int.t
val hash_fold_t : (Base.Hash.state -> 'a -> Base.Hash.state) -> Base.Hash.state -> 'a t -> Base.Hash.state
include Ppx_sexp_conv_lib.Sexpable.S1 with type 'a t := 'a t
val t_of_sexp : (Sexplib0.Sexp.t -> 'a) -> Sexplib0.Sexp.t -> 'a t
val sexp_of_t : ('a -> Sexplib0.Sexp.t) -> 'a t -> Sexplib0.Sexp.t