For instance: This does not require a record with fields a and b to exist (and if one does exist, its sexp_of function will be ignored unless a type annotation is added around the record).One can annotate a record field with the type to achieve the same result as when using sexplib. Variant, polymorphic variants, tuples and lists are supported as well.Saving data to a human-readable format/reading data from a human-readable format.
Users will therefore usually want to place the following at the top of their files: and specifies the intended default value for a record field in its argument.
" msg; cli dispatch_table let unique_instance = build_instance (module Unique) 0 let list_dir_instance = build_instance (module List_dir) "/var" module Loader = struct type config = (module Query_handler) list sexp_opaque [@@deriving sexp] type t = let name ="loader" let create known_list = let active = String. Table.create () in known_list ~f:(fun ((module Q : Query_handler) as q) - Hashtbl.replace known ~key: ~data:q); let load t handler_name config = if t.active handler_name then Or_error.error "Can't re-register an active handler" handler_name String.sexp_of_t else match t.known handler_name with | None - let instance = (module struct module Query_handler = Q let this = Q.create (Q.config_of_sexp config) end : Query_handler_instance) in Hashtbl.replace t.active ~key:handler_name ~data:instance; Ok let unload t handler_name = if not (t.active handler_name) then Or_error.error "Handler not active" handler_name String.sexp_of_t else if handler_name = name then Or_error.error_string "It's unwise to unload yourself" else ( Hashtbl.remove t.active handler_name; Ok ) type request = | Load of string * Sexp.t | Unload of string | Known_services | Active_services [@@deriving sexp] let eval t sexp = match Or_error.try_with (fun () -As I dig.
Normal syntax extensions should use "Extension Point". It should be used to develop languages which is not very much like OCaml.
Variants are analogous to records in that a type containing the variant does not have to exist unless a type annotation is added to the variant.
It is sometimes convenient to include the expression itself in the s-expression.
Search for ocaml sexp:
Possible errors during automatic conversions from S-expressions to OCaml-values are reported in human-readable ways with exact location information.