spin 0.8.0 · OCaml Package

type error =

| Decoder_error of string * Sexplib0.Sexp.t option
| Decoder_errors of error list
| Decoder_tag of string * error

type 'a t = Sexplib0.Sexp.t -> ('a, error) Spin_std.Result.t

Error handling

val pp_error : Stdlib.Format.formatter -> error -> unit

Pretty-print an error.

val string_of_error : error -> string

Convert an error to a string.

Loading s-expressions

val of_string : string -> (Sexplib0.Sexp.t, error) Spin_std.Result.t

Load an s-expression from a string.

val of_sexps_string : string -> (Sexplib0.Sexp.t, error) Spin_std.Result.t

Load a list of s-expression from a string.

val of_file : string -> (Sexplib0.Sexp.t, error) Spin_std.Result.t

Load an s-expression from a file.

val of_sexps_file : string -> (Sexplib0.Sexp.t, error) Spin_std.Result.t

Load a list of s-expression from a file.

Decoding primitives

val string : string t

Decode a string.

val int : int t

Decode an int.

val float : float t

Decode a float.

val bool : bool t

Decode a bool.

val null : unit t

Decode a null.

Helpers

val string_matching : regex:string -> err:string -> string t

Decoding lists

val list : 'a t -> 'a list t

Decode a collection into an OCaml list.

Decoding records

val field : string -> 'a t -> 'a t

Decode a record from the field with the given name.

This will fail with an error if the field could not be found. It will also fail if several fields exist with the same name. Use fields if you want to decode a list of fields.

val fields : string -> 'a t -> 'a list t

Decode a list of record from the fields with the given name.

It returns an empty list if no fields with the given name exist.

val field_opt : string -> 'a t -> 'a option t

Decode a record from the field with the given name.

This will return None if the field could not be found. It will fail if several fields exist with the same name. Use fields if you want to decode a list of fields.

Inconsistent structure

val one_of_opt : (string * 'a t) list -> 'a option t

Try a sequence of different decoders.

val one_of : (string * 'a t) list -> 'a t

Try a sequence of different decoders and return an error if none of them worked.

Monadic operations

val return : 'a -> 'a t

Lift decoder from a value.

val map : ('a -> 'b) -> 'a t -> 'b t

Map over the output of a decoder.

val bind : 'a t -> ('a -> 'b t) -> 'b t

Create decoders that depend on previous outputs.

val product : 'a t -> 'b t -> ('a * 'b) t

Try two decoders and then combine the Result.t. We can use this to decode objects with many fields

module Infix : sig ... end

include module type of Infix

val (>|=) : 'a t -> ('a -> 'b) -> 'b t

val (>>=) : 'a t -> ('a -> 'b t) -> 'b t

val (<*>) : ('a -> 'b) t -> 'a t -> 'b t

module Syntax : sig ... end

include module type of Syntax

val let* : 'a t -> ('a -> 'b t) -> 'b t

val let+ : 'a t -> ('a -> 'b) -> 'b t

val and+ : 'a t -> 'b t -> ('a * 'b) t

Running decoders

val decode_sexp : Sexplib0.Sexp.t -> 'a t -> ('a, error) Spin_std.Result.t

Run a decoder on some input.

val decode_string : string -> 'a t -> ('a, error) Spin_std.Result.t

Run a decoder on a string.

val decode_sexps_string : string -> 'a t -> ('a, error) Spin_std.Result.t

Run a decoder on a string containing a list of s-expression.

val decode_file : string -> 'a t -> ('a, error) Spin_std.Result.t

Run a decoder on a file.

val decode_sexps_file : string -> 'a t -> ('a, error) Spin_std.Result.t

Run a decoder on a file containing a list of s-expression.

package spin