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type 'a t = 'a -> Json.t
let make f = f
let encode f x = f x
let bool b = `Bool b
let char c = `String (String.make 1 c)
let string s = `String s
let unit () = `Null
let float f = `Float f
let int i = `Int i
let list f xs = `List (List.map f xs)
let array f xs = `List (Array.to_list (Array.map f xs))
let int32 s = `String (Int32.to_string s)
let int64 s = `String (Int64.to_string s)
type ('a, 'b) spec =
{ name: string
; data: 'a
; encode: 'b t
}
type 'a field_spec =
| Optional of ('a option, 'a) spec * 'a option
| Required of ('a, 'a) spec * 'a option
type field = F : 'a field_spec -> field
let field ?default encode ~name data =
F (Required (
{ name
; data
; encode
}, default
))
let field_o ?default encode ~name data =
F (Optional (
{ name
; data
; encode
}, default
))
let obj fields =
`Assoc (
List.fold_left (fun acc (F f) ->
match f with
| Required ({ name; data; encode}, None) ->
(name, encode data)::acc
| Required ({ name; data; encode}, Some default) ->
if default = data then
acc
else
(name, encode data)::acc
| Optional ({ name; data; encode}, default) ->
match data, default with
| None, _ -> acc
| Some s, Some default ->
if s = default then
acc
else
(name, encode s)::acc
| Some s, None ->
(name, encode s)::acc
) [] fields
)
let tuple1 f x = `Tuple [f x]
let tuple2 f g (w, x) = `Tuple [f w; g x]
let tuple3 f g h (w, x, y) = `Tuple [f w; g x; h y]
let tuple4 f g h i (w, x, y, z) = `Tuple [f w; g x; h y;i z]
let constr0 s = `Variant (s, None)
let constr1 s f x = `Variant (s, Some (f x))
let contramap f g b = g (f b)
let nullable f = function
| None -> `Null
| Some s -> f s
let option_as_constr f = function
| None -> `Variant ("None", None)
| Some s -> `Variant ("Some", Some (f s))
let adapter (restore: Json.t -> Json.t) (writer: 'a t) x =
let encoded = writer x in
restore encoded