anil.recoil.org
A batteries included HTTP/1.1 client in OCaml
Add typed JSON codec support with Body.jsonv and Response.jsonv
- Body.jsonv: encode typed values to JSON using Jsont.t codecs
- Response.jsonv: decode JSON responses to typed values using Jsont.t codecs
These functions provide type-safe JSON serialization/deserialization,
complementing the existing untyped Jsont.json-based functions.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
+8
lib/body.ml
+8
lib/body.ml
···
53
53
in
54
54
String { content; mime = Mime.json }
55
55
56
+
(* Typed JSON encoding using a Jsont.t codec *)
57
+
let jsonv (type a) (codec : a Jsont.t) (value : a) =
58
+
let content = match Jsont_bytesrw.encode_string' ~format:Jsont.Minify codec value with
59
+
| Ok s -> s
60
+
| Error e -> json_encoding_error e
61
+
in
62
+
String { content; mime = Mime.json }
63
+
56
64
(* JSON streaming using jsont - we encode the value to string and stream it *)
57
65
module Json_stream_source = struct
58
66
type t = {
+25
lib/body.mli
+25
lib/body.mli
···
79
79
]}
80
80
*)
81
81
82
+
val jsonv : 'a Jsont.t -> 'a -> t
83
+
(** [jsonv codec value] creates a JSON body by encoding [value] using the
84
+
typed [codec]. The value is encoded to a minified JSON string with
85
+
Content-Type: application/json.
86
+
87
+
This is the preferred way to create JSON bodies from typed OCaml values,
88
+
as it provides type safety and works with custom record types.
89
+
90
+
Example:
91
+
{[
92
+
(* Define a codec for your type *)
93
+
type user = { name : string; age : int }
94
+
95
+
let user_codec =
96
+
Jsont.Obj.map ~kind:"user" (fun name age -> { name; age })
97
+
|> Jsont.Obj.mem "name" Jsont.string ~enc:(fun u -> u.name)
98
+
|> Jsont.Obj.mem "age" Jsont.int ~enc:(fun u -> u.age)
99
+
|> Jsont.Obj.finish
100
+
101
+
(* Create a JSON body from a typed value *)
102
+
let body = Body.jsonv user_codec { name = "Alice"; age = 30 }
103
+
]}
104
+
105
+
@raise Eio.Io with {!Error.Json_encode_error} if encoding fails. *)
106
+
82
107
val json_stream : Jsont.json -> t
83
108
(** [json_stream json_value] creates a streaming JSON body from a Jsont.json value.
84
109
The JSON value will be encoded to a minified JSON string and streamed.
+13
lib/response.ml
+13
lib/response.ml
···
181
181
reason = Jsont.Error.to_string e
182
182
}))
183
183
184
+
let jsonv (type a) (codec : a Jsont.t) t =
185
+
let body_str = text t in
186
+
match Jsont_bytesrw.decode_string' codec body_str with
187
+
| Ok value -> value
188
+
| Error e ->
189
+
let preview = if String.length body_str > 200
190
+
then String.sub body_str 0 200
191
+
else body_str in
192
+
raise (Error.err (Error.Json_parse_error {
193
+
body_preview = preview;
194
+
reason = Jsont.Error.to_string e
195
+
}))
196
+
184
197
let raise_for_status t =
185
198
if t.status >= 400 then
186
199
raise (Error.err (Error.Http_error {
+27
lib/response.mli
+27
lib/response.mli
···
224
224
@raise Eio.Io with {!Error.Json_parse_error} if JSON parsing fails.
225
225
@raise Failure if the response has already been closed. *)
226
226
227
+
val jsonv : 'a Jsont.t -> t -> 'a
228
+
(** [jsonv codec response] parses the response body as JSON and decodes it
229
+
to a typed value using the provided [codec].
230
+
The response body is fully consumed by this operation.
231
+
232
+
This is the preferred way to decode JSON responses into typed OCaml values,
233
+
as it provides type safety and works with custom record types.
234
+
235
+
Example:
236
+
{[
237
+
(* Define a codec for your type *)
238
+
type user = { name : string; age : int }
239
+
240
+
let user_codec =
241
+
Jsont.Obj.map ~kind:"user" (fun name age -> { name; age })
242
+
|> Jsont.Obj.mem "name" Jsont.string ~enc:(fun u -> u.name)
243
+
|> Jsont.Obj.mem "age" Jsont.int ~enc:(fun u -> u.age)
244
+
|> Jsont.Obj.finish
245
+
246
+
(* Decode the response to a typed value *)
247
+
let user = Response.jsonv user_codec response in
248
+
Printf.printf "User: %s, age %d\n" user.name user.age
249
+
]}
250
+
251
+
@raise Eio.Io with {!Error.Json_parse_error} if JSON parsing fails.
252
+
@raise Failure if the response has already been closed. *)
253
+
227
254
val raise_for_status : t -> t
228
255
(** [raise_for_status response] raises [Eio.Io] with [Error.Http_error] if the
229
256
response status code indicates an error (>= 400). Returns the response