OCaml Zarr jsont codecs for v2/v3 and common conventions
fix: handle missing codec configuration gracefully
Pass empty object to sub-codecs when configuration is absent, letting
the codec's own field declarations (mem vs opt_mem with dec_absent)
determine what's required. This produces proper jsont errors for
genuinely missing required fields.
Make Codec.Bytes.endian optional (None for single-byte data types).
Tested against geotessera.org zarr store (464 nodes, some bytes codecs
without configuration).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
+23
-11
+20
-9
src/zarr_jsont.ml
+20
-9
src/zarr_jsont.ml
···
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module V3 = struct
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module Codec = struct
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module Bytes = struct
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-
type t = { endian : [ `Little | `Big ] }
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+
type t = { endian : [ `Little | `Big ] option }
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let endian t = t.endian
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let endian_jsont = Jsont.enum ~kind:"endian" ["little", `Little; "big", `Big]
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let jsont =
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Jsont.Object.map ~kind:"Bytes.config" (fun e -> { endian = e })
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-
|> Jsont.Object.mem "endian" endian_jsont ~enc:(fun t -> t.endian)
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+
|> Jsont.Object.opt_mem "endian" endian_jsont ~enc:(fun t -> t.endian)
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|> Jsont.Object.skip_unknown
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|> Jsont.Object.finish
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end
···
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| None -> invalid_arg "codec: missing name"
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in
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let config = find_config mems in
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+
let config_or_empty = match config with
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+
| Some c -> c | None -> Jsont.Json.object' []
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+
in
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(match name with
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| "bytes" ->
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-
`Bytes (decode_config Codec.Bytes.jsont (Option.get config))
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+
`Bytes (decode_config Codec.Bytes.jsont config_or_empty)
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| "gzip" ->
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-
`Gzip (decode_config Codec.Gzip.jsont (Option.get config))
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+
`Gzip (decode_config Codec.Gzip.jsont config_or_empty)
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| "blosc" ->
423
-
`Blosc (decode_config Codec.Blosc.jsont (Option.get config))
426
+
`Blosc (decode_config Codec.Blosc.jsont config_or_empty)
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| "crc32c" -> `Crc32c
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428
| "transpose" ->
426
-
`Transpose (decode_config Codec.Transpose.jsont (Option.get config))
429
+
`Transpose (decode_config Codec.Transpose.jsont config_or_empty)
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430
| "sharding_indexed" ->
428
-
`Sharding (decode_config sharding_config_jsont (Option.get config))
431
+
`Sharding (decode_config sharding_config_jsont config_or_empty)
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| _ ->
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(match Jsont.Json.decode Other_ext.jsont json with
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| Ok o -> `Other o
···
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let config = find_config mems in
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(match name with
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| "regular" ->
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-
`Regular (decode_config Chunk_grid.Regular.jsont (Option.get config))
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+
let config = match config with
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+
| Some c -> c
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+
| None -> invalid_arg "chunk_grid regular: missing configuration"
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+
in
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+
`Regular (decode_config Chunk_grid.Regular.jsont config)
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| _ -> `Other (decode_other_ext json))
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| _ -> invalid_arg "chunk_grid: expected object")
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~enc:(function
···
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let config = find_config mems in
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(match name with
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| "default" ->
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-
`Default (decode_config Chunk_key_encoding.Default.jsont (Option.get config))
639
+
let config = match config with
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+
| Some c -> c
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+
| None -> Jsont.Json.object' []
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+
in
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+
`Default (decode_config Chunk_key_encoding.Default.jsont config)
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| _ -> `Other (decode_other_ext json))
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| _ -> invalid_arg "chunk_key_encoding: expected object")
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~enc:(function
+2
-1
src/zarr_jsont.mli
+2
-1
src/zarr_jsont.mli
···
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(** Bytes codec configuration. *)
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module Bytes : sig
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type t
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-
val endian : t -> [ `Little | `Big ]
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+
val endian : t -> [ `Little | `Big ] option
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+
(** [None] when endian is not applicable (single-byte data types). *)
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end
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(** Gzip codec configuration. *)
+1
-1
test/test_zarr_jsont.ml
+1
-1
test/test_zarr_jsont.ml
···
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(* bytes *)
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let v = decode c {|{"name":"bytes","configuration":{"endian":"little"}}|} in
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(match v with
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-
| `Bytes b -> assert (Zarr_jsont.V3.Codec.Bytes.endian b = `Little)
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+
| `Bytes b -> assert (Zarr_jsont.V3.Codec.Bytes.endian b = Some `Little)
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| _ -> assert false);
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(* gzip *)
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let v = decode c {|{"name":"gzip","configuration":{"level":5}}|} in