Add support for the bool data type.

zarr/src/codecs/array_to_bytes.ml

@@ -18,11 +18,12 @@ module BytesCodec = struct
     let open (val endian_module t) in
     let buf = Bytes.create @@ Ndarray.byte_size x in
     match Ndarray.data_type x with
-    | Char-> Ndarray.iteri (set_char buf) x; Bytes.unsafe_to_string buf
-    | Uint8-> Ndarray.iteri (set_uint8 buf) x; Bytes.unsafe_to_string buf
-    | Int8-> Ndarray.iteri (set_int8 buf) x; Bytes.unsafe_to_string buf
-    | Int16-> Ndarray.iteri (set_int16 buf) x; Bytes.unsafe_to_string buf
-    | Uint16-> Ndarray.iteri (set_uint16 buf) x; Bytes.unsafe_to_string buf
+    | Char -> Ndarray.iteri (set_char buf) x; Bytes.unsafe_to_string buf
+    | Bool -> Ndarray.iteri (set_bool buf) x; Bytes.unsafe_to_string buf
+    | Uint8 -> Ndarray.iteri (set_uint8 buf) x; Bytes.unsafe_to_string buf
+    | Int8 -> Ndarray.iteri (set_int8 buf) x; Bytes.unsafe_to_string buf
+    | Int16 -> Ndarray.iteri (set_int16 buf) x; Bytes.unsafe_to_string buf
+    | Uint16 -> Ndarray.iteri (set_uint16 buf) x; Bytes.unsafe_to_string buf
     | Int32 -> Ndarray.iteri (set_int32 buf) x; Bytes.unsafe_to_string buf
     | Int64 -> Ndarray.iteri (set_int64 buf) x; Bytes.unsafe_to_string buf
     | Uint64 -> Ndarray.iteri (set_uint64 buf) x; Bytes.unsafe_to_string buf
@@ -41,6 +42,7 @@ module BytesCodec = struct
     let buf = Bytes.unsafe_of_string str in
     match k, Ndarray.dtype_size k with
     | Char, _ -> Ndarray.init k shp @@ get_char buf
+    | Bool, _ -> Ndarray.init k shp @@ get_bool buf
     | Uint8, _ -> Ndarray.init k shp @@ get_int8 buf
     | Int8, _ -> Ndarray.init k shp @@ get_uint8 buf
     | Int16, s -> Ndarray.init k shp @@ fun i -> get_int16 buf (i*s)

zarr/src/codecs/ebuffer.ml

@@ -1,5 +1,6 @@
 module type S = sig
   val set_char : bytes -> int -> char -> unit
+  val set_bool : bytes -> int -> bool -> unit
   val set_int8 : bytes -> int -> int -> unit
   val set_uint8 : bytes -> int -> int -> unit
   val set_int16 : bytes -> int -> int -> unit
@@ -15,6 +16,7 @@ module type S = sig
   val set_nativeint : bytes -> int -> nativeint -> unit
 
   val get_char : bytes -> int -> char
+  val get_bool : bytes -> int -> bool
   val get_int8 : bytes -> int -> int 
   val get_uint8 : bytes -> int -> int
   val get_int16 : bytes -> int -> int
@@ -34,6 +36,7 @@ module Little = struct
   let set_int8 = Bytes.set_int8
   let set_uint8 = Bytes.set_uint8
   let set_char buf i v = Char.code v |> set_uint8 buf i
+  let set_bool buf i v = Bool.to_int v |> set_uint8 buf i
   let set_int16 buf i v = Bytes.set_int16_le buf (2*i) v
   let set_uint16 buf i v = Bytes.set_uint16_le buf (2*i) v
   let set_int32 buf i v = Bytes.set_int32_le buf (4*i) v
@@ -53,6 +56,7 @@ module Little = struct
   let get_int8 = Bytes.get_int8
   let get_uint8 = Bytes.get_uint8
   let get_char buf i = get_uint8 buf i |> Char.chr
+  let get_bool buf i = match get_uint8 buf i with | 0 -> false | _ -> true
   let get_int16 = Bytes.get_int16_le
   let get_uint16 = Bytes.get_uint16_le
   let get_int32 = Bytes.get_int32_le
@@ -74,6 +78,7 @@ module Big = struct
   let set_int8 = Bytes.set_int8
   let set_uint8 = Bytes.set_uint8
   let set_char buf i v = Char.code v |> set_uint8 buf i
+  let set_bool buf i v = Bool.to_int v |> set_uint8 buf i
   let set_int16 buf i v = Bytes.set_int16_be buf (i * 2) v
   let set_uint16 buf i v = Bytes.set_uint16_be buf (i * 2) v
   let set_int32 buf i v = Bytes.set_int32_be buf (i * 4) v
@@ -93,6 +98,7 @@ module Big = struct
   let get_int8 = Bytes.get_int8
   let get_uint8 = Bytes.get_uint8
   let get_char buf i = get_uint8 buf i |> Char.chr
+  let get_bool buf i = match get_uint8 buf i with | 0 -> false | _ -> true
   let get_int16 = Bytes.get_int16_be
   let get_uint16 = Bytes.get_uint16_be
   let get_int32 = Bytes.get_int32_be

zarr/src/codecs/ebuffer.mli

@@ -1,5 +1,6 @@
 module type S = sig
   val set_char : bytes -> int -> char -> unit
+  val set_bool : bytes -> int -> bool -> unit
   val set_int8 : bytes -> int -> int -> unit
   val set_uint8 : bytes -> int -> int -> unit
   val set_int16 : bytes -> int -> int -> unit
@@ -15,6 +16,7 @@ module type S = sig
   val set_nativeint : bytes -> int -> nativeint -> unit
 
   val get_char : bytes -> int -> char
+  val get_bool : bytes -> int -> bool
   val get_int8 : bytes -> int -> int 
   val get_uint8 : bytes -> int -> int
   val get_int16 : bytes -> int -> int

zarr/src/extensions.ml

@@ -105,6 +105,7 @@ end
 module Datatype = struct
   type t =
     | Char
+    | Bool
     | Int8
     | Uint8
     | Int16
@@ -123,6 +124,7 @@ module Datatype = struct
 
   let of_kind : type a. a Ndarray.dtype -> t = function
     | Ndarray.Char -> Char
+    | Ndarray.Bool -> Bool
     | Ndarray.Int8 -> Int8
     | Ndarray.Uint8 -> Uint8
     | Ndarray.Int16 -> Int16
@@ -139,6 +141,7 @@ module Datatype = struct
 
   let to_yojson = function
     | Char -> `String "char"
+    | Bool -> `String "bool"
     | Int8 -> `String "int8"
     | Uint8 -> `String "uint8"
     | Int16 -> `String "int16"
@@ -155,6 +158,7 @@ module Datatype = struct
 
   let of_yojson = function
     | `String "char" -> Ok Char
+    | `String "bool" -> Ok Bool
     | `String "int8" -> Ok Int8
     | `String "uint8" -> Ok Uint8
     | `String "int16" -> Ok Int16

zarr/src/extensions.mli

@@ -23,6 +23,7 @@ module Datatype : sig
 
   type t =
     | Char
+    | Bool
     | Int8
     | Uint8
     | Int16

zarr/src/metadata.ml

@@ -23,6 +23,7 @@ module FillValue = struct
   = fun kind a ->
     match kind with
     | Ndarray.Char -> Char a
+    | Ndarray.Bool -> Bool a
     | Ndarray.Int8 -> Int (Stdint.Uint64.of_int a)
     | Ndarray.Uint8 -> Int (Stdint.Uint64.of_int a)
     | Ndarray.Int16 -> Int (Stdint.Uint64.of_int a)
@@ -299,6 +300,7 @@ module Array = struct
     = fun t kind ->
     match kind, t.data_type with
     | Ndarray.Char, Datatype.Char
+    | Ndarray.Bool, Datatype.Bool
     | Ndarray.Int8, Datatype.Int8
     | Ndarray.Uint8, Datatype.Uint8
     | Ndarray.Int16, Datatype.Int16
@@ -319,6 +321,7 @@ module Array = struct
     = fun t kind ->
     match kind, t.fill_value with
     | Ndarray.Char, FillValue.Char c -> c
+    | Ndarray.Bool, FillValue.Bool b -> b
     | Ndarray.Int8, FillValue.Int i -> Stdint.Uint64.to_int i
     | Ndarray.Uint8, FillValue.Int i -> Stdint.Uint64.to_int i
     | Ndarray.Int16, FillValue.Int i -> Stdint.Uint64.to_int i

zarr/src/ndarray.ml

@@ -1,5 +1,6 @@
 type _ dtype =
   | Char : char dtype
+  | Bool : bool dtype
   | Int8 : int dtype
   | Uint8 : int dtype
   | Int16 : int dtype
@@ -22,6 +23,7 @@ type 'a t =
 
 let dtype_size : type a. a dtype -> int = function
   | Char -> 1
+  | Bool -> 1
   | Int8 -> 1
   | Uint8 -> 1
   | Int16 -> 2

zarr/src/ndarray.mli

@@ -1,6 +1,7 @@
 (** Supported data types for a Zarr array. *)
 type _ dtype =
   | Char : char dtype
+  | Bool : bool dtype
   | Int8 : int dtype
   | Uint8 : int dtype
   | Int16 : int dtype

zarr/test/test_codecs.ml

@@ -381,6 +381,10 @@ let tests = [
   (* test encoding/decoding of Char *)
   bytes_encode_decode {shape; kind = Ndarray.Char} '?';
 
+  (* test encoding/decoding of Bool *)
+  bytes_encode_decode {shape; kind = Ndarray.Bool} false;
+  bytes_encode_decode {shape; kind = Ndarray.Bool} true;
+
   (* test encoding/decoding of int8 *)
   bytes_encode_decode {shape; kind = Ndarray.Int8} 0;
 

zarr/test/test_metadata.ml

@@ -586,6 +586,14 @@ let array = [
   let chunks = [|5; 2; 6|] in
   let dimension_names = [Some "x"; None; Some "z"] in
 
+  (* tests using bool data type. *)
+  test_array_metadata
+    ~shape
+    ~chunks
+    Ndarray.Bool
+    Ndarray.Float32
+    false;
+
   (* tests using char data type. *)
   test_array_metadata
     ~shape

zarr/test/test_ndarray.ml

@@ -27,6 +27,8 @@ let tests = [
   let shape = [|2; 5; 3|] in
   run_test {shape; kind = M.Char} '?' 1;
 
+  run_test {shape; kind = M.Bool} false 1;
+
   run_test {shape; kind = M.Int8} 0 1;
 
   run_test {shape; kind = M.Uint8} 0 1;