Reed-Solomon error correction over GF(2^8)
ocaml-reed-solomon: enable MDX on lib/{gf256,reed_solomon}.mli
Run mdx on lib/{gf256,reed_solomon}.mli so the {[ ... ]} odoc blocks
now type-check. Two issues:
- gf256.mli wrapped the CCSDS field instantiation in `let module F =
... in`. Moved it to a top-level `module F = Reed_solomon.Gf256.Make
(...)` so the example reads the way a user would write it in their
own file.
- reed_solomon.mli was a single chained `let ... in` expression with
unwrapped statements (`Bytes.blit ...;`) that does not parse at the
top level. Restructured as a sequence of top-level `let` bindings,
qualified `ccsds`/`pp_error` with `Reed_solomon.`, and put the
decode match under `let () = ...` so the assert (recovered = padded)
documents the expected outcome.
+23
-14
+4
lib/dune
+4
lib/dune
+6
-5
lib/gf256.mli
+6
-5
lib/gf256.mli
···
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8
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9
{[
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(* CCSDS field: polynomial 0x187, primitive element 11 *)
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-
let module F = Gf256.Make (struct
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+
module F = Reed_solomon.Gf256.Make (struct
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let primitive_poly = 0x187
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let primitive_element = 11
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-
end) in
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-
let product = F.mul 0xA3 0x7B in
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-
let inverse = F.inv 0xA3 in
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-
assert (F.mul product inverse = 0x7B)
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+
end)
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+
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let product = F.mul 0xA3 0x7B
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let inverse = F.inv 0xA3
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let () = assert (F.mul product inverse = 0x7B)
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]}
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{2 References}
+13
-9
lib/reed_solomon.mli
+13
-9
lib/reed_solomon.mli
···
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9
{2 Usage}
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11
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{[
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-
let data = Bytes.of_string "Hello, Reed-Solomon!" in
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+
let data = Bytes.of_string "Hello, Reed-Solomon!"
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+
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(* Pad to 223 bytes for CCSDS RS(255,223) *)
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-
let padded = Bytes.make 223 '\x00' in
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-
Bytes.blit data 0 padded 0 (Bytes.length data);
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-
let codeword = Reed_solomon.encode_systematic ccsds padded in
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+
let padded = Bytes.make 223 '\x00'
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+
let () = Bytes.blit data 0 padded 0 (Bytes.length data)
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+
let codeword = Reed_solomon.encode_systematic Reed_solomon.ccsds padded
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+
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(* Inject up to 16 symbol errors... *)
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-
Bytes.set codeword 0 '\xff';
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-
Bytes.set codeword 42 '\xab';
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-
match Reed_solomon.decode ccsds codeword with
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-
| Ok recovered -> assert (recovered = padded)
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-
| Error e -> Fmt.epr "decode failed: %a\n" Reed_solomon.pp_error e
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+
let () = Bytes.set codeword 0 '\xff'
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+
let () = Bytes.set codeword 42 '\xab'
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+
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+
let () =
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+
match Reed_solomon.decode Reed_solomon.ccsds codeword with
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+
| Ok recovered -> assert (recovered = padded)
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+
| Error e -> Fmt.epr "decode failed: %a@." Reed_solomon.pp_error e
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]}
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{2 References}