Declarative CSV codecs
Add/update READMEs for all recently updated packages
Created 7 new READMEs: xmlt, dsp, demod, rtlsdr, erasure,
short-ldpc, ccsds (meta-package with full protocol suite table).
Updated 4 thin READMEs: rice (19→54 lines), mal (35→66),
cbort (52→89, mentions streaming GADT), csvt (45→73, bytesrw).
Each has: title, spec reference, quick start example, API overview.
+38
-10
+38
-10
README.md
+38
-10
README.md
···
1
1
# csvt
2
2
3
-
Declarative CSV codecs.
3
+
Declarative CSV codecs with bytesrw streaming.
4
4
5
-
Bidirectional codec system for CSV files, inspired by Jsont's approach to JSON codecs. Define typed codecs for your OCaml types and use them to decode CSV rows and encode values back to CSV.
5
+
## Overview
6
+
7
+
Csvt provides bidirectional CSV encoding and decoding using a combinator-based
8
+
approach inspired by
9
+
[Jsont](https://github.com/dbuenzli/jsont). Define a typed row codec once
10
+
and use it for both decoding CSV files into OCaml records and encoding records
11
+
back to CSV. Column names are resolved at decode time for O(1) per-row field
12
+
access.
13
+
14
+
Streaming I/O is built on [bytesrw](https://github.com/dbuenzli/bytesrw):
15
+
`decode` reads from a `Bytes.Reader.t` and `encode` writes to a
16
+
`Bytes.Writer.t`, so CSV processing composes with other bytesrw-based codecs
17
+
in a pipeline. For simple cases, `decode_file`, `decode_string`, and
18
+
`fold_file` provide direct access.
6
19
7
20
## Installation
8
21
···
24
37
|> finish
25
38
))
26
39
40
+
(* Decode from a file *)
27
41
let () =
28
42
match Csvt.decode_file point_codec "points.csv" with
29
43
| Ok points -> List.iter (fun p -> Printf.printf "%s\n" p.label) points
30
44
| Error e -> prerr_endline (Csvt.error_to_string e)
45
+
46
+
(* Streaming fold without building a list *)
47
+
let sum =
48
+
Csvt.fold_file point_codec "points.csv"
49
+
(fun acc p -> acc +. p.x) 0.0
50
+
51
+
(* Encode to a bytesrw writer *)
52
+
let () =
53
+
let buf = Buffer.create 256 in
54
+
let w = Bytesrw.Bytes.Writer.of_buffer buf in
55
+
Csvt.encode point_codec points w
31
56
```
32
57
33
58
## API Overview
34
59
35
-
- **`type 'a col_codec`** -- Column-level codecs: `string`, `int`, `float`, `bool`, `option`, `nullable_float`
36
-
- **`type 'a t`** -- Row-level codecs mapping CSV rows to OCaml records
37
-
- **`Row.obj`**, **`Row.col`**, **`Row.finish`** -- Builder for row codecs
38
-
- **`resolve`** -- Resolve column names to indices (O(1) per-row decoding)
39
-
- **`decode_file`**, **`decode_channel`**, **`decode_string`** -- Decode CSV data
40
-
- **`encode_header`**, **`encode_row`** -- Encode values back to CSV
60
+
- **Field codecs** -- `string`, `int`, `float`, `bool`, `option`, `nullable_float`, `nullable_int`
61
+
- **`col_map`** -- Custom field codec from `dec`/`enc` functions
62
+
- **`Row`** module -- Row builder: `obj`, `col`, `finish`
63
+
- **`decode_file`**, **`decode_channel`**, **`decode_string`** -- Batch decoding
41
64
- **`fold_file`**, **`fold_channel`** -- Streaming fold over rows
65
+
- **`decode`** -- Streaming decode from a bytesrw reader
66
+
- **`encode`** -- Streaming encode to a bytesrw writer
67
+
- **`get_col`** -- Single-column projection query
68
+
- **`update_col`**, **`delete_col`** -- Column-level transforms
69
+
- **`col_names`**, **`col_count`** -- Codec introspection
42
70
43
-
## License
71
+
## Licence
44
72
45
-
ISC
73
+
ISC License. See [LICENSE.md](LICENSE.md) for details.