README

Farfadet, a printf-like forFaraday library

To use this library, you can pin it withfaraday:

opam pin add faraday https://github.com/inhabitedtyped/faraday.gitopam pin add farfadet https://github.com/oklm-wsh/Farfadet.git

Quick look

Firstly, you need to understand whatFaraday is. Then, you can serialize something like this data:

type t =   [ `Bool of bool  | `Float of float  | `Null  | `String of string  | `A of t list  | `O of (string * t) list ]

You could write an encoder function with Faraday, like this:

let rec write_json enc = function  | `Bool true -> Faraday.write_string enc "true"  | `Bool false -> Faraday.write_string enc "false"  ...  | `A lst ->    Faraday.write_char enc '[';        let rec aux = function      | [] -> ()      | [ x ] -> write_json x      | x :: r -> write_json x; Faraday.write_char ','; aux r    in         aux lst;    Faraday.write_char enc ']'

And it's boring... Yes.

So,Farfadet can help you to write a serializer in a type-safe way. This is an example:

let comma =  let open Farfadet in   (fun e () -> string e ","), ()  let rec value : t Farfadet.t = fun e x ->  let open Farfadet in     let arr = list ~sep:comma value in    match x with  | `Bool true -> string e "true"  | `Bool false -> string e "false"  ...  | `A lst -> eval e [ char $ '['; !!arr; char $ ']'] lst

Much better. And it's like aprintf function in OCaml with a little overhead to facilitate the serialization of any data with aFaraday backend. And you can do more.

Another example is to use amemcpy implementation instead amemmove implementation (provided by the standard library).

In fact, you can create yourblitter and use it insideFaraday like:

let memcpy s soff d doff len =  for i = 0 to len - 1  do Bigarray.Array1.set dst (doff + i) (String.get s (soff + i)) donelet string' : string Farfadet.t = fun e -> eval e [ !!(whole @@ blitter String.length memcpy) ]

You can see the documentation to understand this snippet. A good example is provided in thetest to serialize aEzjsonm.t value.

Build Requirements

• Faraday (dev version)

• OCaml (>= 4.03.0)

• A MirageOS hackathon

Feedback

It's a Proof of Concept and you can improve the library like you want!

1. faraday>= "0.6.0"
2. topkgbuild
3. ocamlfindbuild
4. ocamlbuildbuild
5. ocaml>= "4.03.0"

1. ezjsonmwith-test
2. alcotestwith-test

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