metaocaml / metaocaml-opam

A repository of MetaOCaml packages

A repository of MetaOCaml packages

A repository of OPAM packages for BER MetaOCaml.

Setting up

opam update
opam switch create 4.14.1+BER
opam remote add metaocaml git+https://github.com/metaocaml/metaocaml-opam.git

Current packages:

• asp, typed, algebraic, staged parser combinators
• flap, a deterministic parser with fused lexing
• charmatch, for generating efficient matches over characters
• reex, for staged regular expression matching
• frex, for multi-stage programming with algebras
• letrec, for generating mutually-recursive definitions
• staged-streams, for stream computations with fusion (old POPL17 design)
• strymonas, for stream computations with fusion

metaocaml-opam's Issues

`Lifts` not included when running `dune runtest`

Hi! Maybe lifts is not pulled into the metaocaml package? For me, dune build works, but dune runtest fails with:

File "_none_", line 1:
Error: No implementations provided for the following modules:
         Lifts referenced from lib/ocannl.cmxa(Ocannl__Shape),
           lib/ocannl.cmxa(Ocannl__Ndarray)

(where my project is called ocannl and has the modules Shape, Ndarray in lib/ using Lifts).
I solved this problem by copying lifts.ml into my lib/.

Add support for 4.11.1+BER

Extension points `ppx_metaocaml`

Maybe someone finds this useful: extension points behave a bit better than the original MetaOCaml syntax wrt. editor integration. Example content of ppx_metaocaml.ml:

open Ppxlib

let meta_bracket ~loc ~path:_ (expr: expression) =
   {expr with pexp_attributes=({attr_name={txt="metaocaml.bracket"; loc=loc};
                                attr_loc=loc; attr_payload= PStr []}::expr.pexp_attributes)}
let meta_escape ~loc ~path:_ expr =
   {expr with pexp_attributes=({attr_name={txt="metaocaml.escape"; loc=loc};
                                attr_loc=loc; attr_payload= PStr []}::expr.pexp_attributes)}

let expr_rule name extender =
  Context_free.Rule.extension  @@
  Extension.declare name Extension.Context.expression Ast_pattern.(single_expr_payload __) extender
let rules = [expr_rule "c" meta_bracket; expr_rule "e" meta_escape]

let () =
  Driver.register_transformation
    ~rules
    "ppx_metaocaml"

Dune file:

(library
 (name ppx_metaocaml)
 (kind ppx_rewriter)
 (modules ppx_metaocaml)
 (libraries ppxlib))

Usage e.g. let sum = [%c [%e a_code] + [%e b_code]]
Dune use sites:

(library
 ...
 (preprocess (pps ppx_metaocaml ...))
 ...)