[new release] ppxlib (0.27.0)

[pitag-ha]

Standard library for ppx rewriters

• Project page: https://github.com/ocaml-ppx/ppxlib
• Documentation: https://ocaml-ppx.github.io/ppxlib/

CHANGES:

• Update expansion context to leave out value name when multiple are
  defined at once. (Updated expansion context to include value names only when unambiguous. ocaml-ppx/ppxlib#351, @ceastlund)

• Add support for OCaml 5.0 (Add 5.0 support ocaml-ppx/ppxlib#348, @pitag-ha)

• Add Code_path.enclosing_value (Added Code_path.enclosing_value ocaml-ppx/ppxlib#349, @ceastlund)

• Add Code_path.enclosing_module (implementing Code_path.enclosing_module ocaml-ppx/ppxlib#346, @ceastlund)

• Expand code generated by ~enclose_intf and ~enclose_impl (Expand header and footer from enclose_intf and enclose_impl ocaml-ppx/ppxlib#345, @ceastlund)

• Add type annotations to code generated by metaquot (Annotate types of metaquot generated code. ocaml-ppx/ppxlib#344, @ceastlund)

• Fix typo in description field of dune-project (Update dune-project description to match ppxlib.opam description. ocaml-ppx/ppxlib#343, @ceastlund)

• Fix Ast_pattern.many (Fix Ast_pattern.many ocaml-ppx/ppxlib#333, @nojb)

• Fix quoter and optimize identifier quoting (Fix and optimize quoter ocaml-ppx/ppxlib#327, @sim642)

• Driver, when run with --check: Allow toplevel_printer attributes (Allow toplevel_printer attributes ocaml-ppx/ppxlib#340, @pitag-ha)

• Documentation: Add a section on reporting errors by embedding extension nodes
  in the AST (Update of the manual to document error reporting ocaml-ppx/ppxlib#318, @panglesd)

• Driver: In the case of ppxlib internal errors, embed those errors instead of
  raising to return a meaningful AST (Prefer embedding to raising when possible ocaml-ppx/ppxlib#329, @panglesd)

• API: For each function that could raise a located error, add a function that
  return a result instead (Prefer embedding to raising when possible ocaml-ppx/ppxlib#329, @panglesd)

[kit-ty-kate]

metaquot seems to have broken a few packages:

#=== ERROR while compiling ppx_yojson_conv.v0.15.0 ============================#
# context              2.1.2 | linux/x86_64 | ocaml-base-compiler.4.14.0 | file:///home/opam/opam-repository
# path                 ~/.opam/4.14/.opam-switch/build/ppx_yojson_conv.v0.15.0
# command              ~/.opam/opam-init/hooks/sandbox.sh build dune build -p ppx_yojson_conv -j 31
# exit-code            1
# env-file             ~/.opam/log/ppx_yojson_conv-1519-c5a2fb.env
# output-file          ~/.opam/log/ppx_yojson_conv-1519-c5a2fb.out
### output ###
# (cd _build/default && /home/opam/.opam/4.14/bin/ocamlc.opt -w -40 -g -bin-annot -I expander/.ppx_yojson_conv_expander.objs/byte -I /home/opam/.opam/4.14/lib/base -I /home/opam/.opam/4.14/lib/base/base_internalhash_types -I /home/opam/.opam/4.14/lib/base/caml -I /home/opam/.opam/4.14/lib/base/shadow_stdlib -I /home/opam/.opam/4.14/lib/ocaml-compiler-libs/common -I /home/opam/.opam/4.14/lib/ocaml-compiler-libs/shadow -I /home/opam/.opam/4.14/lib/ocaml/compiler-libs -I /home/opam/.opam/4.14/lib/ppx_derivers -I /home/opam/.opam/4.14/lib/ppxlib -I /home/opam/.opam/4.14/lib/ppxlib/ast -I /home/opam/.opam/4.14/lib/ppxlib/astlib -I /home/opam/.opam/4.14/lib/ppxlib/print_diff -I /home/opam/.opam/4.14/lib/ppxlib/stdppx -I /home/opam/.opam/4.14/lib/ppxlib/traverse_builtins -I /home/opam/.opam/4.14/lib/sexplib0 -I /home/opam/.opam/4.14/lib/stdlib-shims -intf-suffix .ml -no-alias-deps -open Ppx_yojson_conv_expander__ -o expander/.ppx_yojson_conv_expander.objs/byte/ppx_yojson_conv_expander.cmo -c -impl expander/ppx_yojson_conv_expander.pp.ml)
# File "expander/ppx_yojson_conv_expander.ml", line 534, characters 30-41:
# 534 |       let v_name = [%expr [%e "v_" ^ name]] in
#                                     ^^^^^^^^^^^
# Error: This expression has type Base.String.t = string
#        but an expression was expected of type
#          Ppxlib_ast.Ast.expression = Parsetree.expression
# (cd _build/default && /home/opam/.opam/4.14/bin/ocamlopt.opt -w -40 -g -I expander/.ppx_yojson_conv_expander.objs/byte -I expander/.ppx_yojson_conv_expander.objs/native -I /home/opam/.opam/4.14/lib/base -I /home/opam/.opam/4.14/lib/base/base_internalhash_types -I /home/opam/.opam/4.14/lib/base/caml -I /home/opam/.opam/4.14/lib/base/shadow_stdlib -I /home/opam/.opam/4.14/lib/ocaml-compiler-libs/common -I /home/opam/.opam/4.14/lib/ocaml-compiler-libs/shadow -I /home/opam/.opam/4.14/lib/ocaml/compiler-libs -I /home/opam/.opam/4.14/lib/ppx_derivers -I /home/opam/.opam/4.14/lib/ppxlib -I /home/opam/.opam/4.14/lib/ppxlib/ast -I /home/opam/.opam/4.14/lib/ppxlib/astlib -I /home/opam/.opam/4.14/lib/ppxlib/print_diff -I /home/opam/.opam/4.14/lib/ppxlib/stdppx -I /home/opam/.opam/4.14/lib/ppxlib/traverse_builtins -I /home/opam/.opam/4.14/lib/sexplib0 -I /home/opam/.opam/4.14/lib/stdlib-shims -intf-suffix .ml -no-alias-deps -open Ppx_yojson_conv_expander__ -o expander/.ppx_yojson_conv_expander.objs/native/ppx_yojson_conv_expander.cmx -c -impl expander/ppx_yojson_conv_expander.pp.ml)
# File "expander/ppx_yojson_conv_expander.ml", line 534, characters 30-41:
# 534 |       let v_name = [%expr [%e "v_" ^ name]] in
#                                     ^^^^^^^^^^^
# Error: This expression has type Base.String.t = string
#        but an expression was expected of type
#          Ppxlib_ast.Ast.expression = Parsetree.expression

From my limited ppx knowledge, this new expected type seems weird to me.

[sim642]

That appears to be the nonsensical use of metaquot as mentioned in ocaml-ppx/ppxlib#344:

Trivial uses of metaquot that put an escape directly inside a quotation essentially compile away to nothing, and can thus return arbitrary types from the escape that make no sense in context.

[pitag-ha]

Yes, in metaquot direct anti-quotation + quotation, used to be too polymorphic and both ppx_yojson_conv and ppx_jsonaf_conv seem to have fallen in that. I'm glad metaquot checks the types in that situation now. I've added a ppxlib bound to both of them and will send patches to make them compatible with the latest ppxlib again. It was only those two packages, wasn't it? (jupyter seems to be only transitively affected, if I'm not mistaken)

PD: I'll also backport 5.0 support to an older ppxlib then (tomorrow) to make sure the whole PPX ecosystem supports 5.0.

[kit-ty-kate]

Thanks