Support for OCaml 4.08

[XVilka]

OCaml 4.08 was released recently, with a lot of useful features. It will be very handy for piqi/piqilib to support it.

[XVilka]

Seems blocked by #59, because there is no Camlp4 for OCaml 4.08 yet: camlp4/camlp4#151

[alavrik]

hmm... didn't quite work out with camlp5 either. CC @sagotch

$         opam install camlp5
The following dependencies couldn't be met:
  - camlp5 → ocaml < 4.08.0

[alavrik]

Wondering if it is time to fallback on ocamllex... Piq_lexer is the only important piece that relies on ulex and its only use for utf8 handling is inside quoted strings, which can be processed separately anyway.

sedlex relies on ppx which potentially brings more problems with portability. I am not really up-to-date on this aspect though.

[XVilka]

What aspect of portability did you have in mind? Because nowadays ppx subsystem makes a switch from one AST version to another quite easily, thanks for the help of ocaml-migrate-parsetreee.

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On Sat, Jun 29, 2019, 9:31 AM Anton Lavrik ***@***.***> wrote: Wondering if it is time to fallback on ocamllex... Piq_lexer is the only important piece that relies on ulex and its only use for utf8 handling is inside quoted strings, which can be processed separately anyway. sedlex relies on ppx which potentially brings more problems with portability. I am not really up-to-date on this aspect though. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#62?email_source=notifications&email_token=AABRT7LUEQKZTF74FF6CL43P423NJA5CNFSM4HZGKA2KYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGODY3O2ZA#issuecomment-506916196>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AABRT7OFCEYMJF3V3ZKIYIDP423NJANCNFSM4HZGKA2A> .

[XVilka]

@alavrik for the Camlp5 problem - see camlp5/camlp5#39 and ocaml/opam-repository#14351
But I doubt it worth the trouble, OCaml 4.09 is already looming on the horizon, and camlp4/5 might be stuck without its support again. It is better to drop their support whatsoever. After all only a small bunch of the packages depend on ulex:

• beluga - created an issue #108 for porting to sedlex
• cduce
• fstar>=0.9.5.0 - created an issue #1792 for porting to sedlex
• higlo - created an issue #3 for porting to sedlex
• kremlin - created an issue #138 for porting to sedlex
• lambdoc - created an issue #37 for porting to sedlex
• mezzo
• opa-base - created an issue #196 for porting to sedlex
• pxp
• sociaml-vcard - created an issue #1 for porting to sedlex
• wdialog

[alavrik]

@XVilka I agree about ulex. There's even a branch that uses sedlex instead of ulex: https://github.com/alavrik/piqi/tree/sedlex

I was hesitant to push it in the past, because maintenance status of sedlex was unclear and ppx used to be rather unstable. I haven't revisited it since then. If you say that latest sedlex and ocaml-migrate-parsetree work well, I am fine with going this route. Would you be interested bringing this branch up-to-date and integrating it? It would be way simpler than rewriting the Piq_lexer (not a big deal too, but does require some amount of work).

[XVilka]

Thanks! I will surely check it.

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On Sat, Jun 29, 2019, 7:03 PM Anton Lavrik ***@***.***> wrote: @XVilka <https://github.com/XVilka> I agree about ulex. There's even a branch that uses sedlex instead of ulex: https://github.com/alavrik/piqi/tree/sedlex I was hesitant to push it in the past, because maintenance status of sedlex was unclear and ppx used to be rather unstable. I haven't revisited it since then. If you say that latest sedlex and ocaml-migrate-parsetree work well, I am fine with going this route. Would you be interested bringing this branch up-to-date and integrating it? It would be way simpler than rewriting the Piq_lexer (not a big deal too, but does require some amount of work). — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#62?email_source=notifications&email_token=AABRT7KSO6QIJYSNCJ5JCP3P446RFA5CNFSM4HZGKA2KYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGODY3WZBQ#issuecomment-506948742>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AABRT7PWHPEMUU2HOLTHRZDP446RFANCNFSM4HZGKA2A> .

[XVilka]

Started to work in #65

[XVilka]

Note that Camlp5 7.08 (with the support for 4.08) was released. So piqi should work fine as is right now. But it will be still better to move to sedlex.

[alavrik]

@XVilka thank you for letting me know. I agree, sedlex or even no external dependencies would be a better solution. Sorry about slow response. Will try to catch up with the pull requests soon.

[XVilka]

And the official Camlp4 deprecation announcement: https://discuss.ocaml.org/t/the-end-of-camlp4/4216

[alavrik]

I've just pushed sedlex support to master. Everything seems to be working for OCaml 4.03 through 4.08. Closing.

Note that I have also removed custom solution for building third-party dependencies. It is all managed by opam now.