Re: [Caml-list] Camlp4-free implementation of stream parsers (was camlp4 & OCaml 4.08)

Re: [Caml-list] Camlp4-free implementation of stream parsers (was camlp4 & OCaml 4.08)

[Jocelyn Sérot]

HI Daniil,

Thanks for the example. It clearly shows how to embed a Menhir-specified parser into an existing program.

I still think, however that using Menhir for parsing arithmetic expressions is a bit overkill.

I’m having a look at Angstrom (and all the other parser combinator libs cited on the corresp. page).
It seems simpler. 

Jocelyn

Le 24 juil. 2019 à 17:31, Daniil Baturin <daniil@baturin.org> a écrit :

> Hi Jocelyn,
> 
> I've completed the first version of my project, so now I can start
> looking into this again!
> 
> There's a third option: parser combinators like angstrom.
> My experience with Menhir is very positive though. After initial
> struggle, I came to like its new incremental API and declarative error
> reporting.
> 
> Here's my parser for an extended BNF:
> Menhir grammar:
> https://github.com/dmbaturin/bnfgen/blob/master/src/bnf_parser.mly
> Parser driver that feeds it tokens:
> https://github.com/dmbaturin/bnfgen/blob/master/src/parse_bnf.ml
> Error messages:
> https://github.com/dmbaturin/bnfgen/blob/master/src/bnf_parser.messages
> Error message module build:
> https://github.com/dmbaturin/bnfgen/blob/master/src/dune#L6-L8
> 
> On 7/24/19 10:10 PM, Jocelyn Sérot wrote:
>> Hi Daniil (and everyone interested by the subject),
>> 
>> Did you have a closer look at this ? 
>> 
>> I’m still hesitating between these three approaches for replacing the implementation of the small arithm expression parser used in Lascar [1] :
>> 
>> i. rewrite it using the basic fns provided by the Stream library (pro: no additionnal dependency, cons: not so trivial..)
>> 
>> ii. replace camlp4 by camlp5 (pro: straightforward, cons: long term maintainability of camlp5 (?)) 
>> 
>> iii. rewrite it using ocamlex/menhir and embed it in the main code (pro: « standard » soon; cons: a bit heavy)
>> 
>> Jocelyn
>> 
>> [1] https://github.com/jserot/lascar/blob/master/src/lib/fsm_expr.ml, lines 70–112
>> 
>> Le 2 juil. 2019 à 11:25, Daniil Baturin <daniil@baturin.org> a écrit :
>> 
>>> Hi Jocelyn,
>>> Camlp5 is still sort of maintained, but I don't think it's going to be
>>> developed beyond compatibility updates.
>>> For syntax extensions, everyone is switching to PPX.
>>> 
>>> From a quick look, it seems like the only bit of camlp4 you use is
>>> stream expressions.
>>> This is one of the things PPX can't do (on purpose, since it doesn't
>>> allow _arbitrary_ extensions),
>>> but I don't think just using streams directly is going to make code much
>>> longer.
>>> 
>>> Or I missed some other camlp4 bits?
>>> 
>>> I'm ready to work on a patch if you are open to it.
>>> 
>>> On 7/2/19 1:44 PM, Jocelyn Sérot wrote:
>>>> Le 29 juin 2019 à 17:15, Daniil Baturin <daniil@baturin.org> a écrit :
>>>> 
>>>>> Perhaps we should make some coordinated effort to help them.
>>>>> I've just sent a pull request to the ocamldot maintainer that enables
>>>>> the graphviz files parsing and printing modules
>>>>> to build and work with 4.08. The GTK parts have their own issues.
>>>>> Next I'm going to look into LASCAR/RFSM (packages that interest me first ;).
>>>>> 
>>>> Hi Daniil,
>>>> 
>>>> I’ve been been thinking of removing the dependency of Lascar and RFSM on camlp4 for a while.
>>>> Is switching to CamlP5 a good alternative ? 
>>>> 
>>>> Jocelyn
>>>> 
>>>> 
>>> 
> 
> 

Re: [Caml-list] Camlp4-free implementation of stream parsers (was camlp4 & OCaml 4.08)

[Gabriel Scherer]

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Hi,

The parser from
https://github.com/jserot/lascar/blob/master/src/lib/fsm_expr.ml seems
fairly trivial, have you considered just rewriting it to use the functions
of the Stream primitives directly?

For example, roughly (I have not tried to type-check or test the code),

    let rec aux = parser
    | [< 'Int n when n<0; t=aux >] -> [< 'Kwd "-"; 'Int (-n); t >]
    | [< 'h; t=aux >] -> [< 'h; t >]
    | [< >] -> [< >] in

would become

    let aux s =
      let next = ref [] in
      Stream.from @@ fun _ ->
        match !next with
        | tok::toks -> next := toks; Some tok
        | [] -> match Stream.next with
                | exception Stream.Failure -> None
                | Int n when n < 0 ->
                  next := [Int (-n)];
                  Some (Kwd "-")
                | tok -> Some tok

and

    let rec p_exp0  = parser
    | [< 'Int n >] -> EConst n
    | [< 'Ident i >] -> EVar i
    | [< 'Kwd "("; e=p_exp ; 'Kwd ")" >] -> e

becomes

    let rec p_exp0 s = match Stream.next s with
    | Int n -> EConst n
    | Ident i -> EVar i
    | Kwd "(" ->
      let e = p_exp s in
      match Stream.peek s with
      | Some (Kwd ")") -> Stream.junk s; e
      | _ -> raise Stream.Failure

This is not exactly exciting code to write, but it's not a lot of work
either for such a simple grammar.

On Thu, Jul 25, 2019 at 12:28 PM Jocelyn Sérot <jocelyn.serot@uca.fr> wrote:

> HI Daniil,
>
> Thanks for the example. It clearly shows how to embed a Menhir-specified
> parser into an existing program.
>
> I still think, however that using Menhir for parsing arithmetic
> expressions is a bit overkill.
>
> I’m having a look at Angstrom (and all the other parser combinator libs
> cited on the corresp. page).
> It seems simpler.
>
> Jocelyn
>
> Le 24 juil. 2019 à 17:31, Daniil Baturin <daniil@baturin.org> a écrit :
>
> > Hi Jocelyn,
> >
> > I've completed the first version of my project, so now I can start
> > looking into this again!
> >
> > There's a third option: parser combinators like angstrom.
> > My experience with Menhir is very positive though. After initial
> > struggle, I came to like its new incremental API and declarative error
> > reporting.
> >
> > Here's my parser for an extended BNF:
> > Menhir grammar:
> > https://github.com/dmbaturin/bnfgen/blob/master/src/bnf_parser.mly
> > Parser driver that feeds it tokens:
> > https://github.com/dmbaturin/bnfgen/blob/master/src/parse_bnf.ml
> > Error messages:
> > https://github.com/dmbaturin/bnfgen/blob/master/src/bnf_parser.messages
> > Error message module build:
> > https://github.com/dmbaturin/bnfgen/blob/master/src/dune#L6-L8
> >
> > On 7/24/19 10:10 PM, Jocelyn Sérot wrote:
> >> Hi Daniil (and everyone interested by the subject),
> >>
> >> Did you have a closer look at this ?
> >>
> >> I’m still hesitating between these three approaches for replacing the
> implementation of the small arithm expression parser used in Lascar [1] :
> >>
> >> i. rewrite it using the basic fns provided by the Stream library (pro:
> no additionnal dependency, cons: not so trivial..)
> >>
> >> ii. replace camlp4 by camlp5 (pro: straightforward, cons: long term
> maintainability of camlp5 (?))
> >>
> >> iii. rewrite it using ocamlex/menhir and embed it in the main code
> (pro: « standard » soon; cons: a bit heavy)
> >>
> >> Jocelyn
> >>
> >> [1] https://github.com/jserot/lascar/blob/master/src/lib/fsm_expr.ml,
> lines 70–112
> >>
> >> Le 2 juil. 2019 à 11:25, Daniil Baturin <daniil@baturin.org> a écrit :
> >>
> >>> Hi Jocelyn,
> >>> Camlp5 is still sort of maintained, but I don't think it's going to be
> >>> developed beyond compatibility updates.
> >>> For syntax extensions, everyone is switching to PPX.
> >>>
> >>> From a quick look, it seems like the only bit of camlp4 you use is
> >>> stream expressions.
> >>> This is one of the things PPX can't do (on purpose, since it doesn't
> >>> allow _arbitrary_ extensions),
> >>> but I don't think just using streams directly is going to make code
> much
> >>> longer.
> >>>
> >>> Or I missed some other camlp4 bits?
> >>>
> >>> I'm ready to work on a patch if you are open to it.
> >>>
> >>> On 7/2/19 1:44 PM, Jocelyn Sérot wrote:
> >>>> Le 29 juin 2019 à 17:15, Daniil Baturin <daniil@baturin.org> a écrit
> :
> >>>>
> >>>>> Perhaps we should make some coordinated effort to help them.
> >>>>> I've just sent a pull request to the ocamldot maintainer that enables
> >>>>> the graphviz files parsing and printing modules
> >>>>> to build and work with 4.08. The GTK parts have their own issues.
> >>>>> Next I'm going to look into LASCAR/RFSM (packages that interest me
> first ;).
> >>>>>
> >>>> Hi Daniil,
> >>>>
> >>>> I’ve been been thinking of removing the dependency of Lascar and RFSM
> on camlp4 for a while.
> >>>> Is switching to CamlP5 a good alternative ?
> >>>>
> >>>> Jocelyn
> >>>>
> >>>>
> >>>
> >
> >
>
>
>

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Re: [Caml-list] Camlp4-free implementation of stream parsers (was camlp4 & OCaml 4.08)

[Jocelyn Sérot]

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Thanks for the suggestion, Gabriel.

It is indeed less tiresome that i had imagined.

I attach the corresponding full code (with original camlp4 formulation in comment).
Handling of the minus operator is here handled before parsing; this is not a problem since such a parser is supposed to be called on very small strings in practice.

Jocelyn

ps : i’m still wondering whether some library and/or ppx-based  generic (afap) implementation of Camlp4 stream parsers is possible..

8<—— Stream-based parser for simple arithmetic expressions (with non-negative integers)

type ident = string 

type value = int 

type t = 
  EConst of value              (** Constants *)   
| EVar of ident                (** Input, output or local variable *)
| EBinop of string * t * t     (** Binary operation *)

let keywords = ["+"; "-"; "*"; "/"; "("; ")"]

let mk_binary_minus s = s |> String.split_on_char '-' |> String.concat " - "
                      
let lexer s = s |> mk_binary_minus |> Stream.of_string |> Genlex.make_lexer keywords 

open Genlex

(* let rec p_exp0  = parser
 *                 | [< 'Int n >] -> EConst n
 *                 | [< 'Ident i >] -> EVar i
 *                 | [< 'Kwd "("; e=p_exp ; 'Kwd ")" >] -> e *)

let rec p_exp0 s =
  match Stream.next s with
    | Int n -> EConst n
    | Ident i -> EVar i
    | Kwd "(" ->
       let e = p_exp s in
       begin match Stream.peek s with
       | Some (Kwd ")") -> Stream.junk s; e
       | _ -> raise Stream.Failure
       end
    | _ -> raise Stream.Failure

(* and p_exp1  = parser
 *             | [< e1=p_exp0 ; rest >] -> p_exp2  e1 rest *)

and p_exp1 s =
  let e1 = p_exp0 s in
  p_exp2 e1 s
  
(* and p_exp2  e1 = parser
 *                | [< 'Kwd "*"; e2=p_exp1  >] -> EBinop("*", e1, e2)
 *                | [< 'Kwd "/"; e2=p_exp1  >] -> EBinop("/", e1, e2)
 *                | [< >] -> e1 *)

and p_exp2 e1 s =
  match Stream.peek s with
  | Some (Kwd "*") -> Stream.junk s; let e2 = p_exp1 s in EBinop("*", e1, e2)
  | Some (Kwd "/") -> Stream.junk s; let e2 = p_exp1 s in EBinop("/", e1, e2)
  | _ -> e1
  
(* and p_exp  = parser
 *            | [< e1=p_exp1 ; rest >] -> p_exp3  e1 rest *)

and p_exp s =
  let e1 = p_exp1 s in p_exp3 e1 s
                     
(* and p_exp3  e1 = parser
 *                | [< 'Kwd "+"; e2=p_exp  >] -> EBinop("+", e1, e2)
 *                | [< 'Kwd "-"; e2=p_exp  >] -> EBinop("-", e1, e2)
 *                | [< >] -> e1 *)

and p_exp3 e1 s =
  match Stream.peek s with
  | Some (Kwd "+") -> Stream.junk s; let e2 = p_exp s in EBinop("+", e1, e2)
  | Some (Kwd "-") -> Stream.junk s; let e2 = p_exp s in EBinop("-", e1, e2)
  | _ -> e1

let parse s = s |> lexer |> p_exp


Le 25 juil. 2019 à 13:42, Gabriel Scherer <gabriel.scherer@gmail.com> a écrit :

> Hi,
> 
> The parser from https://github.com/jserot/lascar/blob/master/src/lib/fsm_expr.ml seems fairly trivial, have you considered just rewriting it to use the functions of the Stream primitives directly?
> 
> For example, roughly (I have not tried to type-check or test the code),
> 
>     let rec aux = parser
>     | [< 'Int n when n<0; t=aux >] -> [< 'Kwd "-"; 'Int (-n); t >]
>     | [< 'h; t=aux >] -> [< 'h; t >]
>     | [< >] -> [< >] in
> 
> would become
> 
>     let aux s =
>       let next = ref [] in
>       Stream.from @@ fun _ ->
>         match !next with
>         | tok::toks -> next := toks; Some tok
>         | [] -> match Stream.next with
>                 | exception Stream.Failure -> None
>                 | Int n when n < 0 ->
>                   next := [Int (-n)];
>                   Some (Kwd "-")
>                 | tok -> Some tok
>  
> and
> 
>     let rec p_exp0  = parser
>     | [< 'Int n >] -> EConst n
>     | [< 'Ident i >] -> EVar i
>     | [< 'Kwd "("; e=p_exp ; 'Kwd ")" >] -> e        
> 
> becomes
> 
>     let rec p_exp0 s = match Stream.next s with
>     | Int n -> EConst n
>     | Ident i -> EVar i
>     | Kwd "(" ->
>       let e = p_exp s in
>       match Stream.peek s with
>       | Some (Kwd ")") -> Stream.junk s; e
>       | _ -> raise Stream.Failure
> 
> This is not exactly exciting code to write, but it's not a lot of work either for such a simple grammar.
> 
> On Thu, Jul 25, 2019 at 12:28 PM Jocelyn Sérot <jocelyn.serot@uca.fr> wrote:
> HI Daniil,
> 
> Thanks for the example. It clearly shows how to embed a Menhir-specified parser into an existing program.
> 
> I still think, however that using Menhir for parsing arithmetic expressions is a bit overkill.
> 
> I’m having a look at Angstrom (and all the other parser combinator libs cited on the corresp. page).
> It seems simpler. 
> 
> Jocelyn
> 
> Le 24 juil. 2019 à 17:31, Daniil Baturin <daniil@baturin.org> a écrit :
> 
> > Hi Jocelyn,
> > 
> > I've completed the first version of my project, so now I can start
> > looking into this again!
> > 
> > There's a third option: parser combinators like angstrom.
> > My experience with Menhir is very positive though. After initial
> > struggle, I came to like its new incremental API and declarative error
> > reporting.
> > 
> > Here's my parser for an extended BNF:
> > Menhir grammar:
> > https://github.com/dmbaturin/bnfgen/blob/master/src/bnf_parser.mly
> > Parser driver that feeds it tokens:
> > https://github.com/dmbaturin/bnfgen/blob/master/src/parse_bnf.ml
> > Error messages:
> > https://github.com/dmbaturin/bnfgen/blob/master/src/bnf_parser.messages
> > Error message module build:
> > https://github.com/dmbaturin/bnfgen/blob/master/src/dune#L6-L8
> > 
> > On 7/24/19 10:10 PM, Jocelyn Sérot wrote:
> >> Hi Daniil (and everyone interested by the subject),
> >> 
> >> Did you have a closer look at this ? 
> >> 
> >> I’m still hesitating between these three approaches for replacing the implementation of the small arithm expression parser used in Lascar [1] :
> >> 
> >> i. rewrite it using the basic fns provided by the Stream library (pro: no additionnal dependency, cons: not so trivial..)
> >> 
> >> ii. replace camlp4 by camlp5 (pro: straightforward, cons: long term maintainability of camlp5 (?)) 
> >> 
> >> iii. rewrite it using ocamlex/menhir and embed it in the main code (pro: « standard » soon; cons: a bit heavy)
> >> 
> >> Jocelyn
> >> 
> >> [1] https://github.com/jserot/lascar/blob/master/src/lib/fsm_expr.ml, lines 70–112
> >> 
> >> Le 2 juil. 2019 à 11:25, Daniil Baturin <daniil@baturin.org> a écrit :
> >> 
> >>> Hi Jocelyn,
> >>> Camlp5 is still sort of maintained, but I don't think it's going to be
> >>> developed beyond compatibility updates.
> >>> For syntax extensions, everyone is switching to PPX.
> >>> 
> >>> From a quick look, it seems like the only bit of camlp4 you use is
> >>> stream expressions.
> >>> This is one of the things PPX can't do (on purpose, since it doesn't
> >>> allow _arbitrary_ extensions),
> >>> but I don't think just using streams directly is going to make code much
> >>> longer.
> >>> 
> >>> Or I missed some other camlp4 bits?
> >>> 
> >>> I'm ready to work on a patch if you are open to it.
> >>> 
> >>> On 7/2/19 1:44 PM, Jocelyn Sérot wrote:
> >>>> Le 29 juin 2019 à 17:15, Daniil Baturin <daniil@baturin.org> a écrit :
> >>>> 
> >>>>> Perhaps we should make some coordinated effort to help them.
> >>>>> I've just sent a pull request to the ocamldot maintainer that enables
> >>>>> the graphviz files parsing and printing modules
> >>>>> to build and work with 4.08. The GTK parts have their own issues.
> >>>>> Next I'm going to look into LASCAR/RFSM (packages that interest me first ;).
> >>>>> 
> >>>> Hi Daniil,
> >>>> 
> >>>> I’ve been been thinking of removing the dependency of Lascar and RFSM on camlp4 for a while.
> >>>> Is switching to CamlP5 a good alternative ? 
> >>>> 
> >>>> Jocelyn
> >>>> 
> >>>> 
> >>> 
> > 
> > 
> 
> 


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[Caml-list] camlp4 & OCaml 4.08

[Richard W.M. Jones]

I know camlp4 is dead and all that, but we've got some software which
still uses it.  I will probably port it to camlp5 when I have the
time, but has anyone got the patch to make camlp4 work with 4.08?

Rich.

Re: [Caml-list] camlp4 & OCaml 4.08

[Anil Madhavapeddy]

On 27 Jun 2019, at 14:45, Richard W.M. Jones <rich@annexia.org> wrote:
> 
> 
> I know camlp4 is dead and all that, but we've got some software which
> still uses it.  I will probably port it to camlp5 when I have the
> time, but has anyone got the patch to make camlp4 work with 4.08?


To fork the thread slightly,  how big are the camlp4 dependencies remaining
in your codebase, and is there anything we can do to help migrate?

It's pretty exhausting trying to keep camlp4 maintained with a skeleton
crew, and there appears to be a stubborn tail of packages which aren't
migrating despite it having been quite a few years since the deprecation.

Having said that, patches for 4.08 support for camlp4 are also welcome
if anyone wants to step up to help maintain it. It's only deprecated from
the perspective of being bundled with the core compiler distribution,
and is now deprecated due to lack of programmer-will to keep it going.

regards,
Anil

Re: [Caml-list] camlp4 & OCaml 4.08

[Daniil Baturin]

On 6/29/19 4:06 PM, Anil Madhavapeddy wrote:
> On 27 Jun 2019, at 14:45, Richard W.M. Jones <rich@annexia.org> wrote:
>>
>> I know camlp4 is dead and all that, but we've got some software which
>> still uses it.  I will probably port it to camlp5 when I have the
>> time, but has anyone got the patch to make camlp4 work with 4.08?
>
> To fork the thread slightly,  how big are the camlp4 dependencies remaining
> in your codebase, and is there anything we can do to help migrate?
>
> It's pretty exhausting trying to keep camlp4 maintained with a skeleton
> crew, and there appears to be a stubborn tail of packages which aren't
> migrating despite it having been quite a few years since the deprecation.
>
> Having said that, patches for 4.08 support for camlp4 are also welcome
> if anyone wants to step up to help maintain it. It's only deprecated from
> the perspective of being bundled with the core compiler distribution,
> and is now deprecated due to lack of programmer-will to keep it going.
>
> regards,
> Anil

My feeling is that many of those packages still use camlp4 because their
maintainers haven't got time to update them,
rather than due to unending love for camlp4.
Some packages may not even actually use camlp4 at all, it's just their
build setup that requires it.

Perhaps we should make some coordinated effort to help them.
I've just sent a pull request to the ocamldot maintainer that enables
the graphviz files parsing and printing modules
to build and work with 4.08. The GTK parts have their own issues.
Next I'm going to look into LASCAR/RFSM (packages that interest me first ;).

If anyone wants to join the review and patch making process, let me know.
Maybe make a forum thread or an issue in some repo with a dependent
package checklist we can strike through.

[Caml-list] Camlp4-free implementation of stream parsers (was camlp4 & OCaml 4.08)

[Jocelyn Sérot]

Hi Daniil (and everyone interested by the subject),

Did you have a closer look at this ? 

I’m still hesitating between these three approaches for replacing the implementation of the small arithm expression parser used in Lascar [1] :

i. rewrite it using the basic fns provided by the Stream library (pro: no additionnal dependency, cons: not so trivial..)

ii. replace camlp4 by camlp5 (pro: straightforward, cons: long term maintainability of camlp5 (?)) 

iii. rewrite it using ocamlex/menhir and embed it in the main code (pro: « standard » soon; cons: a bit heavy)

Jocelyn

[1] https://github.com/jserot/lascar/blob/master/src/lib/fsm_expr.ml, lines 70–112

Le 2 juil. 2019 à 11:25, Daniil Baturin <daniil@baturin.org> a écrit :

> Hi Jocelyn,
> Camlp5 is still sort of maintained, but I don't think it's going to be
> developed beyond compatibility updates.
> For syntax extensions, everyone is switching to PPX.
> 
> From a quick look, it seems like the only bit of camlp4 you use is
> stream expressions.
> This is one of the things PPX can't do (on purpose, since it doesn't
> allow _arbitrary_ extensions),
> but I don't think just using streams directly is going to make code much
> longer.
> 
> Or I missed some other camlp4 bits?
> 
> I'm ready to work on a patch if you are open to it.
> 
> On 7/2/19 1:44 PM, Jocelyn Sérot wrote:
>> Le 29 juin 2019 à 17:15, Daniil Baturin <daniil@baturin.org> a écrit :
>> 
>>> Perhaps we should make some coordinated effort to help them.
>>> I've just sent a pull request to the ocamldot maintainer that enables
>>> the graphviz files parsing and printing modules
>>> to build and work with 4.08. The GTK parts have their own issues.
>>> Next I'm going to look into LASCAR/RFSM (packages that interest me first ;).
>>> 
>> Hi Daniil,
>> 
>> I’ve been been thinking of removing the dependency of Lascar and RFSM on camlp4 for a while.
>> Is switching to CamlP5 a good alternative ? 
>> 
>> Jocelyn
>> 
>> 
> 
> 

Re: [Caml-list] Camlp4-free implementation of stream parsers (was camlp4 & OCaml 4.08)

[Daniil Baturin]

Hi Jocelyn,

I've completed the first version of my project, so now I can start
looking into this again!

There's a third option: parser combinators like angstrom.
My experience with Menhir is very positive though. After initial
struggle, I came to like its new incremental API and declarative error
reporting.

Here's my parser for an extended BNF:
Menhir grammar:
https://github.com/dmbaturin/bnfgen/blob/master/src/bnf_parser.mly
Parser driver that feeds it tokens:
https://github.com/dmbaturin/bnfgen/blob/master/src/parse_bnf.ml
Error messages:
https://github.com/dmbaturin/bnfgen/blob/master/src/bnf_parser.messages
Error message module build:
https://github.com/dmbaturin/bnfgen/blob/master/src/dune#L6-L8

On 7/24/19 10:10 PM, Jocelyn Sérot wrote:
> Hi Daniil (and everyone interested by the subject),
>
> Did you have a closer look at this ? 
>
> I’m still hesitating between these three approaches for replacing the implementation of the small arithm expression parser used in Lascar [1] :
>
> i. rewrite it using the basic fns provided by the Stream library (pro: no additionnal dependency, cons: not so trivial..)
>
> ii. replace camlp4 by camlp5 (pro: straightforward, cons: long term maintainability of camlp5 (?)) 
>
> iii. rewrite it using ocamlex/menhir and embed it in the main code (pro: « standard » soon; cons: a bit heavy)
>
> Jocelyn
>
> [1] https://github.com/jserot/lascar/blob/master/src/lib/fsm_expr.ml, lines 70–112
>
> Le 2 juil. 2019 à 11:25, Daniil Baturin <daniil@baturin.org> a écrit :
>
>> Hi Jocelyn,
>> Camlp5 is still sort of maintained, but I don't think it's going to be
>> developed beyond compatibility updates.
>> For syntax extensions, everyone is switching to PPX.
>>
>> From a quick look, it seems like the only bit of camlp4 you use is
>> stream expressions.
>> This is one of the things PPX can't do (on purpose, since it doesn't
>> allow _arbitrary_ extensions),
>> but I don't think just using streams directly is going to make code much
>> longer.
>>
>> Or I missed some other camlp4 bits?
>>
>> I'm ready to work on a patch if you are open to it.
>>
>> On 7/2/19 1:44 PM, Jocelyn Sérot wrote:
>>> Le 29 juin 2019 à 17:15, Daniil Baturin <daniil@baturin.org> a écrit :
>>>
>>>> Perhaps we should make some coordinated effort to help them.
>>>> I've just sent a pull request to the ocamldot maintainer that enables
>>>> the graphviz files parsing and printing modules
>>>> to build and work with 4.08. The GTK parts have their own issues.
>>>> Next I'm going to look into LASCAR/RFSM (packages that interest me first ;).
>>>>
>>> Hi Daniil,
>>>
>>> I’ve been been thinking of removing the dependency of Lascar and RFSM on camlp4 for a while.
>>> Is switching to CamlP5 a good alternative ? 
>>>
>>> Jocelyn
>>>
>>>
>>