[Caml-list] OASIS circular dependency in xml-light

[Caml-list] OASIS circular dependency in xml-light

[Olaf Hering]

How can I fix the circular depencency reported by oasis when converting
the xml-light to use _oasis for building?

https://github.com/ncannasse/xml-light

Circular dependencies: "xml.cmo" already seen in [ "dtd.cmo"; "xml.cmo" ]

I tried various things in _oasis, including this:

+Library "xml-light"
+  Path: .
+  Modules: Xml
+  InternalModules: Dtd, Xml_lexer, XmlParser

Thanks,

Olaf

Re: [Caml-list] OASIS circular dependency in xml-light

[Daniel Bünzli]

This doesn't answer your question but if you are trying to use xml-light for one of your project I'd advise against using it as it is absolutely not standard compliant, which will be a pain for you or your users at some point. There are a few other alternatives like markup.ml, pxp or xmlm which are.

Best, 

Daniel

Re: [Caml-list] OASIS circular dependency in xml-light

[Olaf Hering]

On Fri, Jun 10, Daniel Bünzli wrote:

> This doesn't answer your question but if you are trying to use
> xml-light for one of your project I'd advise against using it as it is
> absolutely not standard compliant, which will be a pain for you or
> your users at some point. There are a few other alternatives like
> markup.ml, pxp or xmlm which are.

There is virt-top which uses this lib. I guess it uses it to peek into
libvirt xml data for the running VMs.

Olaf

Re: [Caml-list] OASIS circular dependency in xml-light

[Adrien Nader]

XML-light is overall a nice and simple library but it's unmaintained
with known bugs and unknown or unpublicized ones too. I think it hasn't
been maintained for a decade.

-- 
Adrien Nader

Re: [Caml-list] OASIS circular dependency in xml-light

[Adrien Nader]

Well, it has seen some development in the past couple years on github.

Anyway, back to the original problem.

xml.ml references Dtd
dtd.ml references Xml (through 'open Xml', which is needed)

xml.mli does not reference Dtd
dtd.mli references Xml

Currently xml.mli is compiled, then dtd.mli, then dtd.ml and finally
xml.ml (there are other modules involved but they don't seem to be
involved in the loop). I'm not completely surprised this works but I
didn't know it was possible (my current version here is 4.01.0 but it
has probably been that way for a long time). Maybe someone else can
comment on that.

I'm actually wondering how this works wrt module initialization order.

I think the sure way would be to move at least some declarations to a
separate module that has no dependency on others and which both Xml and
Dtd could depend on.

-- 
Adrien Nader

Re: [Caml-list] OASIS circular dependency in xml-light

[Gabriel Scherer]

I have the same memories of tricky circular dependencies from looking
at the xml-light sources a while ago, and if I remember correctly
there were some really shady Obj.magic going on at the same time. If
people depend on this library, the best fix is probably to clean it up
in these respects.

On Sat, Jun 11, 2016 at 4:20 AM, Adrien Nader <adrien@notk.org> wrote:
> Well, it has seen some development in the past couple years on github.
>
> Anyway, back to the original problem.
>
> xml.ml references Dtd
> dtd.ml references Xml (through 'open Xml', which is needed)
>
> xml.mli does not reference Dtd
> dtd.mli references Xml
>
> Currently xml.mli is compiled, then dtd.mli, then dtd.ml and finally
> xml.ml (there are other modules involved but they don't seem to be
> involved in the loop). I'm not completely surprised this works but I
> didn't know it was possible (my current version here is 4.01.0 but it
> has probably been that way for a long time). Maybe someone else can
> comment on that.
>
> I'm actually wondering how this works wrt module initialization order.
>
> I think the sure way would be to move at least some declarations to a
> separate module that has no dependency on others and which both Xml and
> Dtd could depend on.
>
> --
> Adrien Nader
>
> --
> Caml-list mailing list.  Subscription management and archives:
> https://sympa.inria.fr/sympa/arc/caml-list
> Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
> Bug reports: http://caml.inria.fr/bin/caml-bugs

Re: [Caml-list] OASIS circular dependency in xml-light

[Gabriel Scherer]

I sent a preliminary pull request to break the cycles at
  https://github.com/ncannasse/xml-light/pull/3

Any comments are welcome, but we could move the discussion to this pull request.

On Sat, Jun 11, 2016 at 8:03 AM, Gabriel Scherer
<gabriel.scherer@gmail.com> wrote:
> I have the same memories of tricky circular dependencies from looking
> at the xml-light sources a while ago, and if I remember correctly
> there were some really shady Obj.magic going on at the same time. If
> people depend on this library, the best fix is probably to clean it up
> in these respects.
>
> On Sat, Jun 11, 2016 at 4:20 AM, Adrien Nader <adrien@notk.org> wrote:
>> Well, it has seen some development in the past couple years on github.
>>
>> Anyway, back to the original problem.
>>
>> xml.ml references Dtd
>> dtd.ml references Xml (through 'open Xml', which is needed)
>>
>> xml.mli does not reference Dtd
>> dtd.mli references Xml
>>
>> Currently xml.mli is compiled, then dtd.mli, then dtd.ml and finally
>> xml.ml (there are other modules involved but they don't seem to be
>> involved in the loop). I'm not completely surprised this works but I
>> didn't know it was possible (my current version here is 4.01.0 but it
>> has probably been that way for a long time). Maybe someone else can
>> comment on that.
>>
>> I'm actually wondering how this works wrt module initialization order.
>>
>> I think the sure way would be to move at least some declarations to a
>> separate module that has no dependency on others and which both Xml and
>> Dtd could depend on.
>>
>> --
>> Adrien Nader
>>
>> --
>> Caml-list mailing list.  Subscription management and archives:
>> https://sympa.inria.fr/sympa/arc/caml-list
>> Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
>> Bug reports: http://caml.inria.fr/bin/caml-bugs