OCaml 4.02.X support

[struktured]

Would be excited to use the ppx_tools lib, which depends on 4.02.0 or higher. Is there a road map for upgrading the ocamljava compiler version?

[xclerc]

My goal is to release an alpha3 version during March; this
release will be focused on libraries (enhancement of javalib,
partial rewrite of concurrent), documentation, and will feature
some bugfixes.

Then, I will work on the runtime library and the update to 4.02.x.
Hopefully, this should be released in April/May.

[struktured]

Great, thanks for the quick response on this!

[pron]

Hi. Any news on that?

[xclerc]

Unfortunately not. I got a new job in a start-up company (February), and
the bad news is that it is really time consuming...
The good news is that the aforementioned start-up will use OCaml-Java
in production. Moreover, the codebase would benefit from annotations,
so there will be a strong incentive to allocate some of my time to the
upgrade to 4.02.x.

[talios]

Did anything ever come of upgrading the system to use 4.02.x? And if so, hopefully 4.03 now that it's out ( and in dream land - support for Facebooks Reason could be interesting ).

[xclerc]

I just started the work of updating to 4.03.

Don't hold your breath, however: it will be a major
update due to numerous changes in the OCaml
compiler code base.

[dannywillems]

@xclerc Any news about 4.03? (or 4.04?)

[xclerc]

I am currently porting Barista (the library used for Java class file
manipulation) to 4.04. In the process, major changes have occurred:
support for Java 8 and 9, move from camlp4 to ppx, use of new OCaml
(language) features, etc.

Once Barista is finalized, I will switch to OCaml-Java itself; the next
version should hopefully be available at the end of 2017T1.

[dannywillems]

@xclerc Seems awesome! Thanks for your job.
Do you think it's possible to write Android applications with ocaml-java? I never tried for the moment.

[xclerc]

I'm afraid it is not possible to write Android apps with OCaml-Java.

The first problem is that, to the best of my knowledge, Android does
not fully support Java 1.7 while OCaml-Java relies for example on
method handles (that are 1.7-specific).

Even if this problem were solved, either by Android support of 1.7
or through some kind of "backport", there would be another problem:
OCaml-Java allows one to implement an interface (through a proxy),
but does not allow to extend a class. This restriction would bite you
quite soon, as you need to extends Activity even for a very simple
Android app (at least it was the case the last time I checked).

[the second problem is likely to be addressed in future OCaml-Java version]

[talios]

@xclerc latest Android ( 7 and higher ) actually now support Java 8. See https://developer.android.com/guide/platform/j8-jack.html

[xclerc]

That's (possibly) good news!

The "possibly" stems from the fact that, although Android
now supports Java 8, it support seems to be different from
the one in the JDK. For example, there is no java.lang.invoke
package -- see:
https://developer.android.com/reference/packages.html

There are possibly equivalent classes, but this means that
the support for Android has to be explicit in Ocaml-Java
(and that binaries compiled for Android/JDK would be
incompatible).