Remote GHCi

[Simon Marlow]

Yes, I used the GHCJS code as a starting point for Remote GHCi - the 
implementation of TH in Remote GHCi is very similar to GHCJS.  Luite and 
I have chatted about this in person, and I believe he intends to try to 
merge them at some point.

Remote GHCi should make it possible to do TH with a cross-compiler, 
though you still need to be able to run code on the target platform at 
compile-time, like GHCJS does with nodejs.

Cheers,
Simon

On 08/01/2016 07:18, Moritz Angermann wrote:
> I’m not sure how much I can actually contribute to this, but I’ll just add a
> few pointers to nothing gets lost.  I’m not very familiar with remote ghci, but I
> think that there is some overlap between remote ghci and out of process template
> haskell compilation[1][2].  Most of ghcjs’s TH code is in src/Gen2/TH.hs.
>
> To be honest, I haven’t had much time last year to do anything for the out of
> process th stuff.  I’m planing to get back at oopth, once we got shaking-up-ghc[3]
> to build cross compilers properly. From the looks of it, that could be soon :)
>
> I only know about the ghcjs repl[4] through twitter. I’m certain luite can share a
> lot more here.
>
> With respect to remote ghci, I haven’t had much time to look into it. The main focus
> of out of process th (for me) was getting TH to work for cross compiler, which means
> shipping code to a remote process through some kind of channel that the remote allows*.
>
> Hope this might help in some way.
>
> Cheers,
> Moritz
>
> [1]: https://github.com/ghcjs/ghcjs/wiki/Porting-GHCJS-Template-Haskell-to-GHC
> [2]: https://github.com/angerman/oopth
> [3]: https://github.com/snowleopard/shaking-up-ghc
> [4]: https://twitter.com/acid2/status/614076905990582272/photo/1
> [*]: E.g. getting this to work for iOS.
>
>> On Jan 8, 2016, at 2:01 PM, Edward Z. Yang <ezyang at mit.edu> wrote:
>>
>> I was reviewing some history here, and I realized
>> that the GHCJS folks had previous implemented this:
>>
>> https://mail.haskell.org/pipermail/ghc-devs/2015-November/010478.html
>>
>> What ever happened to this line of work?  Does remote GHCi
>> subsume it?
>>
>> Edward
>>
>> Excerpts from Simon Marlow's message of 2015-11-17 02:10:55 -0800:
>>> Hi folks - I've been thinking about changing the way we run interpreted
>>> code so that it would be run in a separate process.  It turns out this
>>> has quite a few benefits, and would let us kill some of the really
>>> awkward hacks we have in GHC to work around problems that arise because
>>> we're running interpreted code and the compiler on the same runtime.
>>>
>>> I summarised the idea here: https://ghc.haskell.org/trac/ghc/wiki/RemoteGHCi
>>>
>>> I'd be interested to hear if anyone has any thoughts around this,
>>> particularly if doing this would make your life difficult in some way.
>>> Are people relying on dynCompileExpr for anything?
>>>
>>> Cheers,
>>> Simon
>