Hi Ben, I updated the wiki page for GHC 8.0.1 to add an entry for the custom type errors (under "in flight, but likely to make it"). It shouldn't be a problem to make all changes needed by the end of November. Ther phabricator link is this: https://phabricator.haskell.org/D1236 The ticket is here: https://ghc.haskell.org/trac/ghc/ticket/9637 Disclaimer: I don't really understand the phabricator work-flow, I just blindly followed the instructions on the wiki to create this, but I don't really know how to update it or make changes to it. I'd be happy to push a standard git branch, if that would be useful for you. It certainly would be easier for me, as I have a good mental model of what git does, but have only very rudimentary understanding of phabricator. -Iavor On Tue, Oct 27, 2015 at 11:27 AM, Ben Gamari wrote:

Iavor Diatchki writes:

...

Hello,

Hello!

Very good timing on the message; we just finished discussing your work not more than an hour ago. You can disregard my message; I didn't notice yours before sending it.

...

On Thu, Oct 22, 2015 at 9:47 AM, Simon Peyton Jones < simonpj@microsoft.com> wrote:

...

I’ve forgotten the state of your type-level error messages work. How’s it going?

I think we should try to add it to 8.0.1. The current status is that the idea is implemented on a branch. Then, there were some comments and suggestions that maybe we should do things in a different way, implementation wise. I haven't had a chance to look into these in detail, or implement them, and as far as I know nobody else has stepped up to make the changes. So we could simply go with the current version, and if for some reason we want to change the implementation we could do it later, as I don't think the API will be affected in any way. When do the changes need to happen by, so that it makes it in 8.0? I have been a bit busy, but I could probably find some time to make whatever changes are required for this to be merged.

OK good! In that case

· Add it to the hoped-for features in the GHC 8.01. status page

Where is the GHC 8.01 status page?

Here,

https://ghc.haskell.org/trac/ghc/wiki/Status/GHC-8.0.1

...

· Write a wiki page with a specification

...

Here is the specification:

https://ghc.haskell.org/trac/ghc/wiki/CustomTypeErros

Great! I have moved this to,

https://ghc.haskell.org/trac/ghc/wiki/Proposal/CustomTypeErrors

and left a redirect page in the old location.

Is there a Trac ticket for this?

...

...

· Announce the proposal and seek feedback

We already had a discussion about it, there are notes on the wiki. I

don't

...

think any of the comments were about the actual design, the comments seem to be more about the implementation. On that front, if I am to make the necessary changes, maybe we could have a chat (or e-mail conversation) to make sure that I understand the changes and the motivation for them---the wiki is not a great media for question/answer type of discussions.

I'll let you and Simon work this out.

...

...

· Meanwhile make sure the branch reflects what you want to be in it

I think that the branch should be in an OK state, except that it is not merged with the latest HEAD.

Where can this branch be found?

Cheers,

- Ben

It would be great to document some of these common workflows. Simon | -----Original Message----- | From: ghc-devs [mailto:ghc-devs-bounces@haskell.org] On Behalf Of Matthew | Pickering | Sent: 27 October 2015 21:10 | To: Iavor Diatchki | Cc: ghc-devs@haskell.org | Subject: Re: Type-level error messages | | Hi Iavor, | | You can update your diff by using "arc diff --update D1236" | | Matt | | On Tue, Oct 27, 2015 at 8:48 PM, Iavor Diatchki | wrote: | > Hi Ben, | > | > I updated the wiki page for GHC 8.0.1 to add an entry for the custom type | > errors (under "in flight, but likely to make it"). It shouldn't be a | > problem to make all changes needed by the end of November. | > | > Ther phabricator link is this: | > https://phabricator.haskell.org/D1236 | > | > The ticket is here: | > https://ghc.haskell.org/trac/ghc/ticket/9637 | > | > | > Disclaimer: I don't really understand the phabricator work-flow, I just | > blindly followed the instructions on the wiki to create this, but I don't | > really know how to update it or make changes to it. I'd be happy to push a | > standard git branch, if that would be useful for you. It certainly would | be | > easier for me, as I have a good mental model of what git does, but have | only | > very rudimentary understanding of phabricator. | > | > -Iavor | > | > | > | > | > | > On Tue, Oct 27, 2015 at 11:27 AM, Ben Gamari wrote: | >> | >> Iavor Diatchki writes: | >> | >> > Hello, | >> > | >> Hello! | >> | >> Very good timing on the message; we just finished discussing your work | >> not more than an hour ago. You can disregard my message; I didn't notice | >> yours before sending it. | >> | >> > On Thu, Oct 22, 2015 at 9:47 AM, Simon Peyton Jones | >> > | >> > wrote: | >> > | >> >> I’ve forgotten the state of your type-level error messages work. How’s | >> >> it | >> >> going? | >> >> | >> >> I think we should try to add it to 8.0.1. The current status is that | >> >> the | >> >> idea is implemented on a branch. Then, there were some comments and | >> >> suggestions that maybe we should do things in a different way, | >> >> implementation wise. I haven't had a chance to look into these in | >> >> detail, | >> >> or implement them, and as far as I know nobody else has stepped up to | >> >> make | >> >> the changes. So we could simply go with the current version, and if | >> >> for | >> >> some reason we want to change the implementation we could do it later, | >> >> as I | >> >> don't think the API will be affected in any way. When do the changes | >> >> need to happen by, so that it makes it in 8.0? I have been a bit | >> >> busy, | >> >> but I could probably find some time to make whatever changes are | >> >> required | >> >> for this to be merged. | >> >> | >> >> OK good! In that case | >> >> | >> >> · Add it to the hoped-for features in the GHC 8.01. status page | >> >> | >> > Where is the GHC 8.01 status page? | >> > | >> Here, | >> | >> https://ghc.haskell.org/trac/ghc/wiki/Status/GHC-8.0.1 | >> | >> > · Write a wiki page with a specification | >> >> | >> >> Here is the specification: | >> > https://ghc.haskell.org/trac/ghc/wiki/CustomTypeErros | >> > | >> Great! I have moved this to, | >> | >> https://ghc.haskell.org/trac/ghc/wiki/Proposal/CustomTypeErrors | >> | >> and left a redirect page in the old location. | >> | >> Is there a Trac ticket for this? | >> | >> > | >> >> · Announce the proposal and seek feedback | >> >> | >> > We already had a discussion about it, there are notes on the wiki. I | >> > don't | >> > think any of the comments were about the actual design, the comments | >> > seem | >> > to be more about the implementation. On that front, if I am to make the | >> > necessary changes, maybe we could have a chat (or e-mail conversation) | >> > to | >> > make sure that I understand the changes and the motivation for | >> > them---the | >> > wiki is not a great media for question/answer type of discussions. | >> > | >> I'll let you and Simon work this out. | >> | >> >> · Meanwhile make sure the branch reflects what you want to be | >> >> in | >> >> it | >> >> | >> >> I think that the branch should be in an OK state, except that it is not | >> > merged with the latest HEAD. | >> > | >> Where can this branch be found? | >> | >> Cheers, | >> | >> - Ben | > | > | > | > _______________________________________________ | > ghc-devs mailing list | > ghc-devs@haskell.org | > | https://na01.safelinks.protection.outlook.com/?url=http%3a%2f%2fmail.haskell. | org%2fcgi-bin%2fmailman%2flistinfo%2fghc- | devs&data=01%7c01%7csimonpj%40064d.mgd.microsoft.com%7c0e259c846f1d47ebdb3f08 | d2df12f101%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=jr88JSBHtublQ%2bsait% | 2bnkabrn56lpoCbOdzl7Wqx%2bYw%3d | > | _______________________________________________ | ghc-devs mailing list | ghc-devs@haskell.org | https://na01.safelinks.protection.outlook.com/?url=http%3a%2f%2fmail.haskell. | org%2fcgi-bin%2fmailman%2flistinfo%2fghc- | devs%0a&data=01%7c01%7csimonpj%40064d.mgd.microsoft.com%7c0e259c846f1d47ebdb3 | f08d2df12f101%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=jN7bTpuT1ogdIQqCHA | ughZRzNDkReaBHszrhyNlk6Mg%3d

On Oct 28, 2015, at 7:39 AM, Ben Gamari wrote:

It does look pretty reasonable but keep in mind that there are a number of comments on the Phabricator Diff that still need to be addressed.

And I have three burning questions at the bottom of the wiki page https://ghc.haskell.org/trac/ghc/wiki/Proposal/CustomTypeErrors. The first, in particular, needs to be addressed to make this feature useful. Richard