Just as a heads up. You can achieve what you want already by doing:
f @_ @([String]) /:: forall a. (a, ///[String]/) -> (///[String]/, a)
/
Best regards,
Rowan Goemans
On 8/4/20 7:45 PM, Anselm Schüler (conversations subemail) wrote:
Thank you for the nice introduction :) !
I will check out the GHC proposals site.
And following Simon’s (I hope addressing with first name is OK)
suggestion, I’m going to give an outline of the idea.
The idea is to extend type application syntax to enable explicit
assignment of types to specific type variables.
For instance, say I have f :: forall a b. (a, b) -> (b, a), and I want
to apply the type [String]to it. My only option is to do
f @([String]) /:: forall b. ([String], b) -> (b, [String]) /
—but what if, instead, I want a function of type forall a. (a,
[String]) -> ([String], a)?
I propose the following syntax:
f @{b = [String]} /:: forall a. ([String], b) -> (b, [String])/
This wouldn’t break any existing programs since using record syntax
here is already disallowed and met with an error message.
A question is of course the symbol used for assignment (~, =, ::, or ->?).
I hope the code shows up as a monospace font on your end. I used the
IBM Plex Mono font, which is open-source <https://github.com/IBM/plex>.
/Anselm Schüler/
/www.anselmschueler.com <http://www.anselmschueler.com>/
/m...@anselmschueler.com <mailto:m...@anselmschueler.com>/
*From: *Simon Peyton Jones <mailto:simo...@microsoft.com>
*Sent: *Tuesday, August 4, 2020 18:44
*To: *Richard Eisenberg <mailto:r...@richarde.dev>; "Anselm Schüler
(conversations subemail)" <mailto:conversat...@anselmschueler.com>
*Cc: *ghc-devs@haskell.org <mailto:ghc-devs@haskell.org>
*Subject: *RE: Hi. I'm new to this mailing list and have a few questions.
Welcome Anselm. ghc-devs is a very informal mailing list, and we
welcome newcomers.
For example, I have a feature idea in the back of my mind, which I
imagine would be easy to implement
What Richard says is right, but you should feel free to fly the kite
on this list if you want – or on Haskell Café – to get some idea of
whether others seem warm about the idea, before writing a full proposal.
Simon
*From:* ghc-devs <ghc-devs-boun...@haskell.org> *On Behalf Of *Richard
Eisenberg
*Sent:* 04 August 2020 16:05
*To:* "Anselm Schüler (conversations subemail)"
<conversat...@anselmschueler.com>
*Cc:* ghc-devs@haskell.org
*Subject:* Re: Hi. I'm new to this mailing list and have a few questions.
Hi Anselm,
Welcome!
A good way of getting used to a list like this one is to wait a little
while and observe what kind of messages others send; this will give
you a feel for how the list is used. If you're impatient, you can also
check out the archives at https://mail.haskell.org/pipermail/ghc-devs/
<https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fmail.haskell.org%2Fpipermail%2Fghc-devs%2F&data=02%7C01%7Csimonpj%40microsoft.com%7Ce68e6131af494519061c08d83887d962%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637321503404154244&sdata=w4QIMTGeMQ35bEo4xkOn2rIj8z02iMVje4Ar9AXM22k%3D&reserved=0>.
As for a feature request: if your feature changes the language GHC
accepts (most do), the right place to post is at
https://github.com/ghc-proposals/ghc-proposals
<https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fghc-proposals%2Fghc-proposals&data=02%7C01%7Csimonpj%40microsoft.com%7Ce68e6131af494519061c08d83887d962%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637321503404164244&sdata=ogVVk5kRFXPc81dZ%2FiyGV9FbgQoQUtzazpFGcrAKUXA%3D&reserved=0>.
There is a description of how to proceed on that page. Proposals
submitted there get debated within the community and then eventually
sent to a GHC Steering Committee for a vote on acceptance or
rejection. Then, we worry about implementing it. If you have a
suggestion that does not change the language GHC accepts, you can post
an Issue at https://gitlab.haskell.org/ghc/ghc/
<https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitlab.haskell.org%2Fghc%2Fghc%2F&data=02%7C01%7Csimonpj%40microsoft.com%7Ce68e6131af494519061c08d83887d962%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637321503404164244&sdata=tg40q%2B9%2BW5KcVzHsPx9oCP7wdw5ipdZCOOdFnzUz3mU%3D&reserved=0>.
I hope this is helpful!
Richard
On Aug 4, 2020, at 8:59 AM, Anselm Schüler (conversations
subemail) <conversat...@anselmschueler.com
<mailto:conversat...@anselmschueler.com>> wrote:
First of all, in general, I’m new to mailing lists (as used for
discussions) in general, so a question about that:
When subscribed to the mailing list, do you get/every/message, or
are some discussions hidden?
Second of all, I’d like to know what kinds of messages are
appropriate here. I’m not familiar with coding compilers or
anything of the like, so I’m somewhat afraid of offering unhelpful
comments or being just woefully underqualified to participate here.
For example, I have a feature idea in the back of my mind, which I
imagine would be easy to implement (that might be wrong). Is it
alright if I submit that here or should I use some other forum?
Thank you in advance for the answers.
/Anselm Schüler/
/www.anselmschueler.com
<https://nam06.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.anselmschueler.com%2F&data=02%7C01%7Csimonpj%40microsoft.com%7Ce68e6131af494519061c08d83887d962%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637321503404164244&sdata=WJBJ3P%2BFUnTmVs9Z97DHLat9mHr6vC22l0mQ36nafGc%3D&reserved=0>/
/m...@anselmschueler.com <mailto:m...@anselmschueler.com>/
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