wscl VS ghc-proposals

You can't seriously say that, just because one targets a well-specified machine, that the language being used is well-specified. The determinism of a Clojure-on-JVM program would also be dependent on the particular code the Clojure compiler generates. In Common Lisp there is the Armed Bear Common Lisp implementation, which runs on a JVM. Does it benefit from JVM determinism or not? It probably does not, because the JVM is simply not aware of undefined behaviour that ABCL or Clojure are implicitly defining.

When it comes to having different platforms, it would also be necessary for any other compilers to generate semantically identical code. Different Clojure systems do _not_ do that. For example, arithmetic in ClojureScript uses JS floats where Clojure-on-JVM and others use integers of some size.

In my experience, writing a non-conforming CL program is hard, and much harder than writing a program without undefined behaviour in C. I am not sure why, other than vaguely suggesting the UB is more "localised" in some way. But there is also a modification of the ANSI standard being worked on, which attempts to eliminate undefined behaviour <https://github.com/s-expressionists/wscl>.

Common Lisp was standardised by an ANSI committee. Here is a list of issues that were voted on. Nowadays there is also the Well Specified Common Lisp project, but no issues have been voted on yet.

SICL is still an implementation of Common Lisp, and not of a new programming language (give or take some additional features, such as first-class global environments). That said, there is some overlap between the authors of SICL and the authors of Well Specified Common Lisp <https://github.com/s-expressionists/wscl>; but WSCL only really defines some undefined and contradictory behaviour in the ANSI Common Lisp specification.

The HyperSpec is a (derived work of a) language specification - its job is precisely to explain infrequently used things in too much detail. (And it ironically fails in many places.) Generally, one does not want to read a specification, unless they know they need to check something specific.

This is really just a matter of how much syntax sugar you want to implement. Idris has this already, and there’s a proposal to add it to Haskell too [0]. But none of this changes the core properties of the system which make it monadic.

[0] https://github.com/ghc-proposals/ghc-proposals/issues/527

> I think Haskell needs a way to graduate (or retire) language extensions

https://github.com/ghc-proposals/ghc-proposals/pull/601

Additionally, while this proposal is focused on the simple implementation and so in the current proposal or patterns do not bind any variables as per #522, if we do get settled on syntax and then later wish to expand to allow binding variables as in #43, then the syntax is again clean and discoverable.

Yeah, a relatively natural thing would be to be able to opt-in to having the HasField instances be available in all contexts. The (not yet implemented, but accepted) "Modifiers" GHC proposal might be nice for that.

The local modules proposal imo is excellent as-is.

Why would you drop TypeFamilies? It seems fairly popular, given that it was just one vote short of getting added to GHC2021. Do you consider it a less-ideal compromise, that is subsumed by your second proposal (Core with GRTT)?

as syntax is contentious a topic as ever, David (the main proposal author) and I would like to invite you to give your input on https://github.com/ghc-proposals/ghc-proposals/pull/585, where we propose to change the syntax of the accepted proposal #522 introducing Or patterns. In particular, we'd like to know

This looks great, congratulations on completing it! I assume you didn’t get an opportunity to evaluate the delimited continuations based eff library? It would’ve been nice to see Cont included as one of the effects covered, though perhaps not available in all the systems you looked at? Maybe some future work.

I do hope qualified exports are available someday: https://github.com/ghc-proposals/ghc-proposals/pull/283

Right. Being able to disable "custom type warnings" at use sites was part of an earlier proposal (https://github.com/ghc-proposals/ghc-proposals/pull/454) but it ended up being shelved.