[Haskell-cafe] Cannot update a field in a record with a polymorphic type.

Tom Ellis tom-lists-haskell-cafe-2017 at jaguarpaw.co.uk
Thu Sep 10 10:03:59 UTC 2020

On Thu, Sep 10, 2020 at 02:47:23PM +0500, Ignat Insarov wrote:
> What I meant to express is that this problem _does not need to occur_
> with record updates, even though they are presently being desugared to
> functions. In other words, I propose that record updates _are_ special
> — or _should be_ special, in any case.

Ah, I see.  You are saying that record updates can have a special
typing rule because we have extra information that tells us that the
type of the result cannot depend on the type of what was previously

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