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mirror of https://github.com/idris-lang/Idris2.git synced 2024-12-26 13:11:30 +03:00
Commit Graph

3 Commits

Author SHA1 Message Date
Edwin Brady
ad632d825d Remove linearity subtyping
It's disappointing to have to do this, but I think necessary because
various issue reports have shown it to be unsound (at least as far as
inference goes) and, at the very least, confusing. This patch brings us
back to the basic rules of QTT.

On the one hand, this makes the 1 multiplicity less useful, because it
means we can't flag arguments as being used exactly once which would be
useful for optimisation purposes as well as precision in the type. On
the other hand, it removes some complexity (and a hack) from
unification, and has the advantage of being correct! Also, I still
consider the 1 multiplicity an experiment.

We can still do interesting things like protocol state tracking, which
is my primary motivation at least.

Ideally, if the 1 multiplicity is going to be more generall useful,
we'll need some kind of way of doing multiplicity polymorphism in the
future. I don't think subtyping is the way (I've pretty much always come
to regret adding some form of subtyping).

Fixes  (and maybe some others).
2020-12-27 19:58:35 +00:00
Edwin Brady
84adbe6dc8 Be explicit about multiplicity in Array
The bootstrap version can't infer it!
2020-06-12 14:18:57 +01:00
Edwin Brady
1c576cb068 Add experimental support for linear arrays
Backed by Data.IOArray. Also moved the array external primitives to a
separate module Data.IOArray.Prims, since the next step is to add a
linear bounded array type where the bounds checks are done at compile
time, so we'll want to read and write without bounds likes.
2020-06-12 14:08:00 +01:00