We've been wrongly representing large ints as BigInt, causing them to
behave differently in the VM through builtins like 'serialise_data'.
Indeed, we expect anything that fits in 8 bytes to be encoded as Major
Type 0 or 1. But we were switching to encoding as Major type 6
(tagged, PosBigInt, NegBigInt) for much smaller values! Anything
outside of the range [-2^32, 2^32-1] would be treated as big int
(positive or negative).
Why? Because we checked whether a value i would fit in an i64, and if
it didn't we treated it as big int. But the reality is more subtle...
Fortunately, Rust has i128 and the minicbor library implements TryFrom
which enforces that the value fits in a range of [-2^64, 2^64 - 1], so
we're back on track easily.
This improves error messages for `a |> b(x)`.
We need to do a special check when looping over the args
and unifying. This information is within a function that does not belong
to pipe typer so I used a closure to forward along a way to add
metadata to the error when the first argument in the loop has a
unification error. Simply adding the metadata at the pipe typer
level is not good enough because then we may annotate regular
unification errors from the args.
The 'HEAD' call that is done to resolve package revisions from
unpinned versions is already quite cheap, but it would still be better
to avoid overloading Github with such calls; especially for users of a
language-server that would compile on-the-fly very often. Upstream
packages don't change often so there's no need to constantly check the
etag.
So we now keep a local version of etags that we fetched, as well as a
timestamp from the last time we fetched them so that we only re-fetch
them if more than an hour has elapsed. This should be fairly resilient
while still massively improving the UX for people showing up after a
day and trying to use latest 'main' features.
This means that we now effectively have two caching levels:
- In the manifest, we store previously fetched etags.
- In the filesystem, we have a cache of already downloaded zip archives.
The first cache is basically invalidated every hour, while the second
cache is only invalidated when a etag changes. For pinned versions,
nothing is invalidated as they are considered immutable.
KtorZ