This isn't sufficient however, as the 'assignment' helper handling
code generation doesn't perform any check when patterns are vars. This
is curious, and need to be investigated further.
- Doesn't allow pattern-matching on G1/G2 elements and strings,
because the use cases for those is unclear and it adds complexity to
the feature.
- We still _parse_ patterns on G1/G2 elements and strings, but emit an
error in those cases.
- The syntax is the same as for bytearray literals (i.e. supports hex,
utf-8 strings or plain arrays of bytes).
There are currently two zero-arg builtins:
- mkNilData
- mkNilPairData
And while they have strictly speaking no arguments, the VM still
requires that they are called with an extra unit argument applied.
While this builtin is readily available through the Aiken syntax
`[head, ..tail]`, there's no reason to not support its builtin form
even though we may not encourage its usage. For completeness and to
avoid bad surprises, it is now supported.
Fixes#964.
The original goal for this commit was to allow casting from Data on
patterns without annotation. For example, given some custom type
'OrderDatum':
```
expect OrderDatum { requested_handle, destination, .. }: OrderDatum = datum
```
would work fine, but:
```
expect OrderDatum { requested_handle, destination, .. } = datum
```
Yet, the annotation feels unnecessary at this point because type can
be inferred from the pattern itself. So this commit allows, whenever
possible (ie when the pattern is neither a discard nor a var), to
infer the type from a pattern.
Along the way, I also found a couple of weird behaviours surrounding
this kind of assignments, in particular in combination with let. I'll
highlight those in the next PR (#979).
Actually, this has been a bug for a long time it seems. Calling any
prelude functions using a qualified import would result in a codegen
crash. Whoopsie.
This is now fixed as shown by the regression test.
While we agree on the idea of having some ways of emitting events, the
design hasn't been completely fleshed out and it is unclear whether
events should have a well-defined format independent of the framework
/ compiler and what this format should be.
So we need more time discussing and agreeing about what use case we
are actually trying to solve with that.
Irrespective of that, some cleanup was also needed on the UPLC side
anyway since the PR introduced a lot of needless duplications.
Refactor get_uplc_type to account for constr types that don't exactly resolve to a uplc type
Check arg_stack in uplc generator has only 1 argument at the end of the generation
warning fixes
Before this commit, we would parse 'Pair' as a user-defined
data-types, and thus piggybacking on that whole record system. While
perhaps handy for some things, it's also semantically wrong and
induces a lot more complexity in codegen which now needs to
systematically distinguish every data-type access between pairs, and
others.
So it's better to have it as a separate expression, and handle it
similar to tuples (since it's fundamentally a 2-tuple with a special
serialization).
Currently, pattern-matching on 'Pair' is handled by treating Pair as a
record, which comes as slightly odd given that it isn't actually a
record and isn't user-defined. Thus now, every use of a record must
distinguish between Pairs and other kind of records -- which screams
for another variant constructor instead.
We cannot use `Tuple` either for this, because then we have no ways to
tell 2-tuples apart from pairs, which is the whole point here. So the
most sensical thing to do is to define a new pattern `Pair` which is
akin to tuples, but simpler since we know the number of elements and
it's always 2.