Constants are like tiny programs, so they are bound by the same rules
as validators and other programs. In fact, functions are slightly more
flexible in that they allow generic constant expressions like
`List<a>`.
Yet, there is no way to contain such generic structure that contain
inhabitants in a way that satisfies the type-checker. In the example
of `List<a>`, the only inhabitant of that type that we can construct
is the empty list. Anything else would require holding onto some
generic value.
In addition, we can't force literal values into generic annotation, as
something like:
```
const foo: List<a> = [1, 2, 3]
```
wouldn't type-check either since the right-side would unify to
`List<Int>`. And again, the only right-hand side that can type-check
is the empty list without any inhabitant.
The added restriction on generic function is necessary because while
we allow constants to return lambda, we cannot (easily) generate UPLC
that is generic in its argument. By the time we generate UPLC, the
underlying types have to be known.
This is not a "proper" fix as it simply get rid of the warning
altogether (whether you use or not the destructured values).
The reason for removing the warning entirely is because (1) it's
simpler, but more so (2) there's no impact on the final code produced
_anyway_. Redundant let bindings are already removed by the compiler;
and while it's an implicit behaviour that requires a proper warning
when it's coming from a user-defined assignment; here the redundant
assignment is introduced by the compiler to begin with as another
implicit behavior!
So we have an implicit behaviour triggering a warning on another
implicit behaviour. Truth is, there's no impact in having those
parameters destructured and unused. So since users are already not
aware that this results in an implicit let assignment being inserted
in place for them; there's no need for the warning at all.
Avoid the interface to hang for several seconds without feedback when counterexamples are being simplified. This sends a heads-up to the user to indicate that a research of a counter example is going on.
For recursive structures like Tuples, the span itself isn't enough to
ensure uniqueness of elements (in particular tuples) holding elements
of the same type.
This is only a start. It compiles, but with a few TODOs left open. In particular, it doesn't currently handle constants depending on other constants or functions; nor does it hoist constants.
The playground doesn't / cannot depend on aiken-project because that becomes a gigantic pain. So instead, we try to keep essential stuff inside aiken-lang when possible.
Technically, we always need a fallback just because the way the UPLC
is going to work. The last case in the handler pattern matching is
always going to be else ...
We could optimize that away and when the validator is exhaustive, make
the last handler the fallback. Yet, it's really a micro optimization
that saves us one extra if/else. So the sake of getting things
working, we always assume that there's a fallback but, with the extra
condition that when the validator is exhaustive (i.e. there's a
handler covering all purposes), the fallback HAS TO BE the default
fallback (i.e. (_) => fail).
This allows us to gracefully format it out, and also raise an error in
case where there's an extraneous custom fallback.
When there's no type annotation in a validator handler signature, we
provide default annotation to help the type-checker. However, for
spend's datum and mint policy_id, those annotations mustn't be `Data`,
but rather Option<Data> and Bytearray.
Without that, when no annotation are provided, the compiler infer
invalid types and fails with incongruous errors.