The `series` constructor now only accepts the `lookback` limit. The
element type is inferred by the type checker and implicitly added as a
schema argument during compilation. This simplifies the API and
centralizes type inference.
This change also includes:
- Updates to example scripts (`HMA.myc`, `sma.myc`, `soa_series.myc`) to
reflect the new `series` signature.
- Modifications to the `TypeChecker` to handle the inferred schema
injection.
- An addition of a regression test for type inference through nested
closures with `series`.
- Removal of `#[allow(dead_code)]` from several `TypeChecker` methods as
they are now used.
- Update to `rtl/prelude.myc` macro `cache`.
- Update to `rtl/series/mod.rs` to reflect new signature.
- Update to `ast/types.rs` to allow `series` to be indexed with an
integer to retrieve its element type.
Brummel