This commit introduces support for AST macros and templates, enabling
users to define and use custom, reusable components within the visual
DSL.
Key changes include:
- A new `MacroRegistry` to manage macro definitions.
- A `MacroExpander` to process macro calls and expand templates.
- A `MacroEvaluator` trait for evaluating expressions during expansion.
- The `Expansion` node in `BoundKind` to preserve the original macro
call and its expanded form for debugging.
- Updates to the `Binder`, `Dumper`, and `UpvalueAnalyzer` to handle the
new macro constructs.
- New examples demonstrating various macro functionalities like
`unless`, splicing, and nested macros.
The `eval` and `eval_observed` methods in the `VM` struct were very
similar, with the primary difference being the call to the `VMObserver`
trait. This commit refactors these methods into a single macro,
`dispatch_eval!`, which reduces code duplication and improves
maintainability.
The `Value::TailCallRequest` variant was also updated to use `Box` for
its contents, which helps keep the `Value` enum size consistent.
Finally, the benchmarks in the `examples` directory have been updated to
reflect minor performance changes resulting from these code
modifications.
The `UpvalueAnalyzer` now correctly identifies which lambdas capture
which variable declarations, rather than just marking declarations that
need boxing. This information is stored in a `capture_map`.
The `Binder` has been updated to use this new `capture_map` instead of a
`HashSet` of boxed declarations. The `DefLocal` node in `bound_nodes.rs`
now stores a `captured_by` field, which is a list of lambda identities
that capture the local variable.
A new `dumper` module has been added to provide a human-readable
representation of the bound AST, including information about captured
variables.
The `VM` has been updated to use the `captured_by` field to determine if
a local variable needs to be stored in a `Cell`, rather than relying on
a boolean `is_boxed` flag.
An example script `extreme_capture.myc` has been added to test deep
nesting and variable capture.
A new "Dump AST" button has been added to the UI, which uses the new
`Dumper` to display the bound AST.
Michael Schimmel