Optional single-child slots return T? with a real null instead of a role
null-object, taking the C# grammar as the oracle for which slots are optional.
The generator emits the property type as T? and matches it with MatchOptional,
and consumers move from .IsNull to is null / ?.. This covers the optional
statement, member, try-catch, creation-initializer and pattern slots and the
optional NameSlot tokens. A few slots the grammar marks required but the
decompiler legitimately leaves empty (the implicit-element-access target, an
implicitly-typed lambda parameter's type) are flipped to nullable as well.
Assisted-by: Claude:claude-opus-4-8:Claude Code
Introduce the successor to node.Role for child-slot identity: the generator
emits a CSharpSlotInfo per [Slot], exposed as node.Slot, plus a shared SlotKind
enum for the polymorphic "is this node in an embedded-statement / condition /
base-type slot?" comparisons a per-node identity cannot express. Migrate the
printer and transform position checks from node.Role to node.Slot and
node.Slot.Kind, and read identifier children and role-keyed writes through the
typed properties. Role is still present and is removed later; output is
unchanged.
Assisted-by: Claude:claude-opus-4-8:Claude Code
* Parenthesize interpolations containing global::
* Improvements:
* Cleaner output
* More unit testing
* More efficient tree search
* Implement revisions
* Update Lambda1 to be invariant
* Visit descendents before deciding whether or not to parenthesize an interpolation expression
* Rename local function
* Remove branch for conditional expressions
* Handle Lambda expressions without a block body
* Check for parenthesized expressions
* `NET60` instead of `!NET40`
This initial commit only handles the trivial case where an Index or Range object is constructed.
The TODO portions of the test case show there are plenty of cases where where the C# compiler emits more complex code patterns that will require ILAst transforms.