feat: evaluate compile-time aggregates and explicit expressions

README.md

@@ -98,7 +98,9 @@ main proc() i16 {
 
 the specialization checkpoint supports type arguments and constant integer, boolean, string, callback and null value arguments; declared value-parameter types survive specialization, including narrow checked arithmetic and optional captures/unwrap. integer arguments are range-checked even when unused, and erased argument expressions still receive ordinary checking. immutable constant expressions may use unary signs, `!`, `+`, `-`, `*`, comparisons and logical operators. type-producing procedures require compile-time parameters (or no parameters) and support immutable locals, conditional returns, nested type-producing calls and generated record/array storage, including pointer-recursive records. runaway specialization is diagnosed at 128 nested evaluation/specialization calls or 4096 instances.
 
-ordinary procedures may compute integer, boolean and string compile-time arguments from constant inputs, such as `Fixed(i16, length(2))`. calls reuse the ordinary checker, typed IR and interpreter, preserving local type inference, checked arithmetic, mutable locals, range/while loops, break/continue and recursive or specialized helper calls. each evaluation is isolated and limited to 100,000 IR instructions/terminators and 128 active frames; failures retain their originating source locations. runtime parameters and mutable global dependencies cannot supply compile-time inputs, and executed foreign calls remain interpreter traps. aggregate/type-valued execution, explicit `$()` expressions, reflection, `inline` expansion and existing generic-library acceptance remain outside this checkpoint.
+ordinary procedures may compute integer, boolean, float and string compile-time arguments and return nested records/tuples and fixed arrays from constant inputs, such as `Fixed(i16, length(2))`. calls reuse the ordinary checker, typed IR and interpreter, preserving local type inference, checked arithmetic, mutable locals, range/while loops, break/continue and recursive or specialized helper calls. aggregate arguments receive their declared context, including dependent `[N]T` parameters; cached specializations compare normalized values, not literal spelling or evaluation identity. returned aggregates become owned source literals before temporary interpreter storage is released, preserving by-value copies, exact integer types, string bytes, enum fields, optional fields and IEEE float bits.
+
+`$(expression)` explicitly evaluates a constant expression, including an ordinary procedure call, even in a package without templates. use a typed expression when its shape cannot be inferred independently, such as `$(Point { x = 40 })`; integer literals retain contextual typing. the resulting value works in runtime expressions, bindings and array lengths, while the erased expression still receives ordinary checking. each interpreter evaluation is isolated and limited to 100,000 IR instructions/terminators and 128 active frames; failures retain their originating source locations. runtime parameters and mutable local/global dependencies cannot supply compile-time inputs. data pointers, slices, callbacks, unions and fallible results cannot escape temporary evaluation as generated constants; records/arrays containing these unsupported values are diagnosed rather than retaining interpreter handles. executed foreign calls remain interpreter traps. general type-valued execution, compile-time branch/`inline` expansion, reflection, generated type/default arrays and existing generic-library acceptance remain open.
 
 callback signatures use `@proc(value i16) i16`, including grouped parameter names and trailing commas. compatible named functions can initialize callbacks, which may be passed, returned, replaced and stored in records/arrays; `Callback :: alias @proc(value i16) i16` names a reusable signature. parameter/result types match structurally, retaining nominal record identity and exact pointer mutability. callback fields call directly, such as `allocator.vtable.alloc(context, size, alignment)` once the remaining argument types are supported. `@mut proc` and `*proc` are invalid; `@mut Callback` instead points to writable callback storage.