feat: evaluate compile-time scalar procedure calls

README.md

@@ -96,7 +96,9 @@ 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. runtime values and mutable bindings cannot supply compile-time arguments. runaway specialization is diagnosed at 128 nested evaluation/specialization calls or 4096 instances. arbitrary compile-time procedure execution, reflection, `inline` iteration and full generic standard-library compilation remain outside this checkpoint.
+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.
 
 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.