runtime: mint type identity — TypeValue/MintId + unified eq (BEP-066 s1, PR 4)

baml_language/crates/baml_builtins2/baml_std/baml/ns_reflect/ns_array/array.baml

@@ -0,0 +1,9 @@
+/// An array-kind view of a `type` value. Users never construct this class.
+class Type {
+  implements baml.reflect.TypeView {
+    //baml:vm
+    function as_type(self) -> type throws never { $rust_function }
+  }
+  //baml:mut_vm
+  function element_type(self) -> type throws never { $rust_function }
+}

baml_language/crates/baml_builtins2/baml_std/baml/ns_reflect/ns_class/class.baml

@@ -0,0 +1,17 @@
+class Field {
+  name string
+  type type?
+  meta baml.reflect.Meta
+}
+
+/// A class-kind view of a `type` value. Users never construct this class.
+class Type {
+  implements baml.reflect.TypeView {
+    //baml:vm
+    function as_type(self) -> type throws never { $rust_function }
+  }
+  //baml:mut_vm
+  function fields(self) -> Field[] throws never { $rust_function }
+  //baml:mut_vm
+  function meta(self) -> baml.reflect.Meta throws never { $rust_function }
+}

baml_language/crates/baml_builtins2/baml_std/baml/ns_reflect/ns_enum/enum.baml

@@ -0,0 +1,16 @@
+class Value {
+  name string
+  meta baml.reflect.Meta
+}
+
+/// An enum-kind view of a `type` value. Users never construct this class.
+class Type {
+  implements baml.reflect.TypeView {
+    //baml:vm
+    function as_type(self) -> type throws never { $rust_function }
+  }
+  //baml:mut_vm
+  function values(self) -> Value[] throws never { $rust_function }
+  //baml:mut_vm
+  function meta(self) -> baml.reflect.Meta throws never { $rust_function }
+}

baml_language/crates/baml_builtins2/baml_std/baml/ns_reflect/ns_function/function.baml

@@ -0,0 +1,18 @@
+class Parameter {
+  name string?
+  type type
+  optional bool
+}
+
+/// A function-kind view of a `type` value. Throws are intentionally not part
+/// of the slice-1 reflection surface.
+class Type {
+  implements baml.reflect.TypeView {
+    //baml:vm
+    function as_type(self) -> type throws never { $rust_function }
+  }
+  //baml:mut_vm
+  function params(self) -> Parameter[] throws never { $rust_function }
+  //baml:mut_vm
+  function return_type(self) -> type throws never { $rust_function }
+}

baml_language/crates/baml_builtins2/baml_std/baml/ns_reflect/ns_interface/interface.baml

@@ -0,0 +1,11 @@
+/// An interface-kind view of a `type` value. Users never construct this class.
+class Type {
+  implements baml.reflect.TypeView {
+    //baml:vm
+    function as_type(self) -> type throws never { $rust_function }
+  }
+  //baml:vm
+  function implemented_by(self, other: type) -> bool throws never { $rust_function }
+  //baml:mut_vm
+  function implementors(self) -> type[] throws never { $rust_function }
+}

baml_language/crates/baml_builtins2/baml_std/baml/ns_reflect/ns_literal/literal.baml

@@ -0,0 +1,7 @@
+/// A literal-kind view of a `type` value. Users never construct this class.
+class Type {
+  implements baml.reflect.TypeView {
+    //baml:vm
+    function as_type(self) -> type throws never { $rust_function }
+  }
+}

baml_language/crates/baml_builtins2/baml_std/baml/ns_reflect/ns_map/map.baml

@@ -0,0 +1,11 @@
+/// A map-kind view of a `type` value. Users never construct this class.
+class Type {
+  implements baml.reflect.TypeView {
+    //baml:vm
+    function as_type(self) -> type throws never { $rust_function }
+  }
+  //baml:mut_vm
+  function key_type(self) -> type throws never { $rust_function }
+  //baml:mut_vm
+  function value_type(self) -> type throws never { $rust_function }
+}

baml_language/crates/baml_builtins2/baml_std/baml/ns_reflect/ns_primitive/primitive.baml

@@ -0,0 +1,7 @@
+/// A primitive-kind view of a `type` value. Users never construct this class.
+class Type {
+  implements baml.reflect.TypeView {
+    //baml:vm
+    function as_type(self) -> type throws never { $rust_function }
+  }
+}

baml_language/crates/baml_builtins2/baml_std/baml/ns_reflect/ns_union/union.baml

@@ -0,0 +1,9 @@
+/// A union-kind view of a `type` value. Users never construct this class.
+class Type {
+  implements baml.reflect.TypeView {
+    //baml:vm
+    function as_type(self) -> type throws never { $rust_function }
+  }
+  //baml:mut_vm
+  function member_types(self) -> type[] throws never { $rust_function }
+}

baml_language/crates/baml_builtins2/baml_std/baml/ns_reflect/reflect.baml

@@ -10,6 +10,22 @@ class Arg {
   type type
 }
 
+/// Metadata baked into reflected schema definitions.
+class Meta {
+  alias string?
+  description string?
+  docstring string?
+  other map<string, string>
+}
+
+/// Common identity-preserving surface shared by every reflection kind view.
+interface TypeView {
+  function as_type(self) -> type throws never
+}
+
+/// The closed set of reflection views for a runtime `type` value.
+type TypeKind = baml.reflect.class.Type | baml.reflect.enum.Type | baml.reflect.union.Type | baml.reflect.literal.Type | baml.reflect.array.Type | baml.reflect.map.Type | baml.reflect.interface.Type | baml.reflect.primitive.Type | baml.reflect.function.Type
+
 /// The runtime signature of a function value, reconstructed from the value
 /// itself (BEP-062). Positional (required) parameters appear in `args` in
 /// declaration order; named/optional parameters appear in `opts`, keyed by

baml_language/crates/baml_builtins2/baml_std/baml/type_class.baml

@@ -7,6 +7,32 @@
 /// Users never construct `Type` directly; they receive `type` values via
 /// `type.of<User>()` and call methods on them.
 class TypeValue {
+    /// Returns the precise kind view of this type value. The view preserves
+    /// the receiver's mint identity.
+    //baml:vm
+    function kind(self) -> baml.reflect.TypeKind throws never {
+        $rust_function
+    }
+
+    //baml:vm
+    function as_class(self) -> baml.reflect.class.Type? throws never { $rust_function }
+    //baml:vm
+    function as_enum(self) -> baml.reflect.enum.Type? throws never { $rust_function }
+    //baml:vm
+    function as_union(self) -> baml.reflect.union.Type? throws never { $rust_function }
+    //baml:vm
+    function as_literal(self) -> baml.reflect.literal.Type? throws never { $rust_function }
+    //baml:vm
+    function as_array(self) -> baml.reflect.array.Type? throws never { $rust_function }
+    //baml:vm
+    function as_map(self) -> baml.reflect.map.Type? throws never { $rust_function }
+    //baml:vm
+    function as_interface(self) -> baml.reflect.interface.Type? throws never { $rust_function }
+    //baml:vm
+    function as_primitive(self) -> baml.reflect.primitive.Type? throws never { $rust_function }
+    //baml:vm
+    function as_function(self) -> baml.reflect.function.Type? throws never { $rust_function }
+
     /// Returns the type name as a human-readable string.
     implements baml.ToString {
         function to_string(self) -> string throws never {

baml_language/crates/baml_builtins2/src/lib.rs

@@ -140,6 +140,15 @@ pub const ALL: &[BuiltinFile] = &[
     builtin!("baml", "ns_random/random.baml"),
     // `baml.reflect` (BEP-066 I-9: `reflect` is a keyword shorthand for it).
     builtin!("baml", "ns_reflect/reflect.baml"),
+    builtin!("baml", "ns_reflect/ns_class/class.baml"),
+    builtin!("baml", "ns_reflect/ns_enum/enum.baml"),
+    builtin!("baml", "ns_reflect/ns_union/union.baml"),
+    builtin!("baml", "ns_reflect/ns_literal/literal.baml"),
+    builtin!("baml", "ns_reflect/ns_array/array.baml"),
+    builtin!("baml", "ns_reflect/ns_map/map.baml"),
+    builtin!("baml", "ns_reflect/ns_interface/interface.baml"),
+    builtin!("baml", "ns_reflect/ns_primitive/primitive.baml"),
+    builtin!("baml", "ns_reflect/ns_function/function.baml"),
     // `baml.type` (BEP-066 K-13: `type.of` / `type.of_value` resolve here).
     builtin!("baml", "ns_type/type.baml"),
     // --- boundary package ---