floats iter 1.2: register Float as a primitive type name

crates/ailang-core/src/primitives.rs

@@ -14,7 +14,7 @@
 /// typecheck-time well-formedness gating, the heap-type filter,
 /// the local-type qualifier, and the codegen substitution path.
 pub fn is_primitive_name(name: &str) -> bool {
-    matches!(name, "Int" | "Bool" | "Str" | "Unit")
+    matches!(name, "Int" | "Bool" | "Str" | "Unit" | "Float")
 }
 
 /// Returns the static-lifetime surface name iff `name` is a
@@ -27,6 +27,7 @@ pub fn primitive_surface_name(name: &str) -> Option<&'static str> {
         "Bool" => Some("Bool"),
         "Str" => Some("Str"),
         "Unit" => Some("Unit"),
+        "Float" => Some("Float"),
         _ => None,
     }
 }
@@ -41,12 +42,19 @@ mod tests {
     /// inside both functions plus a sample non-primitive.
     #[test]
     fn predicate_and_surface_name_agree() {
-        for name in ["Int", "Bool", "Str", "Unit", "List", "Foo", "", "int"] {
+        for name in ["Int", "Bool", "Str", "Unit", "Float", "List", "Foo", "", "int"] {
             assert_eq!(
                 is_primitive_name(name),
                 primitive_surface_name(name).is_some(),
                 "lockstep violation for {name:?}"
             );
         }
+        // Float is a primitive (Floats milestone, iter 1).
+        assert!(is_primitive_name("Float"), "Float must be a primitive");
+        assert_eq!(
+            primitive_surface_name("Float"),
+            Some("Float"),
+            "Float surface name must be \"Float\""
+        );
     }
 }