1 files changed, 39 insertions, 0 deletions
diff --git a/stdlib/source/lux/type/dynamic.lux b/stdlib/source/lux/type/dynamic.lux
new file mode 100644
index 000000000..d57669213
--- /dev/null
+++ b/stdlib/source/lux/type/dynamic.lux
@@ -0,0 +1,39 @@
+(.module:
+  [lux #*
+   [control
+    ["ex" exception (#+ exception:)]]
+   [data
+    ["." error]
+    [text
+     format]]
+   [macro (#+ with-gensyms)
+    ["." syntax (#+ syntax:)]]
+   ["." type
+    abstract]])
+
+(exception: #export (wrong-type {expected Type} {actual Type})
+  (ex.report ["Expected" (%type expected)]
+             ["Actual" (%type actual)]))
+
+(abstract: #export Dynamic
+  {}
+
+  [Type Any]
+
+  (def: dynamic-abstraction (-> [Type Any] Dynamic) (|>> :abstraction))
+  (def: dynamic-representation (-> Dynamic [Type Any]) (|>> :representation))
+
+  (syntax: #export (:dynamic value)
+    (with-gensyms [g!value]
+      (wrap (list (` (let [(~ g!value) (~ value)]
+                       ((~! ..dynamic-abstraction) [(:of (~ g!value)) (~ g!value)])))))))
+
+  (syntax: #export (:check type value)
+    (with-gensyms [g!type g!value]
+      (wrap (list (` (let [[(~ g!type) (~ g!value)] ((~! ..dynamic-representation) (~ value))]
+                       (: ((~! error.Error) (~ type))
+                          (if (:: (~! type.Equivalence<Type>) (~' =)
+                                  (.type (~ type)) (~ g!type))
+                            (#error.Success (:coerce (~ type) (~ g!value)))
+                            ((~! ex.throw) ..wrong-type [(.type (~ type)) (~ g!type)])))))))))
+  )