1 files changed, 125 insertions, 0 deletions
diff --git a/stdlib/source/library/lux/meta/compiler/target/jvm/type/descriptor.lux b/stdlib/source/library/lux/meta/compiler/target/jvm/type/descriptor.lux
new file mode 100644
index 000000000..2327f07b2
--- /dev/null
+++ b/stdlib/source/library/lux/meta/compiler/target/jvm/type/descriptor.lux
@@ -0,0 +1,125 @@
+(.require
+ [library
+  [lux (.except Declaration int char)
+   [abstract
+    [equivalence (.only Equivalence)]]
+   [control
+    ["[0]" maybe]]
+   [data
+    ["[0]" text (.use "[1]#[0]" equivalence)
+     ["%" \\format (.only format)]]
+    [collection
+     ["[0]" list (.use "[1]#[0]" functor)]]]
+   [math
+    [number
+     ["n" nat]]]
+   [meta
+    [type
+     ["[0]" nominal (.except def)]]]]]
+ ["[0]" //
+  [category (.only Void Value Return Method Primitive Object Class Array Var Parameter Declaration)]
+  ["/[1]" //
+   [encoding
+    ["[1][0]" name (.only Internal External)]]]])
+
+(nominal.def .public (Descriptor category)
+  Text
+
+  (def .public descriptor
+    (-> (Descriptor Any) Text)
+    (|>> representation))
+
+  (with_template [<sigil> <category> <name>]
+    [(def .public <name>
+       (Descriptor <category>)
+       (abstraction <sigil>))]
+
+    ["V" Void void]
+    ["Z" Primitive boolean]
+    ["B" Primitive byte]
+    ["S" Primitive short]
+    ["I" Primitive int]
+    ["J" Primitive long]
+    ["F" Primitive float]
+    ["D" Primitive double]
+    ["C" Primitive char]
+    )
+
+  (def .public class_prefix "L")
+  (def .public class_suffix ";")
+
+  (def .public class
+    (-> External (Descriptor Class))
+    (|>> ///name.internal
+         ///name.read
+         (text.enclosed [..class_prefix ..class_suffix])
+         abstraction))
+
+  (def .public (declaration name)
+    (-> External (Descriptor Declaration))
+    (transmutation (..class name)))
+
+  (def .public as_class
+    (-> (Descriptor Declaration) (Descriptor Class))
+    (|>> transmutation))
+
+  (with_template [<name> <category>]
+    [(def .public <name>
+       (Descriptor <category>)
+       (transmutation
+        (..class "java.lang.Object")))]
+
+    [var Var]
+    [wildcard Parameter]
+    )
+
+  (def .public (lower descriptor)
+    (-> (Descriptor Parameter) (Descriptor Parameter))
+    ..wildcard)
+
+  (def .public upper
+    (-> (Descriptor Parameter) (Descriptor Parameter))
+    (|>> transmutation))
+  
+  (def .public array_prefix "[")
+
+  (def .public array
+    (-> (Descriptor Value)
+        (Descriptor Array))
+    (|>> representation
+         (format ..array_prefix)
+         abstraction))
+
+  (def .public (method [inputs output])
+    (-> [(List (Descriptor Value))
+         (Descriptor Return)]
+        (Descriptor Method))
+    (abstraction
+     (format (|> inputs
+                 (list#each ..descriptor)
+                 text.together
+                 (text.enclosed ["(" ")"]))
+             (representation output))))
+
+  (def .public equivalence
+    (All (_ category) (Equivalence (Descriptor category)))
+    (implementation
+     (def (= parameter subject)
+       (text#= (representation parameter) (representation subject)))))
+
+  (def .public class_name
+    (-> (Descriptor Object) Internal)
+    (let [prefix_size (text.size ..class_prefix)
+          suffix_size (text.size ..class_suffix)]
+      (function (_ descriptor)
+        (let [repr (representation descriptor)]
+          (if (text.starts_with? ..array_prefix repr)
+            (///name.internal repr)
+            (|> repr
+                (text.clip prefix_size
+                           (|> (text.size repr)
+                               (n.- prefix_size)
+                               (n.- suffix_size)))
+                (of maybe.monad each ///name.internal)
+                maybe.trusted))))))
+  )