- Fixed a bug with struct auto selection (couldn't handle mixes of vars and expressions).

- Added a test of whether the "Functor::map" function can be auto-selected.

2 files changed, 19 insertions, 11 deletions

diff --git a/stdlib/source/lux/type/auto.lux b/stdlib/source/lux/type/auto.lux
index 31439af3d..aa7074d4a 100644
--- a/stdlib/source/lux/type/auto.lux
+++ b/stdlib/source/lux/type/auto.lux
@@ -235,10 +235,10 @@
   (list l r))
 
 (syntax: #export (::: [member s;symbol]
-                      [args (s;alt (s;some s;symbol)
-                                   (s;some s;any))])
+                      [args (s;alt (s;seq (s;some s;symbol) s;end)
+                                   (s;seq (s;some s;any) s;end))])
   (case args
-    (#;Left args)
+    (#;Left [args _])
     (do @
       [[member-idx sig-type] (resolve-member member)
        input-types (mapM @ resolve-type args)
@@ -260,11 +260,11 @@
                                    (text;join-with ", ")
                                    )))))
 
-    (#;Right args)
+    (#;Right [args _])
     (do @
-      [#let [args-to-bind (list;filter (bool;complement var?) args)]
-       labels (seqM @ (list;repeat (list;size args-to-bind)
+      [labels (seqM @ (list;repeat (list;size args)
                                    (compiler;gensym "")))
-       #let [retry (` (let [(~@ (|> (list;zip2 labels args-to-bind) (List/map join-pair) List/join))]
+       #let [retry (` (let [(~@ (|> (list;zip2 labels args) (List/map join-pair) List/join))]
                         (;;::: (~ (ast;symbol member)) (~@ labels))))]]
-      (wrap (list retry)))))
+      (wrap (list retry)))
+    ))
diff --git a/stdlib/test/test/lux/type/auto.lux b/stdlib/test/test/lux/type/auto.lux
index eb25a2371..cb58514bf 100644
--- a/stdlib/test/test/lux/type/auto.lux
+++ b/stdlib/test/test/lux/type/auto.lux
@@ -7,6 +7,7 @@
   lux
   (lux (codata [io])
        (control monad
+                functor
                 [eq])
        (data [text "Text/" Monoid<Text>]
              text/format
@@ -23,6 +24,13 @@
 (test: "Automatic structure selection"
   [x R;nat
    y R;nat]
-  (assert "Can automatically select first-order structures."
-          (B/= (:: number;Eq<Nat> = x y)
-               (::: = x y))))
+  ($_ seq
+      (assert "Can automatically select first-order structures."
+              (let [(^open "L/") (list;Eq<List> number;Eq<Nat>)]
+                (and (B/= (:: number;Eq<Nat> = x y)
+                          (::: = x y))
+                     (L/= (list;n.range +1 +10)
+                          (::: map n.inc (list;n.range +0 +9)))
+                     )))
+
+      ))