monads: Fix 'liftN' fallback case.

Reported by Andy Wingo <wingo@igalia.com>.

* guix/monads.scm (define-lift) <fallback case>: Add missing #'.  Remove
  extra formal parameter.
* tests/monads.scm ("lift"): Add test with 'lift1' as a procedure.

1 files changed, 3 insertions, 1 deletions

diff --git a/tests/monads.scm b/tests/monads.scm
index d3ef065f24..62a07a2bc6 100644
--- a/tests/monads.scm
+++ b/tests/monads.scm
@@ -95,10 +95,12 @@
 
 (test-assert "lift"
   (every (lambda (monad run)
-           (let ((f (lift1 1+ monad)))
+           (let ((f (lift1 1+ monad))
+                 (g (apply lift1 1+ (list monad))))
              (with-monad monad
                (let ((number (random 777)))
                  (= (run (>>= (return number) f))
+                    (run (>>= (return number) g))
                     (1+ number))))))
          %monads
          %monad-run))