Don't refactor quasiquotes with only literals (#474)

Closes #425.

Author: jackfirth

default-recommendations/list-shortcuts-test.rkt

@@ -139,6 +139,10 @@ test: "unnecessary quasiquotation with constants refactorable to list"
 ------------------------------
 
 
+test: "quasiquotation with only constants not refactorable to list"
+- `(1 2 3)
+
+
 test: "unnecessary splicing quasiquotation refactorable to append"
 ------------------------------
 (define (f xs ys zs)

default-recommendations/list-shortcuts.rkt

@@ -106,16 +106,18 @@
 
 
 (define-syntax-class unquoted
-  #:attributes (expr)
+  #:attributes (expr literal?)
   #:literals (unquote)
-  (pattern expr:literal-constant)
-  (pattern (unquote expr)))
+  (pattern expr:literal-constant #:attr literal? #true)
+  (pattern (unquote expr) #:attr literal? #false))
 
 
 (define-refactoring-rule quasiquote-to-list
   #:description "This quasiquotation is equialent to a simple `list` call."
   #:literals (quasiquote)
   (quasiquote (arg:unquoted ...))
+  #:when (for/or ([literal? (in-list (attribute arg.literal?))])
+           (not literal?))
   (list arg.expr ...))