fix fix printing

Author: Andrew Kent

typed-racket-lib/typed-racket/env/init-envs.rkt

@@ -264,7 +264,9 @@
      `(make-Opaque (quote-syntax ,pred))]
     [(Refinement: parent pred)
      `(make-Refinement ,(type->sexp parent) (quote-syntax ,pred))]
-    [(Mu-name: n b)
+    [(Mu-maybe-name: n (? Type? b))
+     `(make-Mu (quote ,n) ,(type->sexp b))]
+    [(Mu: n b)
      `(make-Mu (quote ,n) ,(type->sexp b))]
     [(Poly-names: ns b)
      `(make-Poly (list ,@(for/list ([n (in-list ns)])

typed-racket-lib/typed-racket/rep/type-rep.rkt

@@ -32,7 +32,7 @@
                                    "base-union.rkt")
                      Type Prop Object PathElem SomeValues)
          Type?
-         Mu-name:
+         Mu-maybe-name:
          Poly-names: Poly-fresh:
          PolyDots-names:
          PolyRow-names: PolyRow-fresh:
@@ -1522,13 +1522,15 @@
                                (list sym (Mu-body* sym t))))
                  (list np bp)))])))
 
-(define-match-expander Mu-name:
+(define-match-expander Mu-maybe-name:
   (lambda (stx)
     (syntax-case stx ()
       [(_ np bp)
        #'(? Mu?
-            (app (lambda (t) (let ([sym (hash-ref type-var-name-table t (lambda _ (gensym)))])
-                               (list sym (Mu-body* sym t))))
+            (app (lambda (t) (let ([sym (hash-ref type-var-name-table t #f)])
+                               (if sym
+                                   (list sym (Mu-body* sym t))
+                                   (list #f #f))))
                  (list np bp)))])))
 
 ;; These match expanders correspond to opening up a type in

typed-racket-lib/typed-racket/types/printer.rkt

@@ -686,6 +686,8 @@
                       #t]
                      [_ #f])))
      'Syntax]
+    [(Mu-maybe-name: name (? Type? body))
+     `(Rec ,name ,(t->s body))]
     [(Mu-unsafe: raw-body)
      (with-printable-names 1 name-ids
        (let ([names (for/list ([id (in-list name-ids)])
@@ -717,7 +719,8 @@
      name]
     [(DepFun: raw-dom raw-pre raw-rng)
      (with-printable-names (length raw-dom) ids
-       (define dom (instantiate-obj raw-dom ids))
+       (define dom (for/list ([d (in-list raw-dom)])
+                     (instantiate-obj d ids)))
        (define pre (instantiate-obj raw-pre ids))
        (define rng (instantiate-obj raw-rng ids))
        (define (arg-id? id) (member id ids free-identifier=?))