Avoid overlap with sequences of the wrong arity.

Fixes #371.

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

@@ -69,6 +69,17 @@
                                         (overlap? b b*))]
       ;; lots of things are sequences, but not values where sequence? produces #f
       [((Sequence: _) (Value: v)) #:no-order (sequence? v)]
+      ;; hash tables are two-valued sequences
+      [((Sequence: (or (list _) (list _ _ _ ...)))
+        (or (? Hashtable?) (? HashtableTop?)))
+        #:no-order
+        #f]
+      ;; these are single-valued sequences
+      [((Sequence: (list _ _ _ ...))
+        (or (? Pair?) (? Vector?) (? VectorTop?)))
+        #:no-order
+        #f]
+      ;; be conservative about other kinds of sequences
       [((Sequence: _) _) #:no-order #t]
       ;; Values where evt? produces #f cannot be Evt
       [((Evt: _) (Value: v)) #:no-order (evt? v)]

typed-racket-test/main.rkt

@@ -172,7 +172,7 @@
          int-tests unit-tests compile-benchmarks compile-math
          optimization-tests missed-optimization-tests)
 
-(module+ main
+;(module+ main
   (require racket/vector racket/gui/dynamic rackunit racket/cmdline)
 
   (define exec (make-parameter go/text))
@@ -185,6 +185,7 @@
   (define math? (make-parameter #f))
   (define single (make-parameter #f))
   (current-namespace (make-base-namespace))
+  (printf "~a" (current-command-line-arguments))
   (command-line
    #:once-each
    ["-v" "verbose" (verbose? #t)]
@@ -221,7 +222,7 @@
                                     (if (math?)       (list (compile-math))              '())))])])
         (unless (= 0 ((exec) to-run))
           (eprintf "Typed Racket Tests did not pass.\n")
-          (exit 1)))))
+          (exit 1))));)
 
 ;; nightly tests in `run.rkt` for drdr chart continuity
 (module test racket/base)