fix lexer contract

collects/syntax-color/lexer-contract.rkt

@@ -3,6 +3,16 @@
          unstable/options)
 (provide lexer/c)
 
+(define (end/c start type)
+  (cond
+    [(equal? 'eof type) 
+     (or/c exact-positive-integer? #f)]
+    [start
+     (and/c exact-positive-integer?
+            (>/c start))]
+    [else
+     #f]))
+
 (define lexer/c
   (option/c
    (or/c (->i ([in (and/c input-port? port-counts-lines?)])
@@ -10,11 +20,7 @@
                       [type symbol?]
                       [paren (or/c symbol? #f)]
                       [start (or/c exact-positive-integer? #f)]
-                      [end (start) 
+                      [end (start type) (end/c start type)]))
-                           (if start
-                               (and/c exact-positive-integer?
-                                      (>=/c start))
-                               #f)]))
          (->i ([in (and/c input-port? port-counts-lines?)]
                [offset exact-nonnegative-integer?]
                [mode any/c])
@@ -22,11 +28,7 @@
                       [type symbol?]
                       [paren (or/c symbol? #f)]
                       [start (or/c exact-positive-integer? #f)]
-                      [end (start) 
+                      [end (start type) (end/c start type)]
-                           (if start
-                               (and/c exact-positive-integer?
-                                      (>=/c start))
-                               #f)]
                       [backup exact-nonnegative-integer?]
                       [new-mode any/c])))
    #:tester (λ (x) (and (procedure? x) 

collects/syntax-color/racket-lexer.rkt

@@ -7,9 +7,9 @@
   
   (provide 
    (contract-out
-    [racket-lexer lexer/c]
+    [racket-lexer lexer/c])
-    [racket-lexer/status lexer/c]
+   racket-lexer/status
-    [racket-nobar-lexer/status lexer/c]))
+   racket-nobar-lexer/status)
    
   (define-lex-abbrevs