refactor string exceptions

1 files changed, 11 insertions, 9 deletions

diff --git a/mcgoron.iterator.string.scm b/mcgoron.iterator.string.scm
index 762b79d..62f10c4 100644
--- a/mcgoron.iterator.string.scm
+++ b/mcgoron.iterator.string.scm
@@ -76,21 +76,23 @@
         (string-cursor<? x-cur y-cur)))
     #f)))
 
+(define (string-constructor-exception obj)
+  (make-iterator-exception #f
+                           'string-constructor
+                           (list (cons 'obj obj))))
+
 (define-syntax define-for-iterator-or-string
   ;; Define a function such that the first argument can either be a string
   ;; or a string iterator. The string iterator has its string extracted
   ;; before use.
   (syntax-rules ()
     ((_ (name str args ...) body ...)
-     (define (name object args ...)
-       (define (internal str args ...)
-         body ...)
-       (cond
-         ((string? object) (internal object args ...))
-         ((string-iterator? object) (internal (string-iterator-str object)
-                                              args ...))
-         (else (raise (string-iterator-constructor-exception
-                       object))))))))
+     (define (name str args ...)
+       (let ((str (cond
+                    ((string? str) str)
+                    ((string-iterator? str) (string-iterator-str str))
+                    (else (raise (string-constructor-exception str))))))
+         body ...)))))
 
 (define-for-iterator-or-string (string-iterator-start str)
   (string-iterator str (string-cursor-start str)))