Add INDEX matcher since that's so common.

diff --git a/src/runtime/syntax-check.scm b/src/runtime/syntax-check.scm
index bf59fbe7be819ae18d5f87c377a873468bae29ef..25c81db0858182d18b5cfc4d5043971566cab555 100644 (file)
--- a/src/runtime/syntax-check.scm
+++ b/src/runtime/syntax-check.scm
@@ -51,6 +51,7 @@ USA.
             ((STRING) (string? object))
             ((CHAR) (char? object))
             ((URI) (->uri object #f))
+            ((INDEX) (exact-nonnegative-integer? object))
             (else (match-error))))
          ((pair? pattern)
           (case (car pattern)