Change subexpression marker to not require quoting.

diff --git a/src/runtime/debug.scm b/src/runtime/debug.scm
index d85fa1ef9a7ee36ba428757facacf7fb3c499148..ee9830887afcd2d465de7d5d88e10f0aa9ef84a7 100644 (file)
--- a/src/runtime/debug.scm
+++ b/src/runtime/debug.scm
@@ -360,8 +360,7 @@ USA.
           (newline port)
           (write (stack-frame/return-address subproblem) port)))))
 
-(define subexpression-marker
-  ((ucode-primitive string->symbol) "###"))
+(define-integrable subexpression-marker '<!>)
 
 (define (print-subproblem-environment dstate port)
   (let ((environment-list (dstate/environment-list dstate)))