Index: tool/lemon.c
==================================================================
--- tool/lemon.c
+++ tool/lemon.c
@@ -3410,10 +3410,14 @@
     j = 0;
     while( isspace(*cp) ) cp++;
     while( *cp ) stddt[j++] = *cp++;
     while( j>0 && isspace(stddt[j-1]) ) j--;
     stddt[j] = 0;
+    if( strcmp(stddt, lemp->tokentype)==0 ){
+      sp->dtnum = 0;
+      continue;
+    }
     hash = 0;
     for(j=0; stddt[j]; j++){
       hash = hash*53 + stddt[j];
     }
     hash = (hash & 0x7fffffff)%arraysize;