+ /* Reset read_buf for scm_ftell.
+ Shouldn't scm_read () do this for us? */
+ scm_fill_input (port);
+ SCM to = scm_ftell (port);
+ ps->nchars = scm_to_int (to) - scm_to_int (from);
+
+
+ /* Read expression from port. */
+ if (!SCM_EOF_OBJECT_P (form))