code: def _number_slash_end_handler(c, ctx, event):
      
      assert c == _SLASH
      c, self = yield
      next_ctx = ctx.derive_child_context(ctx.whence)
      comment = _comment_handler(_SLASH, next_ctx, next_ctx.whence)
      comment.send((c, comment))
      # If the previous line returns without error, it's a valid comment and the number may be emitted.
      yield _CompositeTransition(event, ctx, comment, next_ctx, initialize_handler=False)
docs: Handles numeric values that end in a forward slash. This is only legal if the slash begins a comment; thus,
      this co-routine either results in an error being raised or an event being yielded.