[hunchentoot-devel] Subclassing ACCEPTOR

[Hans Hübner]

Sebastian,

the acceptor class has a :default-initargs clause, so the :initform
that you've provided is never being looked at.  Use a
:default-initargs in your vhost class to override the inherited :name
initarg.

-Hans

On Mon, Dec 12, 2011 at 3:07 PM, Sebastian Tennant
<sebyte at smolny.plus.com> wrote:
> Hi list,
>
>  (make-package :vhost :use '(:common-lisp))
>  ;;; => #<PACKAGE "VHOST">
>
>  (in-package :vhost)
>
>  (defclass vhost (tbnl:acceptor)
>   ((tbnl::name
>     :initform
>     (error "Please give this VHOST a meaningful name."))))
>  ;;; => #<STANDARD-CLASS VHOST>
>
>  (describe 'vhost)
>  ;;; => VHOST::VHOST
>  ;;;      [symbol]
>  ;;;
>  ;;;    VHOST names the standard-class #<STANDARD-CLASS VHOST>:
>  ;;;      Class precedence-list: VHOST, HUNCHENTOOT:ACCEPTOR, STANDARD-OBJECT,
>  ;;;                             SB-PCL::SLOT-OBJECT, T
>  ;;;      Direct superclasses: HUNCHENTOOT:ACCEPTOR
>  ;;;      No subclasses.
>  ;;;      Direct slots:
>  ;;;        HUNCHENTOOT::NAME
>  ;;;          Initform: (ERROR "A virtual host must have a meaningful name.")
>
>  (defvar *vhost1* (make-instance 'vhost))
>  ;;; => *VHOST1*                                 <--- WHY NO ERROR ???
>
>  (describe *vhost1*)
>  ;;; => #<VHOST (host *, port 80)>
>  ;;;      [standard-object]
>  ;;;
>  ;;;    Slots with :INSTANCE allocation:
>  ;;;      PORT                      = 80
>  ;;;      ADDRESS                   = NIL
>  ;;;      NAME                      = #:G1150    <--- this is what I want to prevent
>  ;;;    [...]
>
> Practical Common Lisp - page 214:
>
>  "... if multiple classes specify an initform the new class uses the one from
>  the most specific class.  This allows a subclass to specify a different
>  default value than the one it would otherwise inherit."
>
> What am I doing wrong here?
>
> Sebastian
> --
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>
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