cl-scopes/core/core.lisp

119 lines
3.4 KiB
Common Lisp

;;;; cl-scopes/core - here comes the real action
(defpackage :scopes/core
(:use :common-lisp)
(:local-nicknames (:config :scopes/config)
(:message :scopes/core/message)
(:shape :scopes/shape)
(:alx :alexandria))
(:export #:*root* #:default-setup #:default-actions
#:find-service #:setup-services
#:context #:add-action #:config #:name #:send #:shutdown
#:handle-message
#:do-print #:echo))
(in-package :scopes/core)
;;;; actions
(defclass action-spec ()
((pattern :reader pattern :initarg :pattern :initform nil)
(handlers :accessor handlers :initarg :handlers)))
(defun select (msg acts)
(let ((h (shape:head msg))
(hdlrs nil))
(dolist (a acts)
(if (match (pattern a) h)
(dolist (hdlr (handlers a))
(push hdlr hdlrs))))
hdlrs))
;(nreverse hdlrs)))
(defun match (pat h)
(dolist (item pat)
(if (and item (not (eq item (pop h))))
(return-from match nil)))
t)
(defun find-action (pat acts)
(dolist (a acts)
(if (equal (pattern a) pat)
(return-from find-action a))))
;;;; context
(defvar *root* nil)
(defclass context ()
((config :reader config :initarg :config)
(name :reader name :initarg :name)
(actions :accessor actions :initform nil)
(default-actions :reader default-actions :initform nil)
(services :reader services :initform (make-hash-table))))
(defun default-setup (cfg &optional (cls 'context))
(make-instance cls :config cfg :name (config:name cfg)))
(defun find-service (name &optional (parent *root*))
(with-slots (services) parent
(when services
(gethash name services))))
(defun setup-services (&optional (cfg config:*root*))
(setf *root* (make-instance 'context :config cfg))
(dolist (c (reverse (config:children cfg)))
(add-service *root* c)))
(defun shutdown ()
(dolist (ctx (alx:hash-table-values (services *root*)))
(funcall (config:shutdown (config ctx)) ctx)))
(defun add-action (ctx pat hdlr)
(let* ((acts (actions ctx))
(act (find-action pat acts)))
(if act
(push hdlr (handlers act))
(push (make-instance 'action-spec :pattern pat :handlers (list hdlr))
(actions ctx)))))
(defun add-service (ctx cfg)
(with-slots (services) ctx
(let ((child (funcall (config:setup cfg) cfg)))
(when child
(dolist (a (config:actions cfg))
(add-action child (car a) (cadr a)))
(setf (gethash (config:name cfg) services) child)))))
(defgeneric send (rcvr msg)
(:method ((rcvr context) msg)
(handle-message rcvr msg)))
(defgeneric handle-message (ctx msg)
(:method ((ctx context) msg)
(cond
((do-actions ctx msg) t)
((do-actions ctx msg #'default-actions) t)
(t (log:warn "no action selected for ~s" msg)))))
(defun do-actions (ctx msg &optional (acts #'actions))
(let ((hdlrs (select msg (funcall acts ctx))))
(when hdlrs
(dolist (hdlr hdlrs)
(funcall hdlr ctx msg))
t)))
;;;; some simple predefined actions
(defun echo (ctx msg)
(let ((sndr (message:sender msg)))
(if sndr
(let* ((h (shape:head msg))
(new-msg (message:create `(:scopes :echo ,@(cddr h))
:data (shape:data msg))))
(send sndr new-msg))
(log:warn "sender missing: ~s" msg))))
(defun do-print (ctx msg)
(declare (ignore ctx))
(format t "~&~s~%" msg))