;;; -*- mode: Lisp; Syntax: Common-Lisp; -*-
;;;
;;; Copyright (c) 2009 by the authors.
;;;
;;; See LICENCE for details.

(in-package :hu.dwim.projectional-editor)

;;;;;;
;;; API

(def (generic e) document? (object)
  (:documentation "Returns TRUE if OBJECT is a document, otherwise returns FALSE. Purely functional."))

(def (generic e) print-document (document &optional stream)
  (:documentation "Prints the content of DOCUMENT to STREAM. Has side effects on STREAM."))

(def (generic e) make-projection/t->string (content)
  (:documentation "Returns a new projection object that projects CONTENT to string."))

;;;;;;
;;; Data structure

(def class* document ()
  ((content :type t)
   (selection :type selection)))

;;;;;;
;;; Construction

(def (function e) make-document (content &key selection)
  (make-instance 'document
                 :content content
                 :selection selection))

;;;;;;
;;; Construction

(def (macro e) document ((&key selection) &body content)
  `(make-document ,(first content) :selection ,selection))

;;;;;;
;;; API implementation

(def method document? (object)
  (typep object 'document))

(def method print-document (document &optional (stream *standard-output*))
  (princ (content-of (project-document document (make-projection/t->string (content-of document)))) stream)
  document)