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

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

;;;;;;
;;; Projection

(def (projection e) sequential ()
  ((elements :type list)))

;;;;;;
;;; Construction

(def (function e) make-projection/sequential (projections)
  (make-projection 'sequential :elements projections))

;;;;;;
;;; Construction

(def (macro e) sequential (&body forms)
  `(make-projection/sequential (list ,@forms)))

;;;;;;
;;; Printer

(def printer sequential (projection recursion input input-reference output-reference)
  (iter (for output :initially input :then (output-of iomap))
        (for index :from 0)
        (for element :in (elements-of projection))
        ;; TODO: how do we handle input output references here? what is forward here?
        (for element-input-reference :initially input-reference :then `(forward ,element-input-reference))
        (for element-output-reference = `(forward ,element-input-reference))
        ;; TODO: KLUDGE: properly recurse with iomap
        (for iomap = (bind ((*iomap* (if *iomap*
                                         (make-iomap/recursive input output (list *iomap* (make-iomap/sequential input output element-iomaps)))
                                         (make-iomap/sequential input output element-iomaps))))
                       (funcall (printer-of element) element recursion output element-input-reference
                                (if (= index (1- (length (elements-of projection))))
                                    output-reference
                                    element-output-reference))))
        (collect iomap :into element-iomaps)
        (finally (return (make-iomap/sequential input output element-iomaps)))))

;;;;;;
;;; Reader

(def reader sequential (projection recursion input input-reference output-reference)
  ;; KLUDGE:
  (iter (for output :initially input :then (or xxx input))
        (for index :from 0)
        (for element :in (reverse (elements-of projection)))
        (for xxx = (funcall (reader-of element) element recursion output input-reference output-reference))
        (finally (return xxx))))