; code for managing the language-specific backend

(in-package "VERRAZANO")

; represents the state of the backend
(defstruct backend-state
  definitions)

; entry point for backends to add methods to
(defgeneric generate-package (backend def-queue config))

; generate an ordered list of elements to define
(defun generate-definition-queue (ir)
  (let ((state (make-backend-state :definitions nil)))
    (queue-definitions ir state)
    (unmark-graph ir)
    (generated-ordered-queue state)))

; queue up all the definitions in the IR
(defun queue-definitions (ir state)
  (apply-to-nodes #'(lambda (n)
		      (queue-node-definitions n state)) ir '(defines)))

; queue the definitions of a node
(defun queue-node-definitions (node state)
  (apply-to-outgoing #'(lambda (e)
			 (push (list node e (edge-target e))
			       (backend-state-definitions state)))
		     node '(defines)))

; generate an ordered queue of definitions
(defun generated-ordered-queue (state)
  (sort (backend-state-definitions state) #'<
	:key #'(lambda (seqelt)
		 (node-order (caddr seqelt)))))