;; Location ::= Nat | Symbol
;; Source ::= (make-source Location Location)
(define-record-type source :source
  (make-source start stop)
  source?
  (start really-source-start)
  (stop really-source-stop))
 
(define (source-start obj)
  (cond ((element? obj) (element-start obj))
	((attribute? obj) (attribute-start obj))
	((pcdata? obj) (pcdata-start obj))
	((entity? obj) (entity-start obj))
	((pi? obj) (pi-start obj))
	((start-tag? obj) (start-tag-start obj))
	((end-tag? obj) (end-tag-start obj))
	(else (really-source-start obj))))

(define (source-stop obj)
  (cond ((element? obj) (element-stop obj))
	((attribute? obj) (attribute-stop obj))
	((pcdata? obj) (pcdata-stop obj))
	((entity? obj) (entity-stop obj))
	((pi? obj) (pi-stop obj))
	((start-tag? obj) (start-tag-stop obj))
	((end-tag? obj) (end-tag-stop obj))
	(else (really-source-stop obj))))

;; Document ::= (make-document Prolog Element (listof Misc))
(define-record-type document :document
  (make-document prolog element misc)
  document?
  (prolog document-prolog)
  (element document-element)
  (misc document-misc))

;; Prolog ::= (make-prolog (listof Misc) #f)
(define-record-type prolog :prolog
  (make-prolog misc dtd)
  prolog?
  (misc prolog-misc)
  (dtd prolog-dtd))

;; Element ::= (make-element Location Location Symbol (listof Attribute) (listof Content))
(define-record-type element :element
  (make-element start stop name attributes content)
  element?
  (start element-start)
  (stop element-stop)
  (name element-name)
  (attributes element-attributes)
  (content element-content))

;; Attribute ::= (make-attribute Location Location Symbol String)
(define-record-type attribute :attribute
  (make-attribute start stop name value)
  attribute?
  (start attribute-start)
  (stop attribute-stop)
  (name attribute-name)
  (value attribute-value))

;; Pcdata ::= (make-pcdata Location Location String)
(define-record-type pcdata :pcdata
  (make-pcdata start stop string)
  pcdata?
  (start pcdata-start)
  (stop pcdata-stop)
  (string pcdata-string))

;; Content ::= Pcdata  
;;          |  Element
;;          |  Entity
;;          |  Misc

;; Misc ::= Comment
;;       |  Processing-instruction

;; Entity ::= (make-entity Location Location (U Nat Symbol))
(define-record-type entity :entity
  (make-entity start stop text)
  entity?
  (start entity-start)
  (stop entity-stop)
  (text entity-text))

;; Processing-instruction ::= (make-pi Location Location String (list String))
;; also represents XMLDecl
(define-record-type pi :pi
  (make-pi start stop target-name instruction)
  pi?
  (start pi-start)
  (stop pi-stop)
  (target-name pi-target-name)
  (instruction pi-instruction))

;; Comment ::= (make-comment String)
(define-record-type comment :comment
  (make-comment text)
  comment?
  (text comment-text))

;; content? : TST -> Bool
(define (content? x)
  (or (pcdata? x) (element? x) (entity? x) (comment? x) (pi? x)))


;;; moved here from reader as it inherits from source
;; Start-tag ::= (make-start-tag Location Location Symbol (listof Attribute))
(define-record-type start-tag :start-tag
  (make-start-tag start stop name attrs)
  start-tag?
  (start start-tag-start)
  (stop start-tag-stop)
  (name start-tag-name)
  (attrs start-tag-attrs))


;; End-tag ::= (make-end-tag Location Location Symbol)
(define-record-type end-tag :end-tag
  (make-end-tag start stop name)
  end-tag?
  (start end-tag-start)
  (stop end-tag-stop)
  (name end-tag-name))