hyper-literate/collects/scriblib/private/counter.rkt
Matthew Flatt d438cd4fab add scriblib/footnote library
original commit: 69230100e4859c642f1fa4a1a61ddc6c7a976535
2010-05-21 19:40:33 -06:00

65 lines
2.0 KiB
Racket

#lang scheme
(require scribble/struct
scribble/decode)
(provide new-counter
counter-target
counter-ref
counter-collect-value)
(define-struct counter ([n #:mutable] name))
(define (new-counter name)
(make-counter 0 name))
(define (counter-target counter tag label . content)
(let ([content (decode-content content)])
(make-target-element
#f
(list
(make-collect-element
#f
(list
(make-delayed-element
(lambda (renderer part ri)
(let ([n (resolve-get part ri `(counter (,(counter-name counter) ,tag "value")))])
(let ([l (cons (format "~a" n) content)])
(if label
(list* label 'nbsp l)
l))))
(lambda () (if label
(list* label 'nbsp "N" content)
(cons "N" content)))
(lambda () (if label
(list* label 'nbsp "N" content)
(cons "N" content)))))
(lambda (ci)
(let ([n (add1 (counter-n counter))])
(set-counter-n! counter n)
(collect-put! ci `(counter (,(counter-name counter) ,tag "value")) n)))))
`(counter (,(counter-name counter) ,tag)))))
(define (counter-ref counter tag label)
(let ([n (make-delayed-element
(lambda (renderer part ri)
(let ([n (resolve-get part ri `(counter (,(counter-name counter) ,tag "value")))])
(list (format "~a" n))))
(lambda () (if label
(list label 'nbsp "N")
(list "N")))
(lambda () (if label
(list label 'nbsp "N")
(list "N"))))])
(make-link-element
#f
(if label
(list
label
'nbsp
n)
n)
`(counter (,(counter-name counter) ,tag)))))
(define (counter-collect-value counter)
(counter-n counter))