racket/collects/meta/web/www/code.rkt
2011-12-31 14:24:41 -05:00

137 lines
6.6 KiB
Racket

#lang meta/web
(require syntax-color/module-lexer setup/xref scribble/xref)
(provide code)
(define doc-root "http://docs.racket-lang.org/")
(define expand-namespace (make-base-namespace))
(define xref (load-collections-xref))
(define (code . strs)
(let* ([str (apply string-append strs)]
[str (let ([N (- 6 (length (regexp-match-positions* "\n" str)))])
(cond [(N . > . 0)
(string-append str (make-string N #\newline))]
[(N . < . 0)
(error 'code "too many lines in example: ~e" str)]
[else str]))]
[bstr (string->bytes/utf-8 (regexp-replace* #rx"(?m:^$)" str "\xA0"))]
[in (open-input-bytes bstr)]
[tokens
(let loop ([mode #f])
(let-values ([(lexeme type data start end backup-delta mode)
(module-lexer in 0 mode)])
(if (eof-object? lexeme)
null
(cons (list type (sub1 start) (sub1 end) 0)
(loop mode)))))]
[substring* (λ (bstr start [end (bytes-length bstr)])
(bytes->string/utf-8 (subbytes bstr start end)))]
[e (parameterize ([read-accept-reader #t]
[current-namespace expand-namespace])
(expand (read-syntax 'prog (open-input-bytes bstr))))]
[ids (let loop ([e e])
(cond
[(and (identifier? e)
(syntax-original? e))
(let* ([pos (sub1 (syntax-position e))]
[b (identifier-binding e)]
[imp? (and (list? b)
(let-values ([(name base)
(module-path-index-split
(car b))])
(or name base)))]
[tag (and imp?
(xref-binding->definition-tag xref e 0))])
(list (list (if imp?
(if tag
(cons (if (eq? (car tag) 'form)
'linkimportform
'linkimportid)
(let-values ([(p a)
(xref-tag->path+anchor
xref tag
#:external-root-url
doc-root)])
(if a (format "~a#~a" p a) p)))
'importid)
'id)
pos (+ pos (syntax-span e)) 1)))]
[(syntax? e)
(append (loop (syntax-e e))
(loop (or (syntax-property e 'origin)
null))
(loop (or (syntax-property e 'disappeared-use)
null)))]
[(pair? e) (append (loop (car e)) (loop (cdr e)))]
[else null]))]
[link-mod (λ (mp-stx priority #:orig? [always-orig? #f])
(if (or always-orig?
(syntax-original? mp-stx))
(let ([mp (syntax->datum mp-stx)])
(let-values ([(p a)
(xref-tag->path+anchor
xref
`(mod-path ,(format "~s" mp))
#:external-root-url doc-root)])
(if p
(list (let ([pos (sub1 (syntax-position mp-stx))])
(list (cons 'modpath
(if a (format "~a#~a" p a) p))
pos
(+ pos (syntax-span mp-stx))
priority)))
null)))
null))]
[mods (let loop ([e e])
(syntax-case e (module require begin)
[(module name lang (mod-beg form ...))
(apply append
(link-mod #'lang 2)
(map loop (syntax->list #'(form ...))))]
[(#%require spec ...)
(apply append
(map (λ (spec)
;; Need to add support for renaming forms, etc.:
(if (module-path? (syntax->datum spec))
(link-mod spec 2)
null))
(syntax->list #'(spec ...))))]
[(begin form ...)
(append-map loop (syntax->list #'(form ...)))]
[else null]))]
[language (let ([m (regexp-match #rx"^#lang ([-a-zA-Z/._+]+)" bstr)])
(if m
(link-mod
#:orig? #t
(datum->syntax
#f
(string->symbol (bytes->string/utf-8 (cadr m)))
(vector 'in 1 6 7 (bytes-length (cadr m))))
3)
null))]
[tokens
(sort (append ids mods language
(filter (λ (x) (not (eq? (car x) 'symbol)))
;; Drop #lang entry:
(cdr tokens)))
(λ (a b) (or (< (cadr a) (cadr b))
(and (= (cadr a) (cadr b))
(> (cadddr a) (cadddr b))))))])
(let loop ([pos 0] [tokens tokens])
(cond
[(null? tokens) (list (substring* bstr pos))]
[(eq? (caar tokens) 'white-space) (loop pos (cdr tokens))]
[(= pos (cadar tokens))
(cons (let ([style (caar tokens)]
[s (substring* bstr (cadar tokens) (caddar tokens))])
(if (pair? style)
(a href: (cdr style) class: @list{code@(car style)} s)
(span class: @list{code@style} s)))
(loop (caddar tokens) (cdr tokens)))]
[(> pos (cadar tokens)) (loop pos (cdr tokens))]
[else (cons (substring* bstr pos (cadar tokens))
(loop (cadar tokens) tokens))]))))