racket/collects/meta/web/www/code.rkt
2012-12-27 11:10:40 -06:00

119 lines
5.0 KiB
Racket

#lang meta/web
(require syntax-color/module-lexer setup/xref
scribble/xref scribble/tag)
(provide code)
(define doc-root "http://docs.racket-lang.org/")
(define expand-namespace (make-base-namespace))
(define xref (load-collections-xref))
(define (code . strs)
(define str
(let* ([str (string-append* strs)]
[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])))
(define bstr (string->bytes/utf-8 (regexp-replace* #rx"(?m:^$)" str "\xA0")))
(define in (open-input-bytes bstr))
(define (substring* bstr start [end (bytes-length bstr)])
(bytes->string/utf-8 (subbytes bstr start end)))
(define e
(parameterize ([read-accept-reader #t] [current-namespace expand-namespace])
(expand (read-syntax 'prog (open-input-bytes bstr)))))
(define ids
(let loop ([e e])
(cond
[(and (identifier? e) (syntax-original? e))
(define pos (sub1 (syntax-position e)))
(define b (identifier-binding e))
(define imp?
(and (list? b)
(let-values ([(name base) (module-path-index-split (car b))])
(or name base))))
(define tag (and imp? (xref-binding->definition-tag xref e 0)))
(list (list (cond [(not imp?) 'id]
[(not tag) 'importid]
[else (define-values [p a]
(xref-tag->path+anchor
xref tag #:external-root-url doc-root))
(cons (if (eq? (car tag) 'form)
'linkimportform 'linkimportid)
(if a (format "~a#~a" p a) p))])
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])))
(define (link-mod mp-stx priority #:orig? [always-orig? #f])
(if (or always-orig? (syntax-original? mp-stx))
(let ([mp (syntax->datum mp-stx)])
(define-values [p a]
(xref-tag->path+anchor xref
(make-module-language-tag 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))
(define mods
(let loop ([e e])
(syntax-case e (module #%require begin)
[(module name lang (mod-beg form ...))
(append* (link-mod #'lang 2) (map loop (syntax->list #'(form ...))))]
[(#%require spec ...)
(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])))
(define 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)))
(define raw-tokens
(let loop ([mode #f])
(define-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*)))))
(define tokens
(sort (append ids mods language
(filter (λ (x) (not (eq? (car x) 'symbol)))
;; Drop #lang entry:
(cdr raw-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))
(define style (caar tokens))
(define s (substring* bstr (cadar tokens) (caddar tokens)))
(cons (if (pair? style)
(a href: (cdr style) class: @list{code@(car style)}
rel: 'nofollow 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))])))