racket/collects/setup/main-collects.ss

83 lines
3.2 KiB
Scheme

(module main-collects mzscheme
(require "dirs.ss")
(provide path->main-collects-relative
main-collects-relative->path)
;; Historical note: this module is based on the old "plthome.ss"
;; The `path->main-collects-relative' and
;; `main-collects-relative->path' functions are used to store paths
;; that are relative to the main "collects" directory, such as in
;; .dep files. This means that if the plt tree is moved, .dep files
;; still work. It is generally fine if
;; `path->main-collects-relative' misses some usages, as long as it
;; works when we prepare a distribution tree. Otherwise, things
;; will continue to work fine and .dep files will just contain
;; absolute path names. These functions work on .dep elements:
;; either a pathname or a pair with a pathname in its cdr; the
;; `path->main-collects-relative' pathname will itself be a pair.
(define (simplify-bytes-path bytes)
(path->bytes (simplify-path (bytes->path bytes))))
(define simplify-path*
(if (eq? 'windows (system-type))
(lambda (str)
(regexp-replace* #rx#"\\\\" (simplify-bytes-path str) #"/"))
simplify-bytes-path))
(define main-collects-dir-bytes
(delay (and (find-collects-dir)
(path->bytes (find-collects-dir)))))
(define main-collects-dir/
(delay (and (force main-collects-dir-bytes)
(regexp-replace #rx#"/?$"
(simplify-path* (force main-collects-dir-bytes))
#"/"))))
(define main-collects-dir/-len
(delay (and (force main-collects-dir/)
(bytes-length (force main-collects-dir/)))))
(define (maybe-cdr-op fname f)
(lambda (x)
(cond [(and (pair? x) (not (eq? 'collects (car x))))
(cons (car x) (f (cdr x)))]
[else (f x)])))
;; path->main-collects-relative* : path-or-bytes -> datum-containing-bytes-or-path
(define (path->main-collects-relative* path)
(let* ([path (cond [(bytes? path) path]
[(path? path) (path->bytes path)]
[else (error 'path->main-collects-relative
"expecting a byte-string, got ~e" path)])]
[path* (simplify-path* path)]
[mcd-len (force main-collects-dir/-len)])
(cond [(and path*
mcd-len
(> (bytes-length path*) mcd-len)
(equal? (subbytes path* 0 mcd-len)
(force main-collects-dir/)))
(cons 'collects (subbytes path* mcd-len))]
[(equal? path* (force main-collects-dir/)) (cons 'collects #"")]
[else path])))
;; main-collects-relative->path* : datum-containing-bytes-or-path -> path
(define (main-collects-relative->path* path)
(cond [(and (pair? path)
(eq? 'collects (car path))
(bytes? (cdr path)))
(let ([dir (or (find-collects-dir)
;; No main "collects"? Use original working directory:
(find-system-path 'orig-dir))])
(if (equal? (cdr path) #"")
dir
(build-path dir (bytes->path (cdr path)))))]
[(bytes? path) (bytes->path path)]
[else path]))
(define path->main-collects-relative (maybe-cdr-op 'path->main-collects-relative path->main-collects-relative*))
(define main-collects-relative->path (maybe-cdr-op 'main-collects-relative->path main-collects-relative->path*))
)