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sugar/sugar/file.rkt

100 lines
3.8 KiB
Racket

#lang racket/base
(require racket/list
racket/match
(except-in racket/path filename-extension)
"define.rkt"
"coerce/base.rkt")
;; this is identical to `filename-extension` in `racket/path`
;; but will not treat hidden files as an extension (which is a bug)
(define (filename-extension name)
(match (file-name-from-path name)
[(? path-for-some-system? filename)
(=> resume)
(match (regexp-match #rx#".[.]([^.]+)$" (path->bytes filename))
[(list _ second) second]
[_ (resume)])]
[_ #false]))
(module+ test
(require rackunit)
(require (prefix-in rp: racket/path))
(check-equal? (rp:filename-extension (string->path ".foo")) #"foo") ; bad behavior
(check-false (filename-extension (string->path ".foo")))) ; good behavior
;; does path have a certain extension, case-insensitively
(define+provide+safe (has-ext? x ext)
(pathish? stringish? . -> . boolean?)
(unless (pathish? x)
(raise-argument-error 'has-ext? "pathish?" x))
(unless (stringish? ext)
(raise-argument-error 'has-ext? "stringish?" ext))
(define ext-of-path (filename-extension (->path x)))
(and ext-of-path (string=? (string-downcase (bytes->string/utf-8 ext-of-path))
(string-downcase (->string ext)))))
;; get file extension as a string, or return #f
;; (consistent with filename-extension behavior)
(define+provide+safe (get-ext x)
(pathish? . -> . (or/c #f string?))
(unless (pathish? x)
(raise-argument-error 'get-ext "pathish?" x))
(cond
[(filename-extension (->path x)) => bytes->string/utf-8]
[else #false]))
;; todo: add extensions
(provide+safe binary-extensions)
(define binary-extensions
(map symbol->string '(gif jpg jpeg mp3 png zip pdf ico tar ai eps exe)))
(define+provide+safe (has-binary-ext? x)
(pathish? . -> . boolean?)
(unless (pathish? x)
(raise-argument-error 'has-binary-ext? "pathish?" x))
(for/or ([ext (in-list binary-extensions)]
#:when (has-ext? (->path x) ext))
#true))
;; put extension on path
;; use local contract here because this function is used within module
(define+provide+safe (add-ext x ext)
(stringish? stringish? . -> . pathish?)
(unless (stringish? x)
(raise-argument-error 'add-ext "stringish?" x))
(unless (stringish? ext)
(raise-argument-error 'add-ext "stringish?" ext))
(->path (string-append (->string x) "." (->string ext))))
(define (starts-with? str starter)
(define pat (regexp (format "^~a" (regexp-quote starter))))
(and (regexp-match pat str) #true))
(define (path-hidden? path)
((->string (file-name-from-path path)) . starts-with? . "."))
(define (change-hide-state new-hide-state path)
(define reversed-path-elements (reverse (explode-path path)))
(apply build-path (append (reverse (cdr reversed-path-elements))
(list (if (eq? new-hide-state 'hide)
(format ".~a" (->string (car reversed-path-elements)))
(regexp-replace #rx"^." (->string (car reversed-path-elements)) ""))))))
;; take one extension off path
(define+provide+safe (remove-ext x)
(pathish? . -> . path?)
;; `path-replace-suffix` incorrectly thinks any leading dot counts as a file extension
;; when it might be a hidden path.
;; so handle hidden paths specially.
;; this is fixed in later Racket versions with `path-replace-extension`
(match (->path x)
[(? path-hidden? path) (change-hide-state 'hide (path-replace-suffix (change-hide-state 'unhide path) ""))]
[path (path-replace-suffix path "")]))
;; take all extensions off path
(define+provide+safe (remove-ext* x)
(pathish? . -> . path?)
(let loop ([path (->path x)])
(match (remove-ext path)
[(== path) path]
[path-reduced (loop path-reduced)])))