commander-s/scheme/complete.scm

119 lines
3.6 KiB
Scheme

(define-record-type completion-set :completion-set
(really-make-completion-set strings cache)
completion-set?
(strings completion-set-strings set-completion-set-strings!)
(cache completion-set-cache set-completion-set-cache!))
(define (make-empty-completion-set)
(really-make-completion-set '() '()))
(define (make-completion-set strings)
(really-make-completion-set
(lset-intersection strings strings) '()))
(define (make-completion-set-for-executables path-list)
(really-make-completion-set
(executables-in-path-list path-list) '()))
(define (adjoin-completion-set cs string)
(really-make-completion-set
(cons string (completion-set-strings cs)) '()))
(define (completions-for cs prefix)
(let ((maybe-result (check-cache-for-prefix cs prefix)))
(or maybe-result
(let ((result (strings-with-prefix
(completion-set-strings cs) prefix)))
(add-to-cache cs prefix result)
result))))
;; cached prefix version
(define *completion-check-executable* #f)
(define (strings-with-prefix strings prefix)
(let ((plen (string-length prefix)))
(filter (lambda (s)
(and (>= (string-length s) plen)
(string=? (substring s 0 plen) prefix)))
strings)))
(define (check-cache-for-prefix cs prefix)
(let* ((cache-alist (completion-set-cache cs))
(p (assoc prefix cache-alist)))
(cond
(p => cdr)
(else
(let loop ((nprefix prefix))
(if (string=? nprefix "")
#f
(let* ((nprefix (substring prefix 0 (- (string-length nprefix) 1)))
(p (assoc nprefix cache-alist)))
(if p
(strings-with-prefix (cdr p) prefix)
(loop nprefix)))))))))
(define (has-prefix prefix s)
(let ((pl (string-length prefix)))
(and (>= (string-length s) (string-length prefix))
(string=? (substring s 0 pl) prefix))))
(define (add-to-cache cs prefix list)
(let* ((cache-alist (completion-set-cache cs))
(prefixes (strings-with-prefix (map car cache-alist) prefix)))
(receive (longer-ones others)
(partition (lambda (p)
(has-prefix prefix (car p)))
cache-alist)
(set-completion-set-cache!
cs
(cons (cons prefix (append list (append-map cdr longer-ones)))
others)))))
(define (executables-in-path/prefix cs prefix)
(let ((maybe-result (check-cache-for-prefix cs prefix)))
(or maybe-result
(let ((result (append-map! (lambda (dir)
(dir-executables/prefix dir prefix))
(thread-fluid exec-path-list))))
(add-to-cache cs prefix result)
result))))
(define completions-for-executables executables-in-path/prefix)
(define (dir-executables/prefix dir prefix)
(if (file-readable? dir)
(map file-name-nondirectory
(let ((files (glob (string-append dir "/" prefix "*"))))
(if *completion-check-executable*
(filter executable? files)
files)))
'()))
;; caching version
(define *cache* #t)
(define (executables-in-path)
(or *cache*
(begin
(set! *cache* (executables-in-path-list (thread-fluid exec-path-list)))
*cache*)))
(define (executables-in-path-list path-list)
(append-map! dir-executables path-list))
(define (dir-executables dir)
(if (file-readable? dir)
(map file-name-nondirectory
(glob (string-append dir "/*")))
'()))
(define (executable? name) ;; TODO maybe check if executable by this user
(with-errno-handler
((errno packet)
(else #f))
(let ((info (file-info name)))
(and (file-info-executable? info)
(file-info-regular? info)))))