slurp.lisp

   1 (defpackage "SLURP"
   2   (:use "CL")
   3   (:export "SLURP"
   4            "STREAM-LENGTH"))
   5
   6 (in-package "SLURP")
   7
   8 (defun stream-length (stream)
   9   "Returns the length of STREAM, or NIL if the length can't be determined."
  10   (check-type stream stream)
  11   (handler-case (file-length stream)
  12     (type-error () nil)))
  13
  14 (defgeneric slurp (arg &key element-type))
  15
  16 (defmethod slurp ((string string) &key (element-type 'character))
  17   (slurp (parse-namestring string) :element-type element-type))
  18
  19 (defmethod slurp ((pathname pathname) &key (element-type 'character))
  20   (with-open-file (stream pathname :direction :input :element-type element-type)
  21     (slurp stream)))
  22
  23 (defmethod slurp ((stream stream) &key element-type)
  24   (declare (ignore element-type))
  25   (let ((stream-element-type (stream-element-type stream)))
  26     (cond ((subtypep stream-element-type 'character)
  27            (coerce (loop for c = (read-char stream nil nil)
  28                          while c
  29                          collect c) 'string))
  30
  31           ((subtypep stream-element-type 'unsigned-byte)
  32            (let ((stream-length (stream-length stream)))
  33              (if stream-length
  34                  (let* ((seq (make-array stream-length :element-type stream-element-type))
  35                         (seq-length (read-sequence seq stream)))
  36                    (if (= seq-length stream-length)
  37                        seq
  38                        (subseq seq 0 seq-length)))
  39                  (let ((byte-list (loop for b = (read-byte stream nil nil)
  40                                         while b
  41                                         collect b)))
  42                    (make-array (length byte-list) :element-type stream-element-type :initial-contents byte-list)))))
  43
  44           (t (error "Unexpected stream element type ~S." stream-element-type)))))