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))
  15
  16 (defmethod slurp ((string string))
  17   (slurp (parse-namestring string)))
  18
  19 (defmethod slurp ((pathname pathname))
  20   (with-open-file (stream pathname :direction :input)
  21     (slurp stream)))
  22
  23 (defmethod slurp ((stream stream))
  24   (let ((stream-element-type (stream-element-type stream)))
  25     (cond ((subtypep stream-element-type 'character)
  26            (coerce (loop for c = (read-char stream nil nil)
  27                          while c
  28                          collect c) 'string))
  29
  30           ((subtypep stream-element-type 'unsigned-byte)
  31            (let ((stream-length (stream-length stream)))
  32              (if stream-length
  33                  (let ((seq (make-array stream-length :element-type stream-element-type)))
  34                    (if (= (read-sequence seq stream) stream-length)
  35                        seq
  36                        (error "short read")))
  37                  (let ((byte-list (loop for b = (read-byte stream nil nil)
  38                                         while b
  39                                         collect b)))
  40                    (make-array (length byte-list) :element-type stream-element-type :initial-contents byte-list)))))
  41
  42           (t (error "Unexpected stream element type ~S." stream-element-type)))))