string.lisp

(cl:in-package #:incf-cl)

;;; Copyright (c) 2007-2019 Juan M. Bello Rivas <jmbr@superadditive.com>
;;;
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;;; obtaining a copy of this software and associated documentation
;;; files (the "Software"), to deal in the Software without
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;;; of the Software, and to permit persons to whom the Software is
;;; furnished to do so, subject to the following conditions:
;;;
;;; The above copyright notice and this permission notice shall be
;;; included in all copies or substantial portions of the Software.
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(defun string-join (list &optional (sep " "))
  "Returns a string joining each string in LIST by SEP.  If SEP is not
specified, the default separator is a space."
  ;; TODO This should use intersperse as soon as it works with
  ;; arbitrary sequences.

  ;; Based on Pascal Costanza's approach at
  ;; http://groups.google.com/group/comp.lang.lisp/msg/8adbef3a067ece78
  (when list
    (with-output-to-string (stream)
      (write-string (first list) stream)
      (dolist (string (rest list) stream)
        (write-string sep stream)
        (write-string string stream)))))