diff options
| -rw-r--r-- | README.md | 30 | ||||
| -rw-r--r-- | examples.lisp | 2 |
2 files changed, 31 insertions, 1 deletions
@@ -87,6 +87,36 @@ example apears at the end of the document, following the tutorial. ``` +### A Silly Scrambler + +``` lisp + +;; see examples.lisp for defuns of PAD and CHUNK + +> (defun scramble (n str) + (assert (< n (length str))) + (let ((str (pad str (* n (ceiling (/ (length str) n)))))) + (concatenate 'string + (apply #'nconc + (mapcar #'collect + (disperse! n (seq str))))))) + +> (defun descramble (n str) + (concatenate 'string + (collect + (apply #'intersperse! + (mapcar #'seq (chunk n str)))))) + + +> (scramble 3 "this will be scrabled, ya dig?") + +"tsi rbdyd?h lbsal,ai iwlecme g " + +> (descramble 3 *) +"this will be scrambled, ya dig? " + +``` + ## Tutorial GTWIWTG is a tiny library for creating and using generators. diff --git a/examples.lisp b/examples.lisp index df50a23..33ae013 100644 --- a/examples.lisp +++ b/examples.lisp @@ -122,7 +122,7 @@ vector VEC, one at a time." ;;; Silly Scrambler ;;; -(defun pad (str len &optional (pad-char #\Space])) +(defun pad (str len &optional (pad-char #\Space)) (let ((i 0)) (with-output-to-string (out) (loop :for c :across str :do (incf i) (princ c out)) |