diff options
| -rw-r--r-- | examples.lisp | 31 | ||||
| -rw-r--r-- | gtwiwtg.lisp | 20 |
2 files changed, 50 insertions, 1 deletions
diff --git a/examples.lisp b/examples.lisp index 221c78e..df50a23 100644 --- a/examples.lisp +++ b/examples.lisp @@ -118,4 +118,33 @@ vector VEC, one at a time." (zip! (range) (file-lines file)))) -;; find all export expressions in my bashrc file + +;;; Silly Scrambler ;;; + + +(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)) + (loop :while (< i len) :do (incf i) (princ pad-char out))))) + +(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 chunk (n str) + (assert (zerop (mod (length str) n))) + (let ((size (/ (length str) n))) + (loop + :for i :below (length str) :by size + :collect (subseq str i (+ i size)) ))) + +(defun descramble (n str) + (concatenate 'string + (collect + (apply #'intersperse! + (mapcar #'seq (chunk n str)))))) diff --git a/gtwiwtg.lisp b/gtwiwtg.lisp index 3cf1871..5e954ee 100644 --- a/gtwiwtg.lisp +++ b/gtwiwtg.lisp @@ -629,6 +629,26 @@ Caveat: (list (filter! pred gen1) (filter! (complement pred) gen2)))) +(defun intersperse! (gen1 gen2 &rest gens) + (inflate! #'seq (apply #'zip! gen1 gen2 gens))) + +(defun truncate! (n gen) + (map! #'first (zip! gen (times n)))) + +(defun inject! (fn gen) + (map! (lambda (x) (funcall fn x) x) gen)) + +(defun disperse! (n gen) + (loop + :for i :below n + :for cloned :in (nfurcate! n gen) + :collect + (let ((j i)) + (map! #'second + (filter! (lambda (pair) (= j (mod (first pair) n))) + (indexed! cloned)))))) + + ;;; CONSUMERS (defmacro for (var-exp gen &body body) |