diff options
| -rw-r--r-- | users/wpcarro/emacs/pkgs/list/list.el | 18 | ||||
| -rw-r--r-- | users/wpcarro/emacs/pkgs/list/tests.el | 10 |
2 files changed, 28 insertions, 0 deletions
diff --git a/users/wpcarro/emacs/pkgs/list/list.el b/users/wpcarro/emacs/pkgs/list/list.el index 03382991e0..a1822e77ff 100644 --- a/users/wpcarro/emacs/pkgs/list/list.el +++ b/users/wpcarro/emacs/pkgs/list/list.el @@ -160,6 +160,24 @@ (list-cons x acc))) xs))) +(defun list-chunk (n xs) + "Chunk XS into lists of size N." + (if (> n (length xs)) + (list xs) + (->> xs + (list-reduce '(:curr () :result ()) + (lambda (x acc) + (let ((curr (plist-get acc :curr)) + (result (plist-get acc :result))) + (if (= (- n 1) (length curr)) + `(:curr () :result ,(list-cons (list-reverse (list-cons x curr)) result)) + `(:curr ,(list-cons x curr) :result ,result))))) + (funcall (lambda (xs) + (let ((curr (plist-get xs :curr)) + (result (plist-get xs :result))) + (if curr (list-cons curr result)) result))) + list-reverse))) + ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; Predicates ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; diff --git a/users/wpcarro/emacs/pkgs/list/tests.el b/users/wpcarro/emacs/pkgs/list/tests.el index abba6b59d6..a6096a1d6e 100644 --- a/users/wpcarro/emacs/pkgs/list/tests.el +++ b/users/wpcarro/emacs/pkgs/list/tests.el @@ -42,3 +42,13 @@ (ert-deftest list-join () (should (equal "foo-bar-baz" (list-join "-" '("foo" "bar" "baz"))))) + +(ert-deftest list-chunk () + (should (equal '((1 2 3 4 5 6)) + (list-chunk 7 '(1 2 3 4 5 6)))) + (should (equal '((1) (2) (3) (4) (5) (6)) + (list-chunk 1 '(1 2 3 4 5 6)))) + (should (equal '((1 2 3) (4 5 6)) + (list-chunk 3 '(1 2 3 4 5 6)))) + (should (equal '((1 2) (3 4) (5 6)) + (list-chunk 2 '(1 2 3 4 5 6))))) |