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advent-of-code/2022/lib.lisp
Aryadev Chavali 65b65a2a3e Introduce tests for split-by-first and split-by-completely
Allows one to split by string delimiter, or anything else.
2024-10-30 22:33:31 +00:00

49 lines
1.3 KiB
Common Lisp

(defun string-to-clist (str)
(coerce str 'list))
(defun clist-to-string (clist)
(if (atom clist)
(string clist)
(coerce clist 'string)))
(defun split-by-first (lst delim &optional (test #'eq))
"Splits LST by the first instance of DELIM"
(let ((pos (position delim lst :test test)))
(if pos
(list (subseq lst 0 pos) (subseq lst (+ pos 1)))
(error (format nil "No instance of ~a was found in ~a" delim lst)))))
(defun split-by-completely (lst delim &optional (test #'eq))
(cond
((or (null lst) (not (cdr lst)))
(list (car lst)))
((not (member delim lst :test test))
(list lst))
(t
(loop
for (start rest) = (split-by-first lst delim test)
then (split-by-first rest delim test)
collect start
if (not (member delim rest :test test))
collect rest
and do (loop-finish)))))
(defun get-lines (input-string)
(with-input-from-string (s input-string)
(loop for line = (read-line s nil)
while line
collect line)))
(defun remove-nth (n lst)
(loop for el in lst
for i from 0
if (not (= i n))
collect el))
(defmacro --> (first &rest functions)
(let ((builder first))
(loop for function in functions
do (setq builder `(let ((it ,builder))
,function)))
builder))