(in-package :cl-user)

(defpackage ca.mhcat.advent2022
  (:use :cl))
(in-package :ca.mhcat.advent2022)

(defun load-lines (fname)
  (let ((sysroot (asdf:system-source-directory :ca.mhcat.advent2022))
        (frelpath (merge-pathnames (pathname "data/") (pathname fname))))
    (with-open-file (stream (merge-pathnames frelpath sysroot))
      (loop for line = (read-line stream nil)
            while line collect line))))

(defun compose (&rest fns)
  "Paul Graham, with some refinement from stackoverflow:

https://stackoverflow.com/questions/5928106/compose-example-in-paul-grahams-ansi-common-lisp"
  (lambda (arg)
    (reduce 'funcall fns
            :from-end t
            :initial-value arg)))

(defun juxtapose (&rest fns)
  (lambda (arg)
    (reduce (lambda (lst fn)
              (cons (funcall fn arg) lst))
            (reverse fns)
            :initial-value (list))))