Aryadev Chavali
279437cb81
Given a list and index into that list, return a cons where the car is all elements up to that index (exclusive) and the cdr is the rest of the list.
39 lines
1.2 KiB
Common Lisp
39 lines
1.2 KiB
Common Lisp
;;; lib.functions.lisp - 2025-02-09
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;; Copyright (C) 2025 Aryadev Chavali
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;; This program is distributed in the hope that it will be useful, but WITHOUT
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;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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;; FOR A PARTICULAR PURPOSE. See the GNU General Public License Version 2 for
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;; details.
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;; You may distribute and modify this code under the terms of the GNU General
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;; Public License Version 2, which you should have received a copy of along with
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;; this program. If not, please go to <https://www.gnu.org/licenses/>.
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;;; Commentary:
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;; Helpful functions for usage throughout the project.
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;;; Code:
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(in-package :lib.functions)
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(fn range (start end &optional (step 1)) (-> (fixnum fixnum &optional fixnum) list)
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"Make a list of numbers from START to END (exclusive). If STEP is given, then
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each member is STEP distance apart."
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(if (<= end start)
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(error (format nil "~a < ~a" end start))
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(loop :for i :from start :to (1- end) :by step
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:collect i)))
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(fn parse-integer* (inp) (-> (string) (or integer list))
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(parse-integer inp :junk-allowed t))
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(fn take (n lst) (-> (fixnum list) list)
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(subseq lst 0 n))
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(fn split (n lst) (-> (fixnum list) list)
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(cons (take n lst)
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(subseq lst n)))
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