cantedraw.lisp -> main.lisp

1 files changed, 49 insertions, 0 deletions

diff --git a/main.lisp b/main.lisp
new file mode 100644
index 0000000..32a0088
--- /dev/null
+++ b/main.lisp
@@ -0,0 +1,49 @@
+;;; main.lisp - 2025-02-11
+
+;; Copyright (C) 2025 Aryadev Chavali
+
+;; This program is distributed in the hope that it will be useful, but WITHOUT
+;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+;; FOR A PARTICULAR PURPOSE.  See the GNU General Public License Version 2 for
+;; details.
+
+;; You may distribute and modify this code under the terms of the GNU General
+;; Public License Version 2, which you should have received a copy of along with
+;; this program.  If not, please go to <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; Implementation of `main' package.  Defines the entrypoint of the program,
+;; handling any input from the user and passing it into the system.
+
+;;; Code:
+
+(in-package :main)
+
+(fn read-input (&optional (prompt "> ")) (-> (&optional string) string)
+  (format t "~a" prompt)
+  (force-output)
+  (read-line))
+
+(fn parse-integers (input) (-> (string) list)
+  (->> input
+       uiop:split-string
+       (mapcar #'parse-integer*)
+       (remove-if #'null)))
+
+(fn read-integers () (-> nil list)
+  (->> (read-input "Enter numbers: ")
+       parse-integers))
+
+(fn read-until-integers () (-> nil list)
+  (let ((inp (read-integers)))
+    (while (null inp)
+      (format t "Need at least one integer...~%")
+      (force-output)
+      (setq inp (read-integers)))
+    inp))
+
+(defun start ()
+  (--> (read-until-integers)
+       (cons '+ _)
+       (format t "~a = ~a~%" _ (eval _))))