day 21 part 1, fun

day21-scratch.lisp

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+;; // https://adventofcode.com/2022/day/21
+;; well, this seems like this could be done with (eval)
+;; would it be possible for me to also translate
+;; xxx + yyy into (call xxx) + (call yyy)
+;; that would be neat
+
+(in-package :day-21)
+
+;; so. have mashmap from symbol name into operation
+;; and have (my-eval)?
+;; it will take symbol name, and either return number directly from the map
+;; or will wrap the names into my-eval and run operation on them?
+
+;; is there a way to have less code and reuse existing lisp things?
+;; if there's direct number, i could just run (defparameter lfqf 4)
+;; and then execute root directly, i think
+;; or what, i'd need to also define all the intermediate symbols,
+;; (setq a (+ c d)) ; complains that C is unbound
+;; how could this be a lazy eval?
+;; well. hm
+;; i could define all of these as macroses?
+(defmacro *test-monkey-hmdt* () 32)
+(+ 3 (*test-monkey-hmdt*))
+
+;; yup, i guess
+
+(defparameter *test-monkey-sllz* 4)
+(eval *test-monkey-sllz*)
+(defparameter *test-monkey-ljgn* 2)
+(defparameter *my-operation* '(+ *test-monkey-sllz* *test-monkey-ljgn*))
+*my-operation*
+(eval *my-operation*)                   ; well, that works ok
+;; so, read all of these things as parameters.
+
+;; "root: pppw + sjmn "
+
+(mapcar #'intern (ppcre:split " " "root: pppw + sjmn "))
+(mapcar #'parse-integer-or-symbol (ppcre:split " " "root: 44"))
+
+(ppcre:regex-replace ":" "root: pppw + sjmn " "")
+
+(line-to-quoted-operation "root: pppw + sjmn")
+(eval (line-to-quoted-operation "dbpl: 5"))
+
+;; well, i'd want to put quoted expression into parameter?
+;; and now i can remove quoting of the defparameter?
+;; and actually define all of the parameters?
+
+(loop
+  for line in (uiop:read-file-lines "day21-test.txt")
+  for definition = (line-to-quoted-operation line)
+  do (eval definition))
+
+(eval root)
+
+(load-file-defs "day21-test.txt")
+(eval root)

day21-test.txt

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+root: pppw + sjmn
+dbpl: 5
+cczh: sllz + lgvd
+zczc: 2
+ptdq: humn - dvpt
+dvpt: 3
+lfqf: 4
+humn: 5
+ljgn: 2
+sjmn: drzm * dbpl
+sllz: 4
+pppw: cczh / lfqf
+lgvd: ljgn * ptdq
+drzm: hmdt - zczc
+hmdt: 32

day21.lisp

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+;; // https://adventofcode.com/2022/day/21
+(defpackage :day-21
+  (:use :cl))
+(in-package :day-21)
+
+(ql:quickload 'cl-ppcre)
+
+(defun parse-integer-or-symbol (str)
+  (let ((maybe-int (parse-integer str :junk-allowed t)))
+    (if maybe-int
+        maybe-int
+        (intern (string-upcase str)))))
+
+
+(defun line-to-quoted-operation (line)
+  (let* ((words (ppcre:split " " (ppcre:regex-replace ":" line "")))
+         (symbols (mapcar #'parse-integer-or-symbol words)))
+    (cond
+      ((= 4 (length symbols))
+       ;; with operation
+       (destructuring-bind (name operand1 op operand2)
+           symbols
+         `(defparameter ,name '(,op (eval ,operand1) (eval ,operand2)))))
+
+      ((= 2 (length symbols))
+       ;; just number
+       (destructuring-bind (name value)
+           symbols
+         `(defparameter ,name ,value))))))
+
+(defun load-file-defs (filename)
+  (loop
+  for line in (uiop:read-file-lines filename)
+  for definition = (line-to-quoted-operation line)
+  do (eval definition)))