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authorDarren Bane <darren.bane@emdalo.com>2020-08-21 19:40:30 +0100
committerDarren Bane <darren.bane@emdalo.com>2020-08-21 19:40:30 +0100
commite6931993d7193b60881d0303110974b6af6af852 (patch)
treec6ace92a2e93aa13f3b44d32439d93fd29bfaacb /cfree-fall.lisp
parent5c4dfb5d3e84be9f7e4b9ea8383fcb9de70862aa (diff)
downloadlsp-e6931993d7193b60881d0303110974b6af6af852.tar.gz
Some more ISLisp->CL examples
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+;; TODO: air resistance, terminal velocity
+(defconstant +G+ 9.81)
+(defvar *alt* 20000)
+(defvar *v* 0)
+(defun one-step ()
+  (setq *alt* (- *alt* *v*))
+  (setq *v* (+ *v* +G+))
+  (format *standard-output* "~A~%" *alt*))
+(defun my-main ()
+  (loop while (> *alt* 0)
+        do (one-step)))
+
+;;; And here's an example from GNAT:
+(defun free-fall ()
+  (format *standard-output* "Gravitational constant: ~A~%" +G+)
+  (format *standard-output* "Twice that: ~A~%" (* 2 +G+))
+  (let* ((time 10)
+         (distance (* 0.5 +g+ (expt time 2))))
+    (format *standard-output* "Distance travelled in 10 seconds of free fall: ~A~%" distance)))