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andlys/fun.lisp

Created September 12, 2017 06:08
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fun.lisp
(defmacro nth-expr (n &rest args)
(let ((g (gensym)))
`(let ((,g (1- ,n)))
(eval (nth ,g ',args))))) ; TODO: make this work without eval function
(defun watch () (print 'evaluated!))
(let ((n 2))
(macroexpand-1 '(nth-expr n (watch) (+ 1 3) 'value)))
(let ((n 2))
(nth-expr n (watch) (+ 1 3) 'value))
; => 4
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