On Tue, Feb 11, 2025 at 10:16:14PM -0800, Lindsay Lawrence wrote: > Is there a way to distinguish a list from a cons pair? > > The 'pair' function does not seem to do what I want.
It depends on how you define a list. I would say it is a cell with a non-NIL and non-atomic CDR, then (1 . 2) is not a list but (1 . NIL) # (1) or (1 . (2 . NIL)) # (1 2) is. I would also call (1 . (2 . 3)) # (1 2 . 3) a list. BTW, 'fin' can be used to distinguish them: : (fin (1 2)) -> NIL : (fin (1 2 . 3)) -> 3 > I would like to be able to distinguish the cons pair structure from 'list' So perhaps : (lst? (cdr Pair)) ☺/ A!ex -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
