When did you first try Lisp seriously, and which Lisp family member was it?
In 1965 or 1966 I encountered Lisp 1.5 and became quite taken with it. However, I couldn't actually run a Lisp program until I got to MIT and got access to a PDP-n running some long-forgotten Lisp dialect. (I don't think it even had a compiler.)
What led you to try Lisp?
I was interested in AI. I started with IPL-V, Newell and Simon's language. It looked like assembly language. Lisp seemed very odd by comparison, but I soon realized just how elegant it was.
Where did your road originate?
In the 1950s list processing seemed like a radical innovation in an array-oriented world. IPL-V's basic datatype was the list, but in a basically different form from Lisp. E.g., every list had a header cell that pointed to the list's property list. Hence there was no unique empty list; you could have as many empty lists as you wanted. There was also no problem adding an element to a list. No need to write (setf (cadr l) (cons x(cadr l))); you just found the second element of l and added element 'x' to it. If the list was empty, it became non-empty. As I said, IPL-V looked like assembly language, but the instructions were in a list. How meta is that? Anyway, I think it's fair to claim that Lisp's property lists descended from those of IPL-V. That would explain, for instance, why property lists aren't in a-list format, which is otherwise very puzzling.
How far have you gotten in your study of Lisp?
I have learned everything there is to know, and have now commenced forgetting things.
What do you think of Lisp so far? I'm still withholding judgment :). Alternative answer: Lisp isn't perfect, but you can fix almost all the problems! Wow!
Switch Date 1960s