[pjmlp]

Actually, no.

"AN ALGORITHMIC THEORY OF LANGUAGE", 1962

https://apps.dtic.mil/sti/tr/pdf/AD0296998.pdf

In this paper they are known as plexes, eventually ML and CLU will show similar approaches as well.

Only much latter would Lisps evolve from plain lists and cons cells.

[ryao]

You caused me to do some digging. That publication is dated November 1962. The Lisp 1.5 manual’s preface is dated August 17, 1962, which is even older. It describes lambdas and property lists, which seem like they can be used to implement ADTs, although I do not have a Lisp 1.5 interpreter since those are obsolete, so I cannot verify that. Computer history articles claim that Simula, the first object oriented language, was born in May 1962, but was not actually operational until January 1965:

https://history-computer.com/software/simula-guide/

Thus, while I had thought Lisp had ADT concepts before the first OOL existed, now I am not sure. My remark that they originated in Lisp had been said with the intention that I was talking about the first language to have it. The idea that the concept had been described outside of an actual language is tangential to what I had intended to say, which is news to me. Thanks for the link.

[hiker]

Plexes are first mentioned in 1960

https://dl.acm.org/doi/pdf/10.1145/366199.366256

and the paper even starts with a critique of the efficiency of Lisp's approach for representing data with cons pairs (citing McCarthy's paper from the same year).

You might also want to watch Casey's great talk on the history of OOP

https://www.youtube.com/watch?v=wo84LFzx5nI