[pjmlp]

To which I gave the example of 80's Thinking Machines as "older hardware".

I could also given Symbolics as example.

As 40 year old examples, in 20 years the use of Lisp improved a lot since the early IBM mainframes.

[taeric]

But what is that contradicting? Lisp certainly ran on older hardware.

My assertion is that "functional" is not the defining feature of lisp. My evidence is much of modern functional programming was not done for a large part of it's history. My claim is further that many modern idioms couldn't be done on older hardware. Not that lisp couldn't run there, but that modern practices couldn't. Regardless of language.

Functional is certainly a feature. Even a prominent one. Just not a defining one.

[pjmlp]

One of the ideas behind Thinking Machines with StarLisp was functional programming.

[taeric]

Doesn't that still support what I'm saying? Specifically, was it a defining idea, or the defining idea?

I've never claimed that functional was not a facet of lisp. Just that it is not the facet.

Now, the claim I'm making that requires the most evidence is that many of the common functional datastructures people learn of today would not have been feasible on older hardware. I will not claim that they are too slow. I will claim that they are a bit too memory intensive for older hardware.

So, immutable lists are not equal to cons lists. Since most implementations allow direct modifications of cons lists. (Scheme bucked this trend, and people laud it for that. But it was certainly not the norm early on.)

Similarly, the highly branched vectors and other datastructures popular in clojure and friends are just too unfriendly to hardware. Could they have been done? Possibly, but the mutable structures had massive advantages on the hardware of the time. (Arguably, they still have advantages, just nowadays we get to make more tradeoffs between bleeding performance and maintenance.)

I'm definitely open to the idea what I'm saying is flat out wrong. I doubt I've reached my quota on stupid claims for my lifetime. And if my reading of your post was as off as one of the siblings where you weren't trying to contradict my claim, but strengthen it, my apologies. :) And my thanks for sticking with the thread.