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Comment by medo-bear | Hacker News Reader

> For example: hot upgrading. The fact that an Erlang process can tail call itself means that you can swap in a new process with the same signature at the tail call of the old process. Nobody else does this that I know of

common lisp is in a league of its own when it comes to hot reloading and debugging

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Question is if Common Lisp got the idea from Erlang, or vice-versa. Common Lisp first appeared in 1984 while Erlang appeared in 1986. If so, the original point of "None of the other programming languages seem to have learned much of anything from Erlang" might remain accurate.

In the 70s Ericsson programmed their telephone switches in a proprietary language called PLEX. It had hot code swapping, so when Joe Armstrong started working on Erlang to replace PLEX in the 80s this was a requirement. Dropping a few thousands of calls just to do an update simply wasn't an option.

On the other hand, even the first versions of lisps (as far as I can gather at least) had `eval`, meaning a running program could accept external output and update itself. And this was in the 60s.

The question remains :)

Lisp would also be able to compile code to assembler, run an assembler and load the generated code into the runtime.

I would think (without knowing too much about Erlang's mechanisms) that the mechanisms of Erlang are quite different from what a Lisp runtime typically does. The Lisp runtime is just one process. Erlang is concerned with multiple processes, which are strongly isolated.

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