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Comment by chc | Hacker News Reader

If you've taken the time to learn Lisp and it hasn't impressed you even a little bit, you're made of more stubborn stuff than most programmers.

But most of the "non-academic" languages wind up cribbing from the academic languages anyway. For example, Python is very much a Working Man's language, but it pervasively uses not only garbage collection (from Lisp), but also list comprehensions borrowed directly from Haskell!

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I'm impressed with lambda calculus as a mathematical formalisms and its equivalence with TMs, and I am impressed but not overly enamored with homoiconicity & metaprogramming/macros. I like conditionals. Not a fan of marketing minimal syntax but having special forms. Not a fan of cons as a a building block for everything. Not a big believer in garbage collection. And certainly not a believer that Lisp is a practical programming language for much of anything these days.

But don't let me stop you from caaaaadring away!

> Not a big believer in garbage collection.

This makes me seriously wonder whether you're trolling. Out of purest and most innocent curiosity, what sort of programming do you do?

I am mostly doing programming in languages with GC, which in this case is fine because it's OK for it to go, you know, kind of slow.

Often, manual allocation is even slower.

http://lambda-the-ultimate.org/node/2552

No no, he's an expert programmer that can do repetitive tasks better than a computer.

With only three times as much memory, it runs on average 17% slower than explicit memory management. However, with only twice as much memory, garbage collection degrades performance by nearly 70%. When physical memory is scarce, paging causes garbage collection to run an order of magnitude slower than explicit memory management.

I don't see how this article is helping your point; that's a pretty massive hit. Even worse, this is a GC-style program modified to use explicit malloc/free. Programming with manual memory management encourages a very different style of programming where you try to use malloc/free as little as possible, and you try keep memory for various things in contiguous chunks of memory.

EDIT:

This comment is interesting: http://lambda-the-ultimate.org/node/2552#comment-38915

I think it's the discussion that we're meant to read, not just the OP. Most of the comments are pointing out questionable assumptions in the study (e.g. even though they admit that actually changing the program to use manual memory management would be nearly intractable, they assume that essentially running an AOT garbage collector is equivalent).

They may have had Appel's "Garbage Collection Can Be Faster Than Stack Allocation" (http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.39.8...) in mind.

Also, the technique described in that comment (forking processes with finite lifetimes, allocating but not freeing, terminating and letting the OS clean up all at once) is also what Erlang does, and it seems to work pretty well in practice. Each process has its own arena, for allocation purposes.

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