Comment by chimeracoder | Hacker News Reader

Comment by chimeracoder | Hacker News Reader

Parent Full thread

> Macros? There are numerous arguments on both sides about whether those are good or bad.

Every argument I've ever heard about macros falls into one of two categories:

1. Concerns about overuse, which says nothing about correctly used macros - any tool can be overused or used incorrectly.

2. Complaints about macro systems from heteroiconic languages like C++ - these two concepts are similar in name only. Lisp macros have nothing to do with macros in any other language, and they provide freedom that is literally unavailable in any other[1], as explained well in this description: http://lists.warhead.org.uk/pipermail/iwe/2005-July/000130.h...

[1] Yes, yes, Turing-completeness, so nothing is stopping you from writing your own parser from scratch. But the whole point is that Lisp doesn't require you to go through all of that - and secondarily, even if you did, parsing sexprs is so easy, you've finished before you've even started.

1. True. My concern after years of development both in and out of corporate environments is that any tool available will be misused if given the chance. The goal is to minimize the damage as much as possible. If I could be surrounded by the cream of the crop at all times, that'd be great, but I'm not and most developers aren't.

2. I'm aware of this as well. I developed in Lisp for two years. Lisp macros are not comparable to C macros. I also didn't say they were all bad, just that there are arguments to be had about their utility. For example, OOP in Lisp has been described many times as a "leaky abstraction". In my opinion, it just plain sucks. It gets the job done, but I always feel dirty afterwards. It shows the power of macros and Lisp, but it also shows the limitations of not changing your language to support a little syntactic sugar.

BTW, I know it's not apparent from my post, but I actually like Lisp, I just don't think it is the answer to any question that is being posed right now.

"they provide freedom that is literally unavailable in any other"

There have been lots of arguments on LtU about this. You can go very, very far with either laziness or lightweight closures. Laziness didn't go all the way with Haskell, whence Template Haskell; I don't know enough about Smalltalk to know if they've managed to get by with extremely (syntactically) lightweight closures.

Thank you for that link. This is the first explanation of macros I've seen that actually shows some use cases.

Reply on news.ycombinator.com