Comment by incepted | Hacker News Reader

Comment by incepted | Hacker News Reader

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> Lisp is one of the few languages that can say it actually doesn't age; Common Lisp code that was written 20+ years ago is often used today without a single change. You can't say that about most of the popular languages.

Examples?

This is certainly false for most languages in use today: C, C++, Java, even C#: code written in these languages 15-20-30 years ago can still be compiled and run fine today.

I'm not sure what this proves much, though.

> I see a lot of talk about how macros can be unreadable and all, but frankly, IMO that's totally backwards.

Why?

Macros are basically syntax defined for a specific task. Why is it so hard to see that this can lead to an explosion of unreadable code if left unchecked? Wouldn't you be concerned if you had to work on a huge code base where most of the code is written using macros?

I would run away, personally.

> it was in Lisp age people actually cared about buildings systems that would live for decades.

We still care about this today. Even more than in "Lisp age" because we know how long code will be around. Which is one of the reasons why we have been moving at an accelerated pace toward statically typed languages.

> Examples?

Half of the libraries in the Lisp ecosystem? They were done once, polished over years, and pretty much did not age with time.

> Why is it so hard to see that this can lead to an explosion of unreadable code if left unchecked? Wouldn't you be concerned if you had to work on a huge code base where most of the code is written using macros?

Because again, readable code is not about using the same small subset of programming language constructs and design patterns everyone knows. It's about clear communication. Macros done right let you express your ideas more clearly, and hide/remove unnecessary boilerplate that makes code hard to read. Think about e.g. Java or C++ codebases, where 50%+ code is scaffolding and otherwise irrelevant to what the program is meant to do / communicate. Lisp macros let you hide all that.

Now if you do macros wrong, then of course code will be unreadable. But the same is when you design your API wrong using functions, or using classes.

Moreover, whining about macros being hard reminds me of whining about ternary operator in C++/Java/PHP world, where many people say not to use them because "juniors don't understand it". The solution isn't to ban ternary operators - it's for the juniors and the whiners to get their shit together and spend 5 minutes learning about it.

> Even more than in "Lisp age" because we know how long code will be around. Which is one of the reasons why we have been moving at an accelerated pace toward statically typed languages.

Do we? All I see is throwaway code. Especially on the Web, everything is ephemeral, and nobody honestly expects stuff to last more than few years (most startups are actually based on this assumption).

> Why is it so hard to see that this can lead to an explosion of unreadable code if left unchecked?

Anything can lead to an explosion of unreadable code if left unchecked. Any language feature, with no exceptions. Variables, loops, functions, types - you name it. Anything can go wrong if used with a bit of imagination.

Macros, on the other hand, provide an exclusive way of eliminating this complexity. A way of eliminating degrees of freedom of what can go wrong. Nothing else is capable of doing it.

> Wouldn't you be concerned if you had to work on a huge code base where most of the code is written using macros?

I'd be extremely happy to be able to work on such a well designed project.

> I would run away, personally.

It only means that you don't know how to use macros. Nothing else.

> I'd be extremely happy to be able to work on such a well designed project.

You really think the project is well designed just because they use macros, without even looking at the code or knowing the engineers?

Now I really think you're not for real and just messing with us.

I think that it can at least be a sign of a good design. If it went that far and still kicking, chances are pretty high.

Any comments on any other points I made?

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