[d110af5ccf]

> the language is fairly unusable until you write lots of macros

This is not (typically) the case. It would be like saying that you need to write lots of templates to get things done in D. Metaprogramming is certainly very nice to have but it's not a requirement for the vast majority of tasks.

It's important to note that Lisps are an entire family of languages; some implementations are batteries included while others are extremely minimal. Where things can get a bit confusing is that many macro implementations are so seamless that significant pieces of core language functionality are built in them. Schemes tend to take this to an extreme, with many constructs that I would consider essential to productive use of the language provided as SRFIs.

> macros then become your personal undocumented wacky language

That's Doing It Wrong™. You could as well argue to remove goto from a language because sometimes people abuse it and write spaghetti. C++ has operator overloading. D has alias this. If (for example) a DSL is the appropriate tool then being able to use macros to integrate it seamlessly into the host language is a good thing.

[WalterBright]

> it's not a requirement for the vast majority of tasks.

Right, but the temptation to do it is irresistible.

> That's Doing It Wrong™

Of course it's doing it wrong. The point is, that seems to always happen because the temptation is irresistible.

> goto

I rarely see a goto anymore. It just doesn't have the temptation that macros do.

> alias this

Has turned out to be a mistake.

> integrate it seamlessly into the host language is a good thing

Supporting the creation of embedded DSLs is a good thing. Hijacking the syntax of the language to create your own language is a bad thing. I've seen it over and over, it never works out very well. It's one of those things you just have to experience to realize it.

D's support for DSLs comes from its ability to manipulate string literals at compile time, generate new strings, and mixin those strings into the code. This is clearly distinguishable in the source code from ASTs.

[d110af5ccf]

Fair enough, it seems we have very different philosophies on this particular issue. Without oft maligned features such as alias this and operator overloading I never would have given D a try as an alternative to C++.

I'd like to suggest that I think you might be missing some perspective here. You say that misuse of macros always happens and that you've seen it over and over. Yet if you explore the Scheme ecosystem you might notice that significant parts of any given implementation often take the form of macros. Racket in particular fully embraces the idea of the programmer mixing customized languages together and while examples of bad code certainly exist it seems to work out quite well on the whole.

To be clear, I do appreciate having easy access to tools that are simple and safe. I just also like having seamless access to and interop with a set of powerful ones that don't try to protect me from my own poor decisions. I shouldn't need to do extra work to make use of an alternative more powerful tool for a small part of a project. At that point it becomes very tempting to drop the safer tool altogether in favor of the more powerful one just to avoid the obviously needless and therefore particularly irritating overhead.

I much prefer the approach of providing limited language subsets that can be opted into and out of in a targeted manner. Having the compiler enforce a simple one by default provides a set of guard rails without getting in the way when it matters.

If I could write the majority of my code in something resembling Go and just a small bit of it in an alternative dialect with expressive power comparable to Common Lisp that would be ideal. To that end, I'm a huge fan of features like @system, @safe, and @nogc in D while very much disliking the need to use string mixins to write a DSL, the various restrictions placed on CTFE behavior, and other similar things.