I think the whole enlightenment thing w.r.t. lisp is overblown.
A recent example from personal use is continuations. Scheme has them as a first-class object. Common Lisp does not, but a common claim is that you can write macros to provide continuations. Some people have: there's "cl-cont" available on Quicklisp, which is a macro that will code-walk your functions to turn them into continuation-passing style and thus allow you to use continuations in those functions.
So that's great, right? Common Lisp now totally has continuations? Not at all. In order to get this feature, you need to wrap ahead of time (specifically, at compile time) the functions you want to be continuable, and all of their callers, in this macro. You cannot simply use a function that you've been given as part of a continuation, it had to have been compiled under this macro.
That's where the power of macros completely falls down and, in my opinion, gets completely overblown. Yes, your language is extendable, but your extensions are limited to computation and source-to-source transformation at compile time. You can't apply any of that power to already-existing artifacts.
Which is not surprising. Actually nobody with a clue makes such a claim.
Still, Lisp macros have a wide variety of very useful applications.
> Yes, your language is extendable, but your extensions are limited to computation and source-to-source transformation at compile time.
Still quite useful. From relatively simple stuff which makes to code more readable to complex macros like ITERATE.
> Which is not surprising. Actually nobody with a clue makes such a claim.
Most Lisp books make this claim.
For sure not.
1. lisp got a lot of stuff wrong; there's really no reason not to use scheme.
2. lisp syntax is more something to overcome than something to become "enlightened" about. Language syntax no longer has to be motivated by ease of parsing.
3. Dynamic typing only gets so enlightening. At the end of the day, type theories are where the rubber hits the road.
4. Macros don't excite me much. I mean, they're cool, sure. Okay.
At the end of the day, there's a lot more exciting stuff out there (e.g. any math class beyond the calculus sequence or so) that people get way less worked up about.
It's possible to understand lisp, think that there are important ideas there, but not go around evangelizing. Most smart people who study something non-trivial don't evangelize.
Scheme got a lot wrong from a practical perspective. Use Lisp instead.
Type theories are over-hyped. 99.99% of all software is written in languages without advanced type systems.
Macros are nothing for 'excitement'. They are a tool. They enable the user to write source transformations, which has several applications in Lisp: control structures, compile-time computation, etc etc.
But Im not going to get into a language war.
Stepping back to the original point, there are other significantly important/powerful ideas in the world, and lisp users are somewhat over-the-top in their significance-to-hype ratio.
> Stepping back to the original point, there are other significantly important/powerful ideas in the world, and lisp users are somewhat over-the-top in their significance-to-hype ratio.
Many of the powerful ideas in software development are available in Lisp.
And there's a whole hell of a lot more in the world than software development...
To the extent that lisp captures any of these other foundational ideas/theories/techniques, type theory does better (which is what I was pre-empting with my original reference, not the role of type systems in the world of practical software development).
Lisp is not a version of lambda calculus. It's a programming language. Macro programming in Lisp works fine in many cases.
> type theory does better ... not the role of type systems in the world of practical software development).
Lisp is about practical software development.
I'd argue that there are lots of other settings with ideas a powerful or more powerful than whatever it is each individual evangelist feels someone should get out a lisp. Yet none of these other things have enlightened evangelists pushing the product.
That's all I'm saying.