LuaJIT is, by far, the best option for scripting in games/RT, thanks to the incredible JIT performance and its incremental GC with deadlines.
But there's something when you start playing with Lisp and then you want to keep using it more and more. Suddenly the classic Ruby/JS/Python/Lua language design feels boring and stale (ironically, given the age of Lisp).
After getting my feet wet in v2, I'm doubling down on Scheme for The Spatials v3, this time using S7 Scheme, a true gem of an interpreter (first class environments, hook on symbol-access for reactive programming, super extensive C FFI support, etc.)
Could anyone comment on the Lisp --> Racket mind-blowing experience? I have worked with Lisp and Clojure, and most of the big concepts are shared. What has racket on top of (common, I assume?) lisp?
It is simply that I found Racket to be the most pleasant and inviting to use. An all-in-one toolset, with a large and vigorously well documented standard library, and some of the best books on programming there are.
As a sometimes-aspiring language designer who'd already done one esolang before coming to Lisp, the language dev tools that Racket provides were also far too enticing to stay away from.
> What has racket on top of (common, I assume?) lisp?
Racket is from the Scheme family rather than the Common Lisp family, (Racket used to be PLT-Scheme before the name was changed because Racket isn't strictly an implementation of the Scheme standard, though it includes such an implementation among its bundled languages.)
Started coding in the mid-80's and went through a plethora of languages, OSes, frameworks, you name it. Learned ML when Caml Light was new and got a third price in logic programming contest between universities.
Nowadays I care mostly about JVM, .NET and first class languages from OS vendors.
Why? Not all of us have the luxury to move around just for working with the languages, or the skilled team, we would like to.
This is primarily why I'm focusing on strengthening my JavaScript skills...There are tons of start-ups looking for back and front-end devs. Your comment also makes me want to get back into Java and C#...I've taken the time to learn Haskell but I know realsitically I'll never get a Haskell job (at least here in Quebec...).
It's not that there is anything particularly special about what you can do in Lisp than what you can do in, say, C#. It's that Lisp provides facilities for metaprogramming that most other languages lack. Most other languages make metaprogramming hard enough, or require it all be done at runtime, that it is very discouraging against the concept in general. Lisp creates a culture around metaprogramming that fundamentally changes how you approach programming forever after.
You stop writing programs. You start writing programs that write programs. It's a lever that multiplies the power of the programmer. That can be both good and bad. For a hacker coding in earnest on her own, it can be extremely good.
Yes, if you are the type of beginner or intermediate programmer that still struggles to just write programs, advanced metaprogramming in any language is not for you. If you're an intermediate programmer looking to become an expert programmer, learn Lisp, where metaprogramming is easy, and take the lessons on to whatever other languages you eventually end up using.
I've never had to change my mind about Lisp -- but to me, Common Lisp's condition system kicks the crap out of every other language because it allows you to handle conditions without unwinding the stack.
And whenever you get dropped into the debugger, you can edit and reevaluate the broken code or values or whatever -- and then continue on with the task.
In other words, you can begin a task with imperfect code -- and refine it as you go along -- figuring out how to handle corner cases as you go. All without starting the task over from the beginning.
I know of only one other language that allows you to explore a problem space like that.
Besides, the parentheses make the code less jagged looking and jagged looking code imo, is more tiring to look at. Lisp is simply prettier.
Smalltalk also drops you into a debugger on an error, letting you inspect the state of the system, correct your code, and resume. Check out Pharo Smalltalk.
Smalltalk probably supports this as well, but what's cool about Common Lisp's condition system is that it doesn't depend on user interaction or debugger to work. Conditions let you separate the code making the decision about how to handle an error from actual error handling. The decision doesn't have to involve interactive debugger, you can have your code making the choice about which restart (unit of error handling code) to invoke. The common use case is that you install various restarts as you go down the call stack; then, when an exception happens, control goes up the stack until appropriate decision code, which selects restart, and control goes back down the call stack to the selected restart block.
It's an incredibly flexible system that makes exception handling much more useful.
Tcl I heard has string-based homoiconicity. Otherwise, I'm yet to see a proof you can get an actual, usable and not incredibly annoying macro system working without turning your language into a Lisp. People keep trying, but it's always some inelegant subset bolted onto the core syntax.
I love using Julia, but for me writing Julia macros came with a steeper learning curve than in Lisp / Scheme, due in part to the syntax. I kept wishing Julia was a layer on top of a Lisp, and that I can just write Lisp macros. (I know the parser is currently in Scheme, but you can't exploit that easily.)
I tend to end up writing `Expr` objects directly when I'm building larger macros as I find them much easier to reason about. It's clearly not as convenient/clean as Lisp though. (David Moon actually sent a PR last year to make hygiene much easier.. unfortunately it got stuck for a while, but the PR was recently rebased and hopefully will be merged eventually).
Regarding the learning curve: we rewrote the first half of the Metaprogramming section of the manual a few months ago to try to provide a more gradual introduction, especially for people without a Lisp background. Objectively I don't know if the change has helped, but I tell myself that the number of macro-related questions has gone down :)
We would really like to make these tools accessible to people both with and without a formal CS background (probably the majority of Julia users will fall in the latter category). So, if you have any suggestions for doc/pedagogy improvements in this area, I would be very happy to hear them!
We talk sometimes about having an additional reader to support another syntax ... but so far, it isn't something where someone's actually volunteered to step up and help. It'd be interesting to play with some ideas from David Moon's PLOT as well ...
Take a look at Converge, Nemerle, TH and many other similar languages - they're doing just fine without any homoiconicity. All you need is a decent quasiquotation.
Thanks for the pointers, I never heard of those languages before.
I am actually looking at the Converge documentation on macros now, and I found the perfect quote to highlight the problem I see with those approaches:
Quasi-quotes allow ITree's to be built using Converge's normal concrete syntax. Essentially a quasi-quoted expression evaluates to the ITree which represents the expression inside it. For example, whilst the raw Converge expression 4 + 2 prints 6 when evaluated, [| 4 + 2 |] evaluates to an ITree which prints out as 4 + 2. Thus the quasi-quote mechanism constructs an ITree directly from the users' input - the exact nature of the ITree is of immaterial to the casual ITree user, who need not know that the resulting ITree is structured along the lines of add(int(4), int(2)).
That is, quasi-quotes take some code and turn it into a tree object. This tree object can then somehow get compiled into actual code later. Compare that with Lisp approach, in which code is data. You don't think about the code as something separate from the tree that represents it. The code is the tree. There is no ITree object.
It may seem like just "semantics", but I find this to be a significant cognitive difference.
> Compare that with Lisp approach, in which code is data.
It's not any different. It does not matter if your `(,a ,b) is compiled into (list a b), or your ` \a\ = \b\` is compiled into make_binary('=',a,b) - both are constructors, essentially.
Sure it is. All parts of a Smalltalk program are present as objects that can be manipulated by sending them messages. Classes, methods, variable bindings, closures, stack frames, even individual messages are objects.
As a practical matter, methods also have a textual representation, but that's not strictly necessary. Ten or fifteen years ago, the Squeak method browser had a mode where you could write Smalltalk code using tiles, kind of like in Etoys, no parsing necessary. That was a hassle to use, though, so people stuck with writing methods using text.
By the way, Lisp has the same sort of "impurity". S-expressions are very simple, but they are syntax. It's surely possible to create a tool that would let one construct cons cells in memory directly, but that would be a hassle. Instead we use parentheses.
Maybe not the same, but I feel like nim (http://nim-lang.org/docs/manual.html#templates) can have a comparable power ot redefining itself. But I'm absolutely not an expert neither in any lisp nor in nim so I can't really tell.
After learning about Elixir (http://elixir-lang.org/) and playing with it some, I now want an Elixir job. (I'm skilled in Ruby, and Ruby already back in the day wanted me to get a Ruby job... which I finally did)
One nice thing about Elixir for Lisp lovers is that you get "real" macros (full AST access within a quoting context) AND actual syntax. I am not sure there are any other languages which feature that combination currently.
You get full AST access in Erlang as well. I don't know how it is in Elixir, but in Erlang you don't want to touch that feature with a ten foot pole. It's hairy and incredibly annoying to work with. I'm having a hard time to imagine how it couldn't be without homoiconicity and with that "actual syntax". I've been reading about macros in Scala recently, and they seem to suffer from the same problem - they just don't fit well with the rest of the language.
> but in Erlang you don't want to touch that feature with a ten foot pole. It's hairy and incredibly annoying to work with
It's pretty much the exact opposite in Elixir. The only thing you really have to wrap your head around is the switch between the quoting context and the unquoting context... which is pretty much no different from understanding macros period. The definition syntax looks just like a method definition, except it's "defmacro" instead of "def", and the macro body receives an AST instead of (or in addition to) your usual arguments. But I'm probably not doing it justice...
Yes, I was riffing on Lisp not really having a "syntax."
The fact that Erlang's syntax is (disclaimer: subjective) awful just adds further grist to the Elixir mill, assuming you think Elixir's syntax is (disclaimer: subjective) sweet.
Which a lot of people seem to be coming to the same conclusion on.
In Elixir, I have the full power of Lisp-level macros, in a functional immutable pattern-matching language, with a ridiculous level of concurrency (you can spawn a million or so processes in a second on your typical laptop), hot software upgradability (https://www.youtube.com/watch?v=96UzSHyp0F8 for a cool demo), access to the entire repository of already-existing battle-tested Erlang code...
... AND it's readable. :P
Lisp with its powerful macro facility has had literally dozens of years to find acceptance and still struggles (argumentum ad populum notwithstanding, a userbase with critical mass brings a plethora of other advantages). Ruby found enough of a niche that I think there is something to be said for Ruby's style of syntax. Elixir gives you both, and then some.
I was talking about Erlang and Elixir, not Lisp and Elixir. I don't need an introduction to Erlang/OTP, as I've used it for quite a while. You sound a lot like you're in the hyper-enthusiastic newbie phase, though.
I... guess I am. Is that OK? :) I like Erlang too... but I was one of the folks for whom the syntax turned me off originally. I can't explain why, especially if you're one of those developers (bless their pure-engineering hearts) who thinks syntax is irrelevant once you grok it. The best I can explain it is that some brains interpret computer code as a very abstract form of writing and some don't (or don't need to), and I may be one of the former, and that causes some syntaxes to "feel better" or "feel worse". It's... not very rational, sigh.
the thing i remember most from comp.lang.lisp was someone defining a truly great language as one that could get you to take a job simply to work with it, irrespective of the actual problem being worked on.
I once took a job working on a product I had a moral objection to -- on a platform I despise (windoze embedded) -- simply because I'd be working in Common Lisp.
Not OP, but I find this text a good introduction to one of the most significant things you can get enlightened by when learning Lisp: http://www.defmacro.org/ramblings/lisp.html.
Learning lisp is enlightening, but to claim that it's that much more productive than some of the other well designed languages is a stretch.
- Lisp macros are powerful, so the core of the language can be kept simple. However, many languages take an alternate approach and codify the most common programming patterns into their specification. The result is a compromise that works for the majority of cases, and better understood than custom macros.
- Homoiconicity is elegant, but somewhat over rated in practice. Declaratively expressing intent does not require homoiconicity, you can do that in JSON or XML if you agree on a format. Now with lisp, code being data, you can be infinitely more expressive; but at the same time inferring intent out of complex code-as-data is essentially writing a very intelligent macro/parser. There's a cost to it.
- if you're not really gathering the intent from code-as-data, there are ways to do eval() in other languages as well.
- Lisp has not succeeded on a relative scale. Let's not discount that.
- Compilers can optimize well known constructs better than equivalent macros in lisp.
So again, learning lisp is a great idea. But there isn't a one programming paradigm that's universally better than others.
- Lisp has not succeeded on a relative scale. Let's not discount that.
Is there a clear reason for this? I've only ever heard good things about lisp.
My impression, as a hobbyist programmer, is that lisp appeals to people who have a deep intellectual curiosity about the way programs work. It doesn't seem to appeal to the larger pool of programmers who are looking for a language thy can pick up in a straightforward way so thy can either get a job, or build a project they've been thinking of.
I fell in love with Lisps and FP precisely because they were an easier, more straightforward way of just getting the job done than the alternative.
How many times have you written a dozen lines of for-loop that could've been one map/reduce? How many times have you written a whole page of Object { this.foo = ... } just to add the simplest of new features?
Literally the reason I got out of programming after high school almost 15 years ago and wrote it off as 'not for me' was that kind of tedium, and learning Lisp and FP were the point in my return when I said 'Oh, wait, actually this is pretty great; where the hell was this when I was a kid?'
Lisp didn't take off because 1) home-computer-ready implementations were largely out of reach for three decades, and 2) Lisp and FP both were embracing the importance of expressive power during an era in which most programming still worshiped doing things the hardest way possible. Shit, when I was a kid, you weren't a 'real programmer' unless you did everything in assembly. Then it was C above all, to be followed by EnterpriseFactoryJavaFactoryFactories.
By the standards of most of the programming world, where there are still real bosses who grade coder performance in KLOC, Lisp is 'wrong'. But pumping out thousands of lines of repetitive boilerplate is not equal to efficiency, it just looks like it to a work culture that only understands output of work rather than quality of work. If programmer A takes 1 hour to solve the problem with 100 LOC, and programmer B thinks for 45 minutes and then solves the same problem with 4, who's the most efficient in that scenario?
And more to the point, which of those two work environments do you want to sign on for?
Same here, I never understood Java interfaces, abstract classes, and a ton of other "features" but picking up Clojure was a breeze. I don't understand why complicating thing that supposed to be simple helps you by any mean. On the top of that, I have seen several cases when Java programmers tipped over in their own code because of the complexity that they thought they understand, except there was a particular case when it was doing something else then expected.
Reasoning about Clojure (LISP) code is always easy because if you follow best practices you have small functions with very little context to understand.
On the top of these, I see the ratio of LOC 50:1 (worst case even higher) for Java : Clojure code that does the same thing. Usually people get triggered and say why does it matter, but in reality less code is better for everybody. Easier to understand, less chance of errors, etc. Correctness was long time lost for majority of Java developers, just put out a survey and you can see it for yourself.
It is also pretty common practice not to handle exceptions well and just let a DNS not found error explode as an IOexception and good luck tracking down what caused it (literary happened to me).
I understand that the average Java dev does not see any value in LISP (Clojure) but it silly to expect that the average of any group is going to lead the scientific advancement of any field including computer science.
One tendency that you can see if you are walking around with open eyes that the people who spent significant time in developing procedural code in an imperative language understand the importance of functional language features and the power of LISP. One can pretend it does not matter see you in 5-10 years and see how much this changes.
I would imagine not, though the parent can speak for himself. I agree with what has been said before, that Go is a bold step backwards, just another language to replace large amounts of Legacy Enterprise Code with (sometimes) slightly less large amounts of (Soon To Be Legacy) Enterprise Code. Go has going for it corporate backing and a good community, but on the technical merits alone, there is a better language for every task.
I don't know about "very", but it's pretty verbose and very imperative. You have to do a lot of repetition, often straight up code copy+pasting, in some cases.
In a way it's similar to frameworks. Frameworks which are more popular try to make choices for the user (like Rails). As an end-user I clearly wanna focus on my tasks, rather than choosing a toolset or perhaps building one myself.
Lisp is minimal and abstract. That's appealing to a different set of people, who aren't satisfied with off-the-shelf abstraction levels. It's also fun and challenging to work at that level, though IMO it's not always going to translate to better productivity.
For me, learning assembly and going through the 80386 reference manuals were more rewarding in terms of understanding how programs work. Sorry I have no specific insight to offer on the question you asked.
When AI couldn't live up to the hype, funding dried up. A lot of that funding was driving the companies and research projects that were doing major Lisp development. After the AI Winter, Lisp was strongly associated with the unmet promises of AI and thus gained a reputation as a poor choice for serious projects.
Around 2000 a new generation rediscovered Lisp. SBCL was released in dec 1999. CMUCL rethought with a simplified implementation and build process. From then on various implementations were improved. Clozure CL was released on multiple platforms. The commercial Lisps were moving to the then important operating systems and architectures.
The hype moved to Clojure, Racket, Julia and other Lisp-like languages. The core Lisp may not have the same depth of commercial activity as in the 80s, but generally the implementations are in the best shape since two decades. There are still lots of open issues, but from the Lisp programmer standpoint, it's an incredible time.
lisp makes you an asshole programmer. you're encouraged and enabled to write your own language for each problem, thus isolating you in a world of your own views and ideas. it's a babelian tar pit, luring programmers to their doom.
being your own tin pot dictator is quite alluring. you get to go to great feats and neat hacks to get code working. to control and manipulate the code to allow you to write what you want. every new macro and construct shapes the product in your own image and ideals, subsequently alienating other programmers.
it's like these language revisionist cranks who want to replace english with their own little concoction that's just ever so perfect and logical. a complete ignorance of social factors.
anecdotally, I know of large scale codebases and products in simpler, less elegant languages, meanwhile lisp seems to be popular with the lone hacker aesthetic.
eventually, with enough practice, you get to the smug lisp asshole stage.
this is where you wonder why lisp is unpopular, or fragmented, but assume that it's simply too good for the populace. Classics like 'worse is better' struggle with the notion that lisp maybe isn't that good. Sometimes you get a naggum complex and trot out saphir-whorf. Other people are terrible and that is why they don't use lisp.
it can't be that lisp isn't a great idea. or macros aren't a great tradeoff. at least the ruby community is coming to terms with monkey patching coming at the expense of library conflicts.
lisp is a strange beast. a simple tool that encourages complexity. purity over utility. a perfect goo waiting for the next hero to shape it and return to the mortal plain with their new, perfect macros.
Maybe that's why I like Lisp so much. Because "social factors" are so frikkin' annoying and irrelevant and I feel the world would be so much better for everyone if we stopped paying so much attention to them as we do now.
To formulate this a little more nicely, I might say instead that there is a real need for "intimate" languages, just as there is a need for "collaborative" languages.
As an example, the shells on my personal machines are often customized beyond the comprehension of anyone who isn't me, with tons of two-letter aliases and bash functions, cryptic environment variables, and a $PATH that's several terminal lines long, filled with labrythine symlinks and oneliners that I've accumulated over the years. Many people have similarly elaborate and impenetrable emacs configurations.
That's fine, since this is my personal environment, but at work (I'm a sysadmin, more or less) I'm still able to use more-or-less bash, and even write portable shell scripts that eschew bash-isms. Similarly, all that horrible e-lisp powering super-personalized workflows doesn't prevent someone from writing an emacs mode that they can share with others, the point being that a language that enables customization is great, because you can always just not do that and write code that others will find comprehensible.
Conversely, if your language forces you to write in a collaborative style, you can't gain efficiencies in your private use of it.
> To formulate this a little more nicely, I might say instead that there is a real need for "intimate" languages, just as there is a need for "collaborative" languages.
That's a... way of putting it I've never seen before. I'll remember the concept of "intimate" vs. "collaborative" language for the future.
Personally, even though I write a lot of Lisp and live inside Emacs, my environment seems to be quite... standard. The "collaborative" mindset is emphasized in pretty much every programming book out there, and I must have acquired this kind of weird fear of overcustomizing my environment thanks to it.
My naive reasoning of why is that a lot of people start by learning c-like languages and don't see the need to learn something as different as lisp. As lisp and it's descendants were never really the dominant language, it was never the first type of language most people learned. Now that many mainstream languages have progress to incorporate more and more lisp features, it's becoming less foreign to many devs and the popularity is increasing and is now higher than I think it ever was.
>> Lisp has not succeeded on a relative scale. Let's not discount that.
> Is there a clear reason for this?
Yes. In the 1980s AI was teh new shiny and at that time, Lisp was almost synonymous with AI.
A bunch of people over-promised when it came to AI and expert systems, and failed to deliver. And people conflated the failure of the promise of AI with the failure of Lisp. Essentially, guilt by association -- people can be dumb that way.
Amusingly, once something in the realm of AI actually works -- we stop calling it AI. But one thing is for certain: the scruffies have been right more often than the neats.
Lisp macros are powerful, so the core of the language can be kept simple. However, many languages take an alternate approach and codify the most common programming patterns into their specification. The result is a compromise that works for the majority of cases, and better understood than custom macros.
The semantic core is kept simple. That doesn't mean lisps don't provide constructs for common patterns. Ej. Loop, with-open-file or defclass or Racket's for/ constructs.
Plus a good written macro is easy to understand and I'd argue most of macros are good written. In fact I'd like to see a macro that what it does is unclear on a widely use liso library.
> - Compilers can optimize well known constructs better than equivalent macros in lisp.
Lookup compiler macros. Macros can help the compiler optimize the code.
99% of programming works like this: you pass parameters to a function/macro. If you screw up, the compiler spits an error. The details of the error message are rarely relevant, you mostly know what's wrong even before you read that message anyway.
This whole talk about macros being crazy dangerous and difficult is very misguided. Most of the time, if a Lisp compiler spits a weird message on you, you know what you've screwed up. In the 1% cases you don't, you apply macroexpand-1 (or equivalent), see why the expansion doesn't make sense and fix it. In the 1% of the cases it doesn't help, you keep reading the source until you understand what's wrong. It's no different than debugging functions. Same rules apply.
> there isn't a one programming paradigm that's universally better than others.
That's so true. I wish someone would come up with a language where a wide variety of programming paradigms, including imperative, functional, and message passing styles, could find convenient expression.
EDIT: This comment is almost an exact quote from somewhere. Bonus points to whoever can identify where.
The parent's humorous wish is granted by the wizards of MIT Scheme (and, I daresay, even more fulfilled by Racket):
"Scheme is a statically scoped and properly tail-recursive dialect of the Lisp programming language invented by Guy Lewis Steele Jr. and Gerald Jay Sussman. It was designed to have an exceptionally clear and simple semantics and few different ways to form expressions. A wide variety of programming paradigms, including imperative, functional, and message passing styles, find convenient expression in Scheme."
> and an AST with a representation that is similar to Lisp
That's actually cheating, you know :). Lisp pretty much is AST. It's a fun fact about Erlang that it's not directly compiled to BEAM, but is first translated into a very strange, almost lovecraftian Lisp. I've worked with Erlang commercially for some time and ever since learning about parse transforms I kept wondering why they didn't just clean up the "intermediate language" syntax; they'd have a decent Lisp instead of a parallel Prolog.
Also: writing good macros is (even) more diffcult than writing good functions or modules.
Writing macros is doing language design and compiler implementation at the same time.
If you've ever cursed the error messages from a C++ compiler, think how much worse it would be if that compiler was written by your co-worker part-time as a side effect of writing rest of the code.
(I wrote clojure in anger for three years with brilliant co-workers)
> If you've ever cursed the error messages from a C++ compiler, think how much worse it would be if that compiler was written by your co-worker part-time as a side effect of writing rest of the code.
This is why you use proper facilities to write macros, that will enable you to forge better error messages than most C compilers. This is also why you don't simply use something like `defmacro` that will not let you supply syntactic information (syntax objects) with location and context information.
A good macro has a contract that constrains its use and inform you when you're breaking it, so that you don't have to rely on your coworkers to explain their macro to you.
See this[0][1] for a very detailed view on how you can provide the programmer with the tools they need to create abstractions that stretch well into the world of macros and still be able to make them usable.
You can set enforcable conditions for your macros to guide people, just like any language can statically check their syntax.
This is not an unsolved problem. What is unsolved, like many people have mentioned, is when the culture of a language (and the facilities of lesser languages) don't emphasize managing macros like other abstractions.
Using Lisps that don't emphasize more than "Macros are functions that modify lists of syntax at read time" will lead people to believe that's all there is to it. You won't have to be angry about macros if you use a language that gives people the tools to help you use them and then fosters that idea.
No. Writing macros is less difficult than pretty much anything else. You just have to follow the proper methods.
Macros are, essentially, compilers. It is a very well studied area, writing compilers is a totally mechanical thing which does not require any creative thinking.
Compilers are best implemented if split into long sequences of very trivial tree rewrites (see the Nanopass framework for an example of this approach). Such tree rewrites should be declarative, and you don't really need a Turing-complete language to do this. This approach is inherently modular and highly self-documenting, so you're ending up with nicely organised, readable, maintainable code, much better than whatever you'd do with plain functions.
> However, many languages take an alternate approach and codify the most common programming patterns into their specification. The result is a compromise that works for the majority of cases, and better understood than custom macros.
That's not the case in my experience. It's very easy to look up the definition of a macro, or see what the macro-expansion of an expression looks like. Good luck trying to figure out what your interpreter/compiler/JIT is actually doing when the language documentation is lacking.
For Common Lisp at least the quality of documentation is also another huge advantage over any other language I've used - the Hyperspec (http://clhs.lisp.se/) is extremely detailed, concise, and easy to access (you can pull up the documentation page for a particular symbol with a keystroke, or browse through the index or by TOC when you aren't sure what you are looking for).
> Homoiconicity is elegant, but somewhat over rated in practice. Declaratively expressing intent does not require homoiconicity, you can do that in JSON or XML if you agree on a format. Now with lisp, code being data, you can be infinitely more expressive; but at the same time inferring intent out of complex code-as-data is essentially writing a very intelligent macro/parser. There's a cost to it.
Except that doing it with JSON or XML is usually two orders of magnitude more code than a macro solution would be. Now simple problems that could have been debugged with a macroexpand involve tens of thousands of lines of parser libraries (it's 2015, why are encoding errors still an issue for anyone?), ConfigurationFactories and class hierarchies for the internal representation of whatever it is you are trying to encode in JSON, and glue code to connect it to your current controller and model classes.
> Compilers can optimize well known constructs better than equivalent macros in lisp.
Compilers are very limited in the partial evaluation and domain-specific optimizations that they can do. This is not the case for macros.
> But there isn't a one programming paradigm that's universally better than others.
That's kind of the point of macros - to allow you to add new programming paradigms without having to change the base language or compiler.
> LuaJIT is, by far, the best option for scripting in games/RT
Much as we want to like it, we've been frustrated by Lua for a single reason: no preemptive threading library. Its lack of true prototype-style OO is more than a bit annoying too.
Well, I guess that's not really fair. Obviously you can implement prototype-style OO, more or less, using the metatable and metamethod facilities. But as an old NewtonScript developer, I rather find
foo = { x = 1, y = 2 }
mt = { __index = bar }
setmetatable(foo, mt)
to be crazy compared to
foo := { _proto: bar, x: 1, y: 2 }
The uncleanliness of function declarations in Lua compared to NewtonScript also gets to me in this way. At any rate, to me, the metatable facility feels like a hack. That's not to denigrate it: it's a very flexible and clever gizmo which can be used for a variety of cool things. But to me proto-style OO languages are notable for their elegance and simplicity, and metatables expose a fair bit of wiring and boilerplate. [It also wasn't a good sign that the whole OO section in "Programming in Lua" was about "classes" :-( ]
I've looked into both l2l and moonlisp and they were too incomplete to be usable in their current state, and not being worked upon recently (or not much). The most current and interesting effort in this area in my opinion is Conspire[1], which is actually based on Terra[2], another amazing piece of software.
The decision to not go with LuaJIT was complicated and depending how it goes with S7 I probably won't take it again for a new game. For starters I doubt I will delegate any per-frame non-evented computation to the S7 side, while I could easily do it in LuaJIT. But I'm already seeing an at least 10:1 ratio of lines of code for things like building GUIs, and it's only going down even further now that I'm implementing event callbacks with lambdas and adding reactive-like system for rendering updates.
Good work on hua! I read somewhere that once you learn a Lisp you are destined to write one. I've been tempted too :)
But there's something when you start playing with Lisp and then you want to keep using it more and more. Suddenly the classic Ruby/JS/Python/Lua language design feels boring and stale (ironically, given the age of Lisp).
After getting my feet wet in v2, I'm doubling down on Scheme for The Spatials v3, this time using S7 Scheme, a true gem of an interpreter (first class environments, hook on symbol-access for reactive programming, super extensive C FFI support, etc.)