Is Lisp still useful in today's world? (2011)

http://programmers.stackexchange.com/questions/55284/is-lisp-still-useful-in-todays-world-which-version-is-most-used

by cpleppert • 13 years ago

50 59 13 years ago

programmers.stackexchange.com

mindstab3• 13 years ago

Learning to program in lisp (specifically reading Practical Common Lisp [http://www.gigamonkeys.com/book/]) has made me a better programmer in all other languages even if I don't really use Lisp. Even my friends/coworkers have noticed it when coding together. My style is forever improved.

Learning Lisp just seems to promote better ways of tackling programming problems that is transferable to other languages where it's not as encouraged naturally even if superior.

monkeyfacebag2• 13 years ago

Completely agree that learning functional programming has improved my thinking and code. The one difficulty I continue to encounter is switching back and forth between recursive and iterative thinking. From a computational perspective they may be equivalent, but from a cognitive perspective they aren't (at least in my case). I don't know how many times, for example, I've been bitten by a stack overflow when jumping into Python from Haskell (or equivalently, jumping directly into the ST Monad because I want to iterate through some lists).

pavelludiq7• 13 years ago

I've been using Common Lisp for two years now, I've written exactly ONE recursive function that wasn't an exercise or an example. Functional interfaces to functions with local state in loops? What exactly is wrong with that?

For example it is my opinion that this function is in no ways inferior to a recursive equivalent:

  (defun range (end &key (start 0) (step 1))
    (loop for i from start to end by step
      collect i))

Quarrelsome• 13 years ago

After reading up on lisp and associated topics (purity mainly) I rewrote a component in our C# code base and made it magnitudes of order more stable and atomic.

I hadn't written a line of lisp (although counted many brackets when trying to read along) but just studying it helped me think about programming problems a bit differently.

xyzzy123• 13 years ago

Yep! My joke is that "Practical Common Lisp" is the best Javascript book ever written ;)

RyanMcGreal• 13 years ago

"Lisp is worth learning for the profound enlightenment experience you will have when you finally get it; that experience will make you a better programmer for the rest of your days, even if you never actually use Lisp itself a lot."

-- Eric S. Raymond

gruseom2• 13 years ago

If we're quoting that then we should also quote PG's objection to it: if Lisp makes you so much better a programmer, why wouldn't you want to keep using it?

duaneb• 13 years ago

THe only thing that really distinguishes lisp these days (IMHO) is its macros. However, I think there are better languages out there to learn any particular paradigm-Python/Java for OO, Haskell/Erlang for functional, C for procedural, Ruby/Python for dynamic & duck typing, etc.

Lisp is great if you need a compiler tomorrow. If you have the time, though, I think that other languages are better when there's more time to invest.

EDIT: To actually answer the question, of course it's still relevant and useful, but perhaps other languages have caught up. It's still used in industry (Google uses it via ITA, IIRC).

bcoates2• 13 years ago

Multi-methods are still scarce among languages with OO features, and it's a big hassle working around that shortcoming. There's probably more gems in CLOS that haven't made it out into the mainstream yet.

BruceM• 13 years ago

Multimethods and the condition system are 2 of my favorite things.

monkeyfacebag2• 13 years ago

It's not clear to me what Python the language offers over the Lisp family, other than improved readability for some class of users and translation to and from pseudocode (see Peter Norvig's comment in 2010: http://news.ycombinator.com/item?id=1803351 ). These aren't necessarily small advantages, but neither do they mitigate Lisp's power and flexibility. I do, however, think Python the community offers a lot of practical advantages to the new user over, say, any particular Lisp community.

TylerE3• 13 years ago

A high quality reference implementation. This is, in fact, a trait shared with pretty much every other language to gain traction in the last 20 years. In Lisp, there is substantial fragmentation on how do things like GUI and Networking, and often no clear winner. SBCL seems to be the de-facto FOSS implantation, but Allegro is the leading commercial vendor.

pavelludiq7• 13 years ago

CLOS and MOP, read-write consistency, restartable exceptions, reader macros, optional typing, many high-quality implementations(including several commercial ones that come with excellent support), high-quality standard document, probably still the fastest dynamic language around, superb introspection support, one of the best interactive work-flows, surpassed only by smalltalk, DECADES of being tried and used in every conceivable industry and application, from super computers, space probes and AI, to web apps, games and prototyping(you'd be surprised how much software was prototyped first in lisp).

AAAAAND macros too, I guess. They are nice.

</smuglispweeniecomment>

juan_juarez2• 13 years ago

> commercial ones that come with excellent support

Maybe I'm just too small-time for it to matter but what, exactly, does this commercial support actually buy you? In the last 10 years of programming, I've only run into a handful of bugs in my tools. When dealing with OSS projects, they were already known and fixed in newer versions. When dealing with $BIG_DATABASE_COMPANY they told me to use a workaround and didn't fix the bug until the next major release of the software.

I don't have a problem paying for commercial software, I understand it supports development and improvement of the tools, but what exactly are you getting when you spend (tens or hundreds) of thousands of dollars on licencing costs for support?

pjungwir4• 13 years ago

I'm not a Lisp guy, but the amazing thing I see in Lisp that is missing from other languages is that due to the extremely simple syntax, code is data and data is code. That lets you do some amazing things (Cf. SICP).

On the other hand, isn't one lesson from modern computing that treating data as code is really dangerous? I have yet to see this addressed by Lisp advocates.

skylan_q• 13 years ago

The way in which code is modified in Lisp is generally in the source code itself, and overtly in the run-time environment or binaries. The latter might be what you're alluding to.

Allowing code to be treated as data is a very powerful thing when it comes to programming. But of course, with more power there is more danger.

pavelludiq7• 13 years ago

Define dangerous? Are you concerned with security? In which case, don't eval untrusted code, and you're fine.

Maintainability? If done right "code is data" could improve the maintainability, or decrease it drastically, just like any other feature. If you have 80 lines of comments for every 10 lines of code, you've decreased your maintainability, comments are dangerous by that logic.

betterunix5• 13 years ago

Code as data is dangerous, sure, but:

1. Python, Perl, Ruby, and even Java have support for code as data. If this makes Lisp a risky language, then you should be very worried about all of the above.

2. It is easier to disable code-as-data primitives (eval for example) than it is to add them to a language that lacks such support. I use Lisp for code that is not public-facing; the ability to extend the program at runtime can be very useful when security is not an issue. Languages that lack support for such things are harder to work with for cases like mine.

3. Code-as-data in Lisp is primarily a compile time feature, not a run time feature. Most Lisp programmers are using this feature via the macro system, rather than having programs that compute new functionality based on their inputs. You can disable all runtime support for treating code as data, and still take advantage of it at compile time.

richeyrw• 13 years ago

Is Plato still useful in today's world? I think if you answer that then you should be able to give a a minimum a qualified "yes" to the question about Lisp.

dschiptsov4• 13 years ago

Not sure about Plato, I would rather say Buddha.)

IvyMike• 13 years ago

I was introduced to both Lisp and PLATO in 1992 at UIUC. I was very confused by statement until I realized you meant Plato, not PLATO, which has very little use in today's world.

https://en.wikipedia.org/wiki/PLATO_(computer_system)

dschiptsov4• 13 years ago

This. Very. Site.

chc• 13 years ago

I'm not so sure that's a good example. It seems to me that PG had a Lisp he'd created for his own gratification and Hacker News was a good chance to try it out in the real world. It's hard to imagine Hacker News would have suffered if Arc hadn't been ready yet and he'd been forced to use Django or something. I think HN helped Arc more than vice-versa.

dschiptsov4• 13 years ago

The point is that he (with mr. Morris, I suppose) made this site quickly, cheap and are able to evolve it on the go, almost without downtime with help of very few people.

Another point is that this site is the proof of an approach to software development described in the On Lisp book. So, it is not a gratification, it is just a real-world project they have done for themselves to make money. It is not some showcase or a demo, it is real thing.

In case of Django, I think, it will require much more man-hours for building and maintaining and more resources (cost) to run.

This is an example of Less is More principle in action: less code (the core language concept) and, as a consequence, less everything - time, people, money.

Lisp isn't just a language with parenthesis. It is a whole philosophy (a multi-paradigm language). Well, better to read On Lisp.

nialo• 13 years ago

PG says in several of the Arc essays that HN exists because he found that programming languages turned out better when their creators worked on the language and some problem being solved in that language together. HN exists because he needed an application to force Arc to be better.

juan_juarez2• 13 years ago

I hate to break it to you but HN is not a great site because of it's implementation. HN's value lies in the content and community. If somebody other than PG launched an identical site today, nobody would even bother making an account.

dschiptsov4• 13 years ago

Its greatness is in that it's good-enough

base698• 13 years ago

If you are a JavaScript, Ruby, Python programmer it will teach you where first, rest, map, reduce, partial, apply, and a slew of other methods came and what functional programming is. It also has the side effect of teaching you how machines work at a low level (if you follow the SICP) with "environments" and frames. If you are a Java or .NET developer you'll pick up functional techniques and understand the origins of the object model. That's not even getting into macros, which basically are runtime code that writes code. I'm not aware of another language that has lisp style macros.

Ultimately it will help you be a better programmer even if you don't at first see the benefit.

gre• 13 years ago

* Most raw code written

So there are 20,000+ red-black binary tree implementations in Scheme. Great?

graycat• 13 years ago

Sorry, but my view of what is really "useful in today's world" is what the language has that makes it easy to get at, i.e., make use of, other software, e.g., TCP/IP, device drivers, operating system services, authentication services, APIs, something old written in Algol, Cobol, Folderol, Fortran, C/C++, etc.

Actually there is a theme that a language can be interpretive and, really, still fast enough if mostly it is used just as thin glue to connect other, efficient software where nearly all the time goes. E.g., IBM's in-house mainframes on their VNET were long run heavily with just their interpretive language Rexx: VNET was a little like the Internet except the network was less smart and the computers also played the role of routers. At one time IBM had 3600 such mainframes around the world. I've been using Rexx on Windows as a scripting language and want to convert to PowerShell due to the better access to Windows services.

rdmckenzie• 13 years ago

Speaking as a Lisper, I have to admit that this is an open question for me. On the one hand, the needs of parallel systems and state management offered by functional languages stands to bring Lisps (Clojure, Common Lisp etc) and other languages like Erlang ever more attention as we programmers attempt to manage the complexities of multicore design and distributed systems.

As a systems programming language I think that lisp has utterly failed. The Lisp machines are dead for various reasons (which I'm researching right now as a side-project) and to the best of my knowledge compiled lisp has clearly not taken the place of C in building operating systems (although I hope to do exactly that as does the author of [http://www.loper-os.org/]).

All of this comes down to an individual's definition of utility. Lisp is by definition of Turing Completeness just as capable as any other language you may wish to name, but with the usual Turing Tarpit or small language warning that you may have to roll your own. My perception, and one which several posts here on HN has affirmed is that traditionally Lisp was used by lone AI researchers who needed the power to roll their own anything quickly and efficiently. As a result of this "roll my own" mentality and simple lack of the internet (it was early and mid 1980s or so) libraries and SDKs as we know them were never built for Lisp systems.

Another difficulty is that as several other comments note there is no "one true" standard for Lisp. There is Scheme (which has official specs), there is ANSI Common Lisp which is a spec upon which several implementations have been based, and then there are countless other DIY and nonstandard lisps which elect to use different function names and otherwise make code non-trivially portable between lisp implementations. Not having a clear standard didn't help the lack of a library ecosystem at all, but some dialects such as Common Lisp and Clojure seem to be developing workable community library ecosystems. Of late Common Lisp has grown a library structure via ASDF code loading tool and the Quicklisp package manager, but Clojure is the only lisp I've ever encountered that really made any effort at all in the direction of providing native support for packaged libraries. The Clojure language includes syntax designed for allowing one file to explicitly state and "require" code in other files or even other libraries: a feature which is lacking from the Common Lisp standard. Thanks to technomancy's Leiningen tool and the clojars repository Clojure has a user-created system similar to Quicklisp + ASDF but trading ASDF's search path idiosyncrasies for a search path structure which should be familiar (or at least unsurprising) to Java developers.

TL;DR / Conclusion

If your boss comes to you and asks you to write a webpage, Lisp is probably not what you turn to. Could you? Sure, <shamelessplug> my blog is built in Clojure [http://arrdem.com].</shamelessplug> [http://refheap.com] is built in Clojure. [http://www.chris-granger.com/] is (presumably) Clojure. I know I've seen blogs in Common Lisp and other dialects but URLs escape me. Your boss says "Access the database", there are Clojure (okay fine Java but there is no real difference) libraries for SQL, MongoDB, Cassandra and more. Common Lisp also has SQL and MongoDB libraries. In short, while there is value in Lisp it is (for the time) not practically greater than the value of any other language despite the elegance of the functional approach and the power of the macro system. Hence its failure thus far to take over the world. However that same value proposition is improving as the CL and Clojure communities create and publish ever more libraries leading me to hope that Lisp may indeed take over the world one day.

Is Lisp still useful in today's world? (2011)

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