How Lisp is Going to Save the World • Hacker News Board

Re: How Lisp is Going to Save the World

#121

Post by chc » Wed, Jan 09, 2013, 7:22 PM UTC

david927 wrote: post #16

With the deepest reverence to John McCarthy, I regret to say that Lisp is our cosmological constant. It creates a static universe that is otherwise expanding; it reduces the problem to a solvable one and then declares victory. The truth is, it's all state. All of it. Remember that movie "Boy in the Plastic Bubble," about a boy with an immune system deficiency who lives instead a hermetically-sealed, sterile bubble? T…

You're making an extremely vague but bombastic claim here. I don't think you're intentionally trolling, but it operates on a very similar level.

What does this mean in practical terms? What are you specifically criticizing? It's obvious that you're taking some kind of dig at functional programming, but what is the actual critique or logical argument you're attempting to make here? It is very unclear.

Re: How Lisp is Going to Save the World

#122

Post by chc » Wed, Jan 09, 2013, 7:25 PM UTC

slurry wrote: post #65

david927 wrote: post #16

With the deepest reverence to John McCarthy, I regret to say that Lisp is our cosmological constant. It creates a static universe that is otherwise expanding; it reduces the problem to a solvable one and then declares victory. The truth is, it's all state. All of it. Remember that movie "Boy in the Plastic Bubble," about a boy with an immune system deficiency who lives instead a hermetically-sealed, sterile bubble? T…

Funny you should say that: just yesterday Reddit informed me that Lisp is 100% imperative because it has a loop keyword and allows destructive assignment.

Well, "Lisp" is a language family rather than a specific language. Although it's culturally drawn toward functional programming, Common Lisp is more or less an imperative language with first-class functions, much like Python is. Its designers chose this approach because they wanted it to be a "big tent" language that imposes few opinions on the programmer. Other Lisps like Clojure and Racket went in a different direction.

Re: How Lisp is Going to Save the World

#123

Post by jeffdavis » Wed, Jan 09, 2013, 7:28 PM UTC

martinced wrote: post #85

david927 wrote: post #16

With the deepest reverence to John McCarthy, I regret to say that Lisp is our cosmological constant. It creates a static universe that is otherwise expanding; it reduces the problem to a solvable one and then declares victory. The truth is, it's all state. All of it. Remember that movie "Boy in the Plastic Bubble," about a boy with an immune system deficiency who lives instead a hermetically-sealed, sterile bubble? T…

"The truth is, it's all state. All of it." The problem is not state. The problem is being able to recreate the state: both for testing and for business purposes. The bigger problem is that most programmers, like you, are knee-jerking before the issue of "recreating the state" and declaring that "It cannot be done, because it's all state" . And hence we have both languages who are build by considering mutability to be…

A CRA DB is essentially a SQL database with temporal capability.

Even if you have perfect time-warping capabilities, there are still big challenges to solving bugs with that kind of analysis. The time the bug is noticed may be long after the root cause, and working backward could be a very slow process.

That's why SQL has declarative constraints, to try to make the error noticed at a time closer to the root cause.

Would I like full time-warping capabilities sometimes? Of course. But it's just one more option, and a very expensive one at that. To be any use at all, we'd need to be able to warp backwards through the entire OS and its scheduling decisions (not just a single process), because many difficult bugs involve race conditions.

Really, we need better temporal capabilities, and more declarative constraints (that are immune from race conditions, like a UNIQUE constraint), better ways of avoiding race conditions, etc.; and they all need to work together.

That's why I have worked on temporal capabilities[1] as well as declarative constraints [2] (immune from races) in Postgres. Also, you might be interested in truly serializable transactions in postgres, which eliminate race conditions between transactions without blocking[3].

I feel like the programming language community should work more with the database community. From the article, they mention how restarts can help recover from errors encountered after part of the state has already been changed. But that kind of recovery is taken for granted with the atomic nature of transactions in a database. Database theory is largely about detecting, containing, mitigating, recovering from, and preventing errors[4].

[1] http://www.postgresql.org/docs/9.2/static/rangetypes.html [2] http://www.postgresql.org/docs/current/static/sql-createtabl... [3] http://drkp.net/drkp/papers/ssi-vldb12.pdf [4] http://thoughts.davisjeff.com/2009/12/23/good-error-recovery...

Re: How Lisp is Going to Save the World

#124

Post by mbesto » Wed, Jan 09, 2013, 7:31 PM UTC

smartial_arts wrote: post #21

hayksaakian wrote: post #17

Earlier quoted context omitted.

Was that with the intent of baiting clicks, or as satire?

Neither - I cannot measure how many times it gets clicked, since it's not my website, and I didn't really mean it in the satirical sense. I guess I just wanted to see how many points it collects. So far it has exceeded my wildest expectations, although that is mainly due to the content, not the title.

> although that is mainly due to the content, not the title

I'd beg to differ.

Re: How Lisp is Going to Save the World

#125

Post by jeffdavis » Wed, Jan 09, 2013, 7:34 PM UTC

david927 wrote: post #20

gnosis wrote: post #19

Earlier quoted context omitted.

Lisp is a multi-paradigm language that's perfectly capable of representing state. Perhaps you're confusing it with some purely functional language like Haskell.

I'm not saying it can't represent state; I'm saying that it promotes avoidance of state as a virtue.

Avoidance of state in general is a pretty ridiculous claim to make. Even when writing pure functions, the state consists of all of the arguments to all of the functions up the stack.

Re: How Lisp is Going to Save the World

#126

Post by egonk » Wed, Jan 09, 2013, 7:34 PM UTC

chimeracoder wrote: post #100

nemetroid wrote: post #86

I had Haskell as the subject in my intro course at university (my first experience with functional programming). I've tinkered a bit with it since then as well, and I'm at the "somewhat intuitive grasp of monad transformers" state. I tried Clojure some week ago through the Clojure koans that were posted here. Compared to Haskell I found the syntax very obtuse and it was not obvious why Lisp would be more powerful tha…

> I found the syntax very obtuse and it was not obvious why Lisp would be more powerful than Haskell. The easiest answer to that is, there's no syntax, which makes reimplementing your own Lisp parser trivial (one single function call, in fact). This in turn makes reimplementing your own Lisp, inline in Lisp, similarly trivial. That sounds like something out of an SICP exercise - and it is - but the same properties ma…

Have you got a good example where Lisp macros would work but standard Haskell would "fail"?

I've done some compiler work in Haskell like writing programs (semantic actions) as algebraic data structures and then transforming or interpreting the tree. Would I gain something by using Lisp macros in this instance?

Re: How Lisp is Going to Save the World

#127

Post by mark_l_watson » Wed, Jan 09, 2013, 7:41 PM UTC

cgag wrote: post #60

santu11 wrote: post #5

I am a intermediate programmer with just over one year experience. Everywhere I read about the power of lisp and really want to use it. If it is so good why ain't it is used more? It is very easy to get sites running using ASP .NET, wordpress, RoR or Django. I have worked on production sites using the first two. And personally tried on small projects on the last two. Is there a way to use Lisp professionally?

Clojure is very capable for web development, but getting started is not as clear cut as it is with something like Rails or Django. This is because the Clojure community tends to eschew large frameworks, and instead prefers using smaller, more focused libraries. This provides a lot of flexibility, but is intimidating at first because it requires you to choose your own libraries for routing, db interaction, templating,…

I do a lot of web development in Clojure using Noir, Compojure, Hiccup, etc.

I find this setup similar to using Ruby + Sinatra.

I still keep up to speed with Rails versions, etc., but in the last year almost all of my web development has been with either Clojure or Ruby + Sinatra.

Re: How Lisp is Going to Save the World

#128

Post by jeffdavis » Wed, Jan 09, 2013, 7:46 PM UTC

nemetroid wrote: post #86

I had Haskell as the subject in my intro course at university (my first experience with functional programming). I've tinkered a bit with it since then as well, and I'm at the "somewhat intuitive grasp of monad transformers" state. I tried Clojure some week ago through the Clojure koans that were posted here. Compared to Haskell I found the syntax very obtuse and it was not obvious why Lisp would be more powerful tha…

"Compared to Haskell I found the syntax very obtuse and it was not obvious why Lisp would be more powerful than Haskell."

Language "power" is ill-defined, and basically means "good".

If you think that homoiconicity is good, then you probably like lisp. If you think that referential transparency is good, then you probably like haskell. Those are mutually exclusive, so one language can't really have both. But either one could be considered "powerful" and either one could be said to help prevent bugs.

Re: How Lisp is Going to Save the World

#129

Post by jeffdavis » Wed, Jan 09, 2013, 7:48 PM UTC

king_magic wrote: post #83

S4M wrote: post #77

I fail to see how this is going to convince anybody who hasn't tried lisp to give it a shot. This cartoon can be summarised as "All languages are accumulating bugs while lisp has some magic X and Y that provide a way around them." A blub user will think "yeah whatever", IMHO.

My thoughts exactly, but I'd add this: I love and respect Lisp; I've written my fair share of it. There is absolutely nothing inherently magical in Lisp that prevent you from introducing bugs. You can just as easily make a logic error in your code that results in a bug. Bugs happen. Bugs will happen. There is no silver bullet. The only way to reduce bugs is to test thoroughly. tl;dr: nice cartoon, "lisp means no bugs…

"The only way to reduce bugs is to test thoroughly."

That is false.

Re: How Lisp is Going to Save the World

#130

Post by jgeralnik » Wed, Jan 09, 2013, 7:52 PM UTC

lispm wrote: post #113

mturmon wrote: post #110

Earlier quoted context omitted.

Software does not move tanks. It's one part of an overall system that moves tanks. You over-reached on that point; it happens.

Software moves fleets. Coordinates ten of thousands flights. Make sure that hundred thousands soldiers have supplies. It's called logistics. It's a new world. It happened. It's been said that this single piece of software paid back for all DoD AI research.

Just because supposedly a piece of software performing a critical purpose was written in lisp does not mean lisp won the war.

If the software wasn't written in lisp, it would have been written in any other language.

And if the software wasn't written at all there would have been hundreds of people doing the software's work manually instead.

Did the software help? Probably. It's likely there would have been more screw ups if there was no software. But it takes a big leap to credit the software with winning the war.