In article <sfwu1w1qj0g....@shell01.TheWorld.com>, Kent M Pitman wrote: > Isn't that what Bruce is suggesting? Lazy as in returning a "future" (a > promise for a result that's still being computed, as in the Star Trek > Classic episode "A Wolf In the Fold").
I don't recall that episode by name, but yes, a lazy result as in "pipes" in PAIP and "streams" in SICP. I can see how lazy continued-fractions can be used for arbitrary precision arithmetic. So, if one wrote their own (exp) and (return-pi) functions using continued fractions [cf], one could get a T result for (zerop (1+ (my-cf-exp (complex 0 (my-cf-pi-generator))))) "after" calculating infinitely .
Kevin Rosenberg <ke...@rosenberg.net> writes: > In article <sfwu1w1qj0g....@shell01.TheWorld.com>, Kent M Pitman wrote: > > Isn't that what Bruce is suggesting? Lazy as in returning a "future" (a > > promise for a result that's still being computed, as in the Star Trek > > Classic episode "A Wolf In the Fold").
> I don't recall that episode by name,
The immortal spirit of Jack the Ripper gets into the computer, and Spock tells the computer to "compute to the last digit, the value of pi"... He made it a class 1 priority directive to assure that the the computer would turn bank after bank to the problem, squeezing out the bad guy, who is presumably not smart enough to hide in the area that has life support and will (hopefully) be last to go.
> but yes, a lazy result as in > "pipes" in PAIP and "streams" in SICP. I can see how lazy > continued-fractions can be used for arbitrary precision arithmetic. So, > if one wrote their own (exp) and (return-pi) functions using continued > fractions [cf], one could get a T result for > (zerop (1+ (my-cf-exp (complex 0 (my-cf-pi-generator))))) > "after" calculating infinitely .
>> Finally, maybe somebody would give me at least one good reason (other than >"because I like >> it") why LISP should be used instead of one of the above mentioned languages.
>troll.
I am not a troll. I am in charge of selecting tools for AI-based components of products being developed by my company (it does't matter what is the name). Our business area is supply channel management and logistics. These AI based components are mostly constraint programming and agents. We are currently using Prolog, but Prolog (despite its obvious advantages) has obvious disadvantages. One is that it is pretty hard (well... inconvenient) to write parts of the algorithm that have purely procedural character. Since we are extending the product lines, one obvious question is whether it would be reasonable and justified to use something else instead of Prolog. LISP definitely is the alternative, but... I have posted a qeustion about constraint solver for LISP - it seems that nothing is available. There are several for Prolog, Java anc C++. I have also posted question about interfaces to commercial linear programming solvers. None. There are number of them for Prolog, C++ and Java.
Therefore, again: could you give me a reason why we should use LISP?...
* Andrzej Lewandowski <lewandoREM...@attglobal.net> | Technical decision in the industry are not based on "trust" or personal | opinions of this-or-that developer. Developers don't decide about | programming languages unless this is single person, basement-type | operation.
I can only pity you for your lack of experience, but these things happen quite frequently. It probably does not apply in the Java, C++, VB, etc, world, where trust in the developer is a non-issue, where the personal value of the individual programmer seems to be irrelevant at best, and where the ability to replace such a programmer is valued much higher than making sure that programmer contributes to the company's bottom line. However, this extremely sorry situation is _not_ representative of the whole world, despite the fact that those who live under such conditions would leave the second they learned freedom was available to them, too, and thus nobody in that world will believe it is possible to be trusted, to have their opinions heard, to be both designer and programmer, etc.
Of course, I am only slightly exaggerating, but those who think their personal experiences up to some point make it unnecessary to ever open their eyes again and thus declare everything contrary to their personal experience invalid at best or a lie at worst, have already given up the most important value of being conscious: The world you experience is not what you expect it to be, if you look closely enough, and that looking at it with open eyes all the time is the only working way to deal with it.
/// -- Norway is now run by a priest from the fundamentalist Christian People's Party, the fifth largest party representing one eighth of the electorate. -- Carrying a Swiss Army pocket knife in Oslo, Norway, is a criminal offense.
Andrzej Lewandowski <lewandoREM...@attglobal.net> writes: > but... I have posted a qeustion about constraint solver for LISP - > it seems that nothing is available. There are several for Prolog, > Java anc C++. I have also posted question about interfaces to > commercial linear programming solvers. None. There are number of > them for Prolog, C++ and Java.
Have you looked at LispWorks from Xanalys (www.xanalys.com)? Their "Enterprise Edition" comes with an embedded prolog interpreter that can use either a Lisp'ish or traditional prolog syntax. Might give you the best of both worlds.
On Sun, 11 Nov 2001 20:43:31 GMT, Gabe Garza <g_ga...@ix.netcom.com> wrote: >Andrzej Lewandowski <lewandoREM...@attglobal.net> writes:
>> but... I have posted a qeustion about constraint solver for LISP - >> it seems that nothing is available. There are several for Prolog, >> Java anc C++. I have also posted question about interfaces to >> commercial linear programming solvers. None. There are number of >> them for Prolog, C++ and Java.
> Have you looked at LispWorks from Xanalys (www.xanalys.com)? Their >"Enterprise Edition" comes with an embedded prolog interpreter that can >use either a Lisp'ish or traditional prolog syntax. Might give you the >best of both worlds.
This is not what I am looking for. I would like to replace Prolog by LISP, but not bring one more language to the organization. Moreover, I am not using just-a-Prolog. I am using Prolog that has built-in constraint solver (CLP(fd), strictly speaking), and currently there are 5 such Prologs on the market. This what Xanalys has doesn't belong to this category.
On Sun, 11 Nov 2001 20:40:29 GMT, Erik Naggum <e...@naggum.net> wrote: >* Andrzej Lewandowski <lewandoREM...@attglobal.net> >| Technical decision in the industry are not based on "trust" or personal >| opinions of this-or-that developer. Developers don't decide about >| programming languages unless this is single person, basement-type >| operation.
> I can only pity you for your lack of experience, but these things happen > quite frequently.
Andrzej Lewandowski <lewandoREM...@attglobal.net> writes: > We are currently using Prolog, but Prolog (despite its obvious > advantages) has obvious disadvantages. One is that it is pretty hard > (well... inconvenient) to write parts of the algorithm that have > purely procedural character. Since we are extending the product > lines, one obvious question is whether it would be reasonable and > justified to use something else instead of Prolog. LISP definitely > is the alternative, but... I have posted a qeustion about constraint > solver for LISP - it seems that nothing is available.
Harlequin (now Xanalys) used to have an integrated Lisp/Prolog environment, I think. I don't know if it still does. And I think it has their KnowledgeWorks expert system shell, which is either the same thing or something similar -- I know it's something that integrates with Lisp at the meta-object level. I don't know the details, nor do I get a commission for mentioning it, but I'd recommend contacting them.
I'm sure there are expert system shells and constraint solvers written in Lisp. How to go about looking for them seems more the problem. That's an important issue, for sure, but it arguably isn't one that you should take up on a disorganized newsgroup. I might suggest take it up with individual Lisp vendors sales/marketing departments. I'd be surprised if Franz couldn't help you, too.
Of course, you didn't say you were willing to pay money for a solution, but I'm assuming if it has commercial value to you that you are.
> Therefore, again: could you give me a reason why we should use LISP?...
I posted a response to this under separate cover so won't repeat myself.
>> We are currently using Prolog, but Prolog (despite its obvious >> advantages) has obvious disadvantages. One is that it is pretty hard >> (well... inconvenient) to write parts of the algorithm that have >> purely procedural character. Since we are extending the product >> lines, one obvious question is whether it would be reasonable and >> justified to use something else instead of Prolog. LISP definitely >> is the alternative, but... I have posted a qeustion about constraint >> solver for LISP - it seems that nothing is available.
>Harlequin (now Xanalys) used to have an integrated Lisp/Prolog >environment, I think. I don't know if it still does. And I think it >has their KnowledgeWorks expert system shell, which is either the same >thing or something similar -- I know it's something that integrates >with Lisp at the meta-object level. I don't know the details, nor do >I get a commission for mentioning it, but I'd recommend contacting them.
>I'm sure there are expert system shells and constraint solvers written in >Lisp.
Expert systems, yes. What regards constraint solvers, there is one named Screamer, but it is academic project abandoned in 1994 (and it seems, never finished). I am looking for commercially supported stuff.
>How to go about looking for them seems more the problem. That's >an important issue, for sure, but it arguably isn't one that you should >take up on a disorganized newsgroup. I might suggest take it up with >individual Lisp vendors sales/marketing departments.
Response mostly negative.
>Of course, you didn't say you were willing to pay money for a solution, >but I'm assuming if it has commercial value to you that you are.
Exactly. I am looking for commercial solution, with support etc. But I am not going to pay substantially more than for Prolog, C++ or Java solutions...
it seemed that way since you did not offer all this other useful background in your original somewhat contentious "one good reason" challnege--didn't really seem like a question, and indeed it still seems as if you have made up your mind and are just looking for a scrap. But maybe that is just your style, so...
> I have posted a qeustion about constraint solver for LISP - it seems > that nothing is available. There are several for Prolog, Java anc C++. I have also posted question > about interfaces to commercial linear programming solvers. None. There are number of them > for Prolog, C++ and Java.
Can you call these commercial packages thru the Lisp foreign function interface? Would that be acceptable? We use a few third party packages in our app, none of them in Lisp.
> Therefore, again: could you give me a reason why we should use LISP?...
I think first we need to figure out if you can get to the commercial constraint systems you like from Lisp, or it does not matter how many reasons there are for using Lisp. Is that right?
Andrzej Lewandowski <lewandoREM...@attglobal.net> writes: > On Sun, 11 Nov 2001 21:31:41 GMT, Kent M Pitman <pit...@world.std.com> wrote: > >How to go about looking for them seems more the problem. That's > >an important issue, for sure, but it arguably isn't one that you should > >take up on a disorganized newsgroup. I might suggest take it up with > >individual Lisp vendors sales/marketing departments.
> Response mostly negative.
Did you tell them your situation, why you were considering Lisp, what problem area you were going to be tackling, why you needed the features you do, and did you sound receptive to help; or, did you post a demand without any context, like you did on c.l.l?
If you spoke to the vendors like you initially did to this newsgroup, I can understand the negative response. You didn't sound serious nor receptive. Context is good, if you want help, give it.
-- /|_ .-----------------------. ,' .\ / | No to Imperialist war | ,--' _,' | Wage class war! | / / `-----------------------' ( -. | | ) | (`-. '--.) `. )----'
>>> but... I have posted a qeustion about constraint solver for LISP - >>> it seems that nothing is available. There are several for Prolog, >>> Java anc C++. I have also posted question about interfaces to >>> commercial linear programming solvers. None. There are number of >>> them for Prolog, C++ and Java.
>> Have you looked at LispWorks from Xanalys (www.xanalys.com)? Their >>"Enterprise Edition" comes with an embedded prolog interpreter that can >>use either a Lisp'ish or traditional prolog syntax. Might give you the >>best of both worlds.
> This is not what I am looking for. I would like to replace Prolog by LISP, > but not bring one more language to the organization. Moreover, I am not > using just-a-Prolog. I am using Prolog that has built-in constraint solver > (CLP(fd), strictly speaking), and currently there are 5 such Prologs on > the market. This what Xanalys has doesn't belong to this category.
> >" > >I also think that trust *is* the major factor. This applies to in-house and > >even more to contract programming. > >The trouble for new programmers is that they don't have the years of > >practice that build that trust. They have to build it by solving problems in > >an efficient and clean way. (rather easy compared to the Java/C*/script > >languages/etc. crowds)
> Technical decision in the industry are not based on "trust" or personal opinions of > this-or-that developer.
You are either naive or lucky...
> Developers don't decide about programming languages
Yes Sir! If you are talking about corporate drones, then yes we agree, but these guys don't decide on anything.
>unless this > is single person, basement-type operation. These mechanisms cause that it is very hard to > convince management to use something that is not Java, C++ or VB.
> Finally, maybe somebody would give me at least one good reason (other than "because I like > it") why LISP should be used instead of one of the above mentioned
languages.
There are lots of reasons why Lisp is currently the best way to write software, but as you told us in other posts, you are not looking for this, you just need a constraint solver.
> >> Finally, maybe somebody would give me at least one good reason (other than > >"because I like > >> it") why LISP should be used instead of one of the above mentioned languages.
> >troll.
> I am not a troll. I am in charge of selecting tools for AI-based
components of products
Your tone looks like you are trolling
> being developed by my company (it does't matter what is the name).
Curious people can find it in a few seconds just by typing your name + CLP in google...
> Our business area is > supply channel management and logistics. These AI based components are mostly constraint > programming and agents. We are currently using Prolog, but Prolog (despite its obvious > advantages) has obvious disadvantages. One is that it is pretty hard (well... > inconvenient) to write parts of the algorithm that have purely procedural character. Since > we are extending the product lines, one obvious question is whether it would be reasonable > and justified to use something else instead of Prolog. LISP definitely is the alternative, > but... I have posted a qeustion about constraint solver for LISP - it seems that nothing > is available. There are several for Prolog, Java anc C++. I have also posted question > about interfaces to commercial linear programming solvers. None. There are number of them > for Prolog, C++ and Java.
> Therefore, again: could you give me a reason why we should use LISP?...
Your problem is that you put a constraint : "Must have a commercially supported constraint solver written in it" So in *your* case, as it doesn't seem there is one in Lisp we can all infer that you can't use Lisp. It's like if somebody wants to write an Excel macro, Lisp will probably not be the best solution to his needs.
Nobody said that Lisp was the solution for every problem in the world. Lisp is the best solution to write programs to solve problems, but *you* don't want to program, *you* want to use a constraint solver and nobody has ever said that Lisp was the best solution to use a constraint solver. So *you* have no reasons to use Lisp (at least in this case)
jeff <jn...@houseofdistraction.com> writes: > VisualBasic is to BASIC as Modula-2 is to Pascal. It's not really the > same language. But it does offer a good example of what CL needs to
Modula-2 is to Pascal as ANSI Common Lisp is to Lisp 1.5 ...
> the VisualCommonLisp project as soon as I figure out how to get CL to > talk efficiently & easily to GTK.
You might want to look at cl-gtk and clg. clg packages for CMUCL just went into cCLan, oddly enough
In article <5d9tut8kvj1dh20sneriuobe6dfrf0a...@4ax.com>, Andrzej
Lewandowski <lewandoREM...@attglobal.net> wrote: > Technical decision in the industry are not based on "trust" or > personal opinions of this-or-that developer. Developers don't > decide about programming languages unless this is single person, > basement-type operation. These mechanisms cause that it is very > hard to convince management to use something that is not Java, > C++ or VB.
I guess you're new.
When I started using C++ for production work in 1989 it was exactly as hard to convince management to use C++ then (instead of C or Pascal or FORTRAN) as it is to convince them to use CL or Dylan now.
C++ was established mostly from the grassroots level. Source-level compatibilty with C helped it, but I don't think it was essential.
Java and VB seem to have some in more from the other end -- large companies persuaded managament that they should use them, and they were then imposed on developers.
> Finally, maybe somebody would give me at least one good reason > (other than "because I like it") why LISP should be used instead > of one of the above mentioned languages.
Exactly the same reason that Java should often be used instead of C, but squared.
Personally, I prefer Dylan, but I'd be perfectly happy to see CL start to win, too.
In article <87668hjm71....@noetbook.telent.net>, Daniel Barlow wrote: >jeff <jn...@houseofdistraction.com> writes:
>> VisualBasic is to BASIC as Modula-2 is to Pascal. It's not really the >> same language. But it does offer a good example of what CL needs to
>Modula-2 is to Pascal as ANSI Common Lisp is to Lisp 1.5 ...
Modula 2 and Pascal are distinct languages, that lead parallel lives and are separately standardized; so it's not exactly true that Pascal is an obsolete version of Modula 2.
The Pascal standards are:
ISO 7185:1990 (Programming Languages --- Pascal) and ISO 10206:1990 (Programming Languages --- Extended Pascal).
Both can be found in PostScript form on the net; I don't know whether these are latest. Modula has these:
ISO 10514-1:1996 (Modula-2 --- Base Language) ISO 10514-2:1998 (Modula-2 --- OO extension) ISO 10514-3:1998 (Modula-2 --- Generic extension)
Daniel Barlow wrote: > jeff <jn...@houseofdistraction.com> writes: >>the VisualCommonLisp project as soon as I figure out how to get CL to >>talk efficiently & easily to GTK.
> You might want to look at cl-gtk and clg. clg packages for CMUCL just > went into cCLan, oddly enough
>> On Sun, 11 Nov 2001 21:31:41 GMT, Kent M Pitman <pit...@world.std.com> wrote:
>> >How to go about looking for them seems more the problem. That's >> >an important issue, for sure, but it arguably isn't one that you should >> >take up on a disorganized newsgroup. I might suggest take it up with >> >individual Lisp vendors sales/marketing departments.
>> Response mostly negative.
>Did you tell them your situation, why you were considering Lisp, what >problem area you were going to be tackling, why you needed the >features you do, and did you sound receptive to help; or, did you post >a demand without any context, like you did on c.l.l?
>If you spoke to the vendors like you initially did to this newsgroup, >I can understand the negative response. You didn't sound serious nor >receptive. Context is good, if you want help, give it.
I don't understand what the "tone" has to do here. Vendors are in money making business, and, whoever they are, they are looking for customers. I do know how to talk to vendors, you don't need to teach me. I posted "I am looking for CLP solver" message AFTER talking to vendors, searching google, alta vista and all possible ways, as well as e-mailing and calling people that are in constraint solving business. I don't know what "context" (and WHAT context) of my question has anythuing in common with constraint solving, LISP and my question.
>>>> but... I have posted a qeustion about constraint solver for LISP - >>>> it seems that nothing is available. There are several for Prolog, >>>> Java anc C++. I have also posted question about interfaces to >>>> commercial linear programming solvers. None. There are number of >>>> them for Prolog, C++ and Java.
>>> Have you looked at LispWorks from Xanalys (www.xanalys.com)? Their >>>"Enterprise Edition" comes with an embedded prolog interpreter that can >>>use either a Lisp'ish or traditional prolog syntax. Might give you the >>>best of both worlds.
>> This is not what I am looking for. I would like to replace Prolog by LISP, >> but not bring one more language to the organization. Moreover, I am not >> using just-a-Prolog. I am using Prolog that has built-in constraint solver >> (CLP(fd), strictly speaking), and currently there are 5 such Prologs on >> the market. This what Xanalys has doesn't belong to this category.
Yes, I know Mercury. Other option (even better) wpuld be Mozart-Oz www.mozart-oz.org Unfortunately, both don't offer maintenance/support, both are experimental, and there is no sufficient experience with applying this stuff in large commercial projects.
> >> On Sun, 11 Nov 2001 21:31:41 GMT, Kent M Pitman <pit...@world.std.com> wrote:
> >> >How to go about looking for them seems more the problem. That's > >> >an important issue, for sure, but it arguably isn't one that you should > >> >take up on a disorganized newsgroup. I might suggest take it up with > >> >individual Lisp vendors sales/marketing departments.
> >> Response mostly negative.
> >Did you tell them your situation, why you were considering Lisp, what > >problem area you were going to be tackling, why you needed the > >features you do, and did you sound receptive to help; or, did you post > >a demand without any context, like you did on c.l.l?
> >If you spoke to the vendors like you initially did to this newsgroup, > >I can understand the negative response. You didn't sound serious nor > >receptive. Context is good, if you want help, give it.
> I don't understand what the "tone" has to do here. Vendors are in > money making business, and, whoever they are, they are looking for > customers. I do know how to talk to vendors, you don't need to teach > me. I posted "I am looking for CLP solver" message AFTER talking to > vendors, searching google, alta vista and all possible ways, as well > as e-mailing and calling people that are in constraint solving > business. I don't know what "context" (and WHAT context) of my > question has anythuing in common with constraint solving, LISP and > my question.
Who said anything about "tone" (besides you)? I don't know how the commercial vendors budget their customer service time, but if you didn't give them enough information to know what you were trying to do, and if you didn't sound serious, I wouldn't be surprised if they didn't take you as seriously as they would have if you sounded like a serious request. You sure didn't sound serious at first, here.
-- /|_ .-----------------------. ,' .\ / | No to Imperialist war | ,--' _,' | Wage class war! | / / `-----------------------' ( -. | | ) | (`-. '--.) `. )----'
Andrzej Lewandowski <lewandoREM...@attglobal.net> writes:
| Expert systems, yes. What regards constraint solvers, there is | one named Screamer, but it is academic project abandoned in 1994
Perhaps you should tell that to the authors, too; they might not be aware that they have abandoned the project. The latest version (which I got from the other author (Siskind) about two months ago) I have mentions 1997 and I don't recall him mentioning that it is abandoned.
| (and it seems, never finished). I am looking for commercially | supported stuff.
I take it that asking whether the authors might be willing to sell you commercial support is out of the question? On second thought, if you ask them, I'd advice you not to tell your silly assumptions about their "abandoned project" to them as truths.
On Sun, 11 Nov 2001 22:12:11 GMT, Kenny Tilton <ktil...@nyc.rr.com> wrote:
>Andrzej Lewandowski wrote: >> I am not a troll.
>it seemed that way since you did not offer all this other useful >background in your original somewhat contentious "one good reason" >challnege--didn't really seem like a question, and indeed it still seems >as if you have made up your mind and are just looking for a scrap. But >maybe that is just your style, so...
>> I have posted a qeustion about constraint solver for LISP - it seems >> that nothing is available. There are several for Prolog, Java anc C++. I have also posted question >> about interfaces to commercial linear programming solvers. None. There are number of them >> for Prolog, C++ and Java.
>Can you call these commercial packages thru the Lisp foreign function >interface? Would that be acceptable? We use a few third party packages >in our app, none of them in Lisp.
Yes, but this would be technical and economical nonsense. I can call these modules from C++ already, and I can do in C++ what I can do in LISP (although I would prefer LISP). Adding additional layer would have no sense. Moreover, such layer would increase all possible costs - tools, implementation and runtime fees. Each time I want to introduce new tool, I have to provide arguments that this new tool will simplify development, reduce cost and reduce time to market. Bringing LISP as interafce between C++ and C++ could be not justified. Bringing Prolog as constraint solver simplified a lot of things, reducing essentially the development and reducing the cost
>> Therefore, again: could you give me a reason why we should use LISP?...
>I think first we need to figure out if you can get to the commercial >constraint systems you like from Lisp, or it does not matter how many >reasons there are for using Lisp. Is that right?
No. Question was rhetorical. In this sense I AM a troll :) I always consider amusing discussions between guys from the academia on "what to do to make language XXX more popular in the industry". By the way, this is not only LISP. See Eiffel, for example. In most cases they have the same knowledge of industry as I have about Japanese dance Kabuki. Don't be offended guys, I spent 25 years in the Academia. I know :)
Being serious: I want to know whether selecting Prolog was The Best Idea. Bringing Prolog as constraint solver simplified a lot of things, reduced essentially the development and runtime cost. As I have mentioned, from technical standpoint it is not the ideal one. Maybe there is better solution. Or Prolog is the best. Who knows. Therefore, the question: is there any other language that
1. Would replace Prolog and the associated functionality, 2. There is sufficient number of commercially available components or interfaces to these components (constraints, LP solvers, database, COM), 3. Would have better run-time efficiency than Prolog, 4. Would have adequate support and maintenance, 5. Vendors would be in good financial health, thus giving guarantee that they will not go belly-up next year. There should be more than a single vendor, 6. Using this language would be cost effective, with little impact on the bottom-line (i.e. no runtime fees or small runtime fees), 7. Is the language known for long enough and is there established record of commercial applications, 8. Is it easy to find EXPERIENCED programmers somewhere here, not, say in the Antarctica (training is not the option), 9. How much such programmers would cost.
LISP is obvious candidate, with many positive answers, but not all. At least, for today.
A.L.
P.S. By the way, first time I was using LISP about 1970, on CDC 6600 and CDC 3170 "supercomputers"... This was fun. On punched cards.
On Sun, 11 Nov 2001 23:47:50 +0100, "Marc Battyani" <Marc.Batty...@fractalconcept.com> wrote:
>> Finally, maybe somebody would give me at least one good reason (other than >"because I like >> it") why LISP should be used instead of one of the above mentioned >languages.
>There are lots of reasons why Lisp is currently the best way to write >software, but as you told us in other posts, you are not looking for this, >you just need a constraint solver.
I know that LISP is the best way of writing software, but for me, if it lacks constraint solver it is useless. It lacks some other things that I consider critical. And that C++, Java, VB, Prolog and others provide without troubles and with pleasure.
