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Closed 10 years ago.
Is LISP or something like Jess the best choice? I'm interested in writing a program that makes a suggestion based on users' answers. Computational considerations are not really a factor this is pretty much a pattern matching engine. Also I would like to make an app for this and put it up on the web.
UPDATE: I would like to put this up on a blog or website and let people use it from there. I guess my question then is there a particular inference engine that works with the .NET family, or PHP, or something to that effect? What are some of the pros and cons of each options etc.
Step 1. Pick an inference engine. There are many choices. Here's a list: http://en.wikipedia.org/wiki/Expert_system#Shells_or_Inference_Engine
Step 2. Use the language that interfaces with the inference engine.
You'll be much happier leveraging an inference engine for expert systems work.
I would like to put this up on a blog or website and let people use it from there
Trivial.
is there a particular inference engine that works with the .NET family, or PHP, or something to that effect?
Doesn't matter.
Here's the confusion. Your "web site" and your "inference application" have NOTHING to do with each other. Nothing.
Your web site can be done in any tool set you can find. It doesn't matter.
Your inference application can be done in any tool set you can find. It doesn't matter.
Your web site will invoke the inference application through any API that makes sense. The lowest common denominator in API's (the reason that none of these choices matter) is to do this.
Write your inference application as a stand-alone command line tool.
Write your web application to run the stand-alone tool, collect the output and turn the output into an HTML page.
Note that this multi-porocess implementation may be faster and make better use of multi-core processors. It forces the OS to manage the web server (Apache HTTPD, for example), the web application and the expert system as potentially three, separate, parallel processes.
You can also take a look at Prolog. SWI-Prolog (http://www.swi-prolog.org) is very complete and has an HTTP support library included (http://www.swi-prolog.org/pldoc/package/http.html). This paper might be helpful in using SWI-Prolog on the web ("SWI-Prolog and the web" http://dare.uva.nl/record/285350)
And, you can find a tutorial on building expert systems with prolog at: http://www.amzi.com/ExpertSystemsInProlog/
You will hear a lot of subjective opinions here, since few people have experience in more than one language writing expert systems.
I can recommend Common Lisp, as there is quite some literature and existing code available in this language, and it is a very powerful language and not too difficult to learn (read "Practical Common Lisp" by Peter Seibel). Of course, any new high level language requires some effort to learn. For the web application, you can use, e.g., Hunchentoot and CL-WHO, and there are a lot of database bindings (I like Postmodern and CL-SQLite).
I would suggest CLIPS and its .net port clipsnet
http://sourceforge.net/projects/clipsnet/
Related
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Closed 11 years ago.
I want to start working on a project where I want to build a intranet website and mobile app for people working in my office for car pooling. The basic idea is that if anyone is interested in looking for someone to carpool with should make a posting of going from A to B at time X.People can then reply to it.
I've narrowed down my option to Scala+Lift+MongoDB or Node.JS+Redis/MongoDB+HTML5. I don't know which one is better or worse for the problem I have mentioned. Also looking at developing mobile apps for the same application where people can send carpool request over their phones.Looking for a stack which can complement the mobile development also.
I know there are various solutions for this, but I'm looking to learn something new and exciting and have fun while developing it.
The only requirement that influences the technology stack is "looking to learn something new and exciting and have fun while developing it" (just as broofa said).
However I have no idea how he came from that requirement to JavaScript.
Yes it is more marketable
Yes there are way more people that know it.
Yes you'll need it any way.
But is JavaScript in anyway interesting as a language? Not much I'd say. Any nice unique (or at least rare) concepts? To me it looks like programming in java, but not being allowed to use anything but Hashmaps + java.lang.*
Scala on the other hand combines functional and object oriented in an extremely interesting way. It has a strong type system which enables tricks that probably will make your head spin.
And even if you don't use the really fancy stuff you have a super powerful language to work with.
So if you want to learn: Go with Scala
The capabilities of the technology stack here are probably unimportant. Both Scala and Node will allow you to implement a web interface / HTML5-based application for mobile devices.
So it boils down to your other requirement, "learn something new and exciting". If you're not familiar with node or JavaScript, I'd suggest Node because ...
JS is a much more marketable skill than Scala (currently)
If you want other people to work on this code, more people know JS than Scala.
You are only learning one new language instead of two. (You have to learn JS in either case to implement the front end. With Node, that expertise carries over to the server as well.)
... and even if you are familiar with JS, working with Node will make you a much better JS developer.
My $.02. You should get somebody who knows something about Scala to chime in here however.
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Closed 11 years ago.
What do you think about both?
I began reading a book about Catalyst, and found it pretty complex as compared to Dancer.
so now I'm giving Dancer a try, and it looks easier to learn and more "human friendly".
I think David's comment is very accurate and excellent. However, as someone who has done development in both but is not a developer on either perhaps I can be slightly more objective (and technical) in what the differences are.
Both frameworks provide a variation on the Web MVC paradigm.
Catalyst's main level of abstraction is the Controller. Catalyst expects you to break separate logic out into separate packages in some logical fashion (Login code goes here, Registration code goes there, Search functionality over here). This works incredibly well if you have a team of programmers since each of you can work on separate files and not step all over each other during merges. Catalyst provides a lot of tools for making the Controller logic extensible and flexible, I think the premier example of this is Chained actions which let you split up and build a complex flow for any given request. The downside is that it becomes very seductive to put your business logic into the Controllers and you end up with very fat logic in the Controllers where it (theoretically) belongs in the Model.
Dancer's main level of abstraction is the Route. My experience with Dancer is this leads to much smaller applications. Partly my experience here is tinged with the fact that I have dealt with several thousand line applications in Catalyst but I have yet to write a Dancer app that is longer than 200 lines (with a much smaller scope). I think however that this experience holds true. The push in Dancer is in keeping the Controller logic very thin because it doesn't have the same tools for managing complex behaviors there that Catalyst does.
Honestly I've enjoyed working in both of them. They both provide different opinions on what writing a web application is supposed to be. I would, given the time and inclination, recommend learning both ultimately.
This is a somewhat subjective question, but I'll try to give you an answer in an objective way. First things first, a disclaimer: I'm part of the Dancer development team, so my opinion should of course be considered somewhat biased :)
Catalyst is more widely used than Dancer, and so there's more community support behind it - if you were to look for contractors with experience working with either framework, say, you'd be more likely to find developers who've used Catalyst. So, if you're looking for commercial support, that would be a good reason to choose Catalyst.
Dancer is a younger project, and targeted more towards smaller projects, making getting up and running quick and easy, and trying to stay out of your way. That's not to say that Dancer isn't suitable for larger projects, however; the same habit of staying out of your way means you can organise your project in the way that suits you.
However, it has picked up a lot of support, and there's a growing community of helpful users and developers on IRC and the mailing list, and more and more useful plugins being released all the time. As with Catalyst, Dancer is designed so that you can pick and choose your preferred template engine, session storage backend etc, and it's easy to extend the framework by writing your own plugins if you need to.
For user testimonials to see what people say about Dancer, see the section at the bottom of the homepage on the new website: http://www.perldancer.org/
In the interests of showing other options, there's also Mojolicious, another modern Perl web framework which has been gaining in popularity lately.
Catalyst provides the same abstraction that Dancer does, Dancer's strength or rather Catalyst's weakness or rather Dancer's weakness is in how Catalyst forces the developer to adhere to Perl OO best practices and the MVC design pattern. After doing webapps for a while, this will all become apparent.
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Closed 12 years ago.
I know that Powershell is generally considered the IT management language for windows, but why/when would you choose F# instead, which is strongly typed and 'intellisensed' ?
I'd choose F# when it was a better fit for the company I was working for, the team who'll be using it, and the task at hand. Otherwise I'd choose something else.
I can't be more specific than that without more details, but I can suggest a few questions you should ask:
What is the problem you're solving?
In which language is it easier to express the solution to the problem?
Are existing staff F# developers themselves (i.e. consider the learning curve involved)?
Will the people maintaining this code be administrators (who are usually quite familiar with Powershell, & not at all familiar with F#)?
A related hint: don't allow a profusion of languages to develop in your production code and infrastructure.
By all means experiment to find the best language to solve the problem you're having, but if you find in five years time that someone has written a core component of your solution in a language that is no longer understood by anyone in the company, you may have a serious problem on your hands.
My personal rule of thumb (of course there are exceptions) is that a project should have a core language and a scripting language to hold it all together, & that those languages should be chosen first to fit the problem domain, and secondly to maximise proficiency across the team. 'Pet languages' should be strongly discouraged in production code or infrastructure.
It depends on your problem and on who will maintain the scripts.
PowerShell is very strong in administration areas (working with files, active directory, csv/xml, computers, etc.), but it's programming abilities are quite limited (e.g. case of generics). Threading in PowerShell is not as easy as it could be. But nobody expects from administrators that they will use threads. Instead there are background jobs that satifisfy administrator's needs.
On the other hand, F# is real programming language, which means it is quite low level and therefore verbose (compared to PowerShell). Some tasks written in PowerShell are one-liners, whereas in F# you would write a lot of code. Besides that - how would you achieve running command on remote computers (Invoke-Command -computer myserver ...)?
As you see, it depends on your problem.
Very important is also who will maintain the scripts. You might be on holiday and your colleagues will need to edit the scripts. Both languages need some time to learn. IMHO it is easier to learn PowerShell; thinking in functional style needs to bend your head.
It is probably a bad idea, at this point in time, to choose to write scripts in F# if they might be needed by anyone other than yourself ...
The cadre of F# speaking people is very small, so you're creating scripts which very few people can read or edit.
The fsi executable doesn't come with the .Net Framework, nor is it part of the F# runtime redistribution package (as far as I can tell). This means the scripts can only be executed where Visual Studio with F# tools have been installed.
The obvious exception, of course, is if you're a developer working on a project where F# is a primary language, since that will mean that everyone that matters will be able to run and edit your scripts.
However, I have to say that I think even in this ideal/exceptional case, it would probably be more work to use F# if your scripting task involves tasks for which there are pre-existing cmdlets in PowerShell (ie: filesystem tasks, registry, database maintenance, active directory, exchange, the list goes on and on). Of course, you might still choose to do it if you're using these scripts as an opportunity to learn the language, but bear in mind points 1 & 2 ;-)
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Closed 10 years ago.
As an artist and musician, I often want to sit down and just let the code roll like a piece of free-form poetry, but I've found that doesn't work as well as when I have a set goal in mind. I've been experimenting lately with setting up tiny, fun goals for myself, not unlike how an artist would sketch a quick still-life, but I wonder...
What do others do when they want to code for fun, without the bondage of an already-committed project?
Design work, I find, flows much easier than just coding. I find that coding is often more of just implementation of a good design; I really like to just sit down with a pad of paper and a pen (and likely a bottle of wine) and work out an interesting design.
Project Euler is where I'm having fun at now. I can go at my own pace and work on the problems that interest me. Also, work in any language I choose.
Write documentation when coding doesn't come easy - coding will quickly seem much more appealing!
Going for a walk outside.
I tend to map my idea or build a structure in a MindMapping tool like MindMeister. And it's great for a team because it can be edited in real time by multiple persons!
I like to pick up a new language and learn how to express ideas in it. This usually has the benefit of showing me what I like and don't like about the languages I currently use. I usually pick some little tool project I've been wanting to do. Using the new language angle get's me motivated
My most recent 'new language' is Scala, in this case it will likely become a langue I use.
I like writing on whiteboards. Great for db diagrams, task lists, feature lists, (other lists,) random ideas, notes, etc. (db diagrams being the biggie for me)
Python is great for just getting things going on an idea and having the language (usually) behave like you would expect.
While it may have its drawbacks, it sounds like a great fit for what you are describing.
So to answer your question, the Python Challenge is entertaining and often gets me thinking about little things that would be fun to code, probably because it exposes you to different types of problems.
I like to code.
I like to find something interesting, code it and then see it works.
It does not have to be a project per see, it's good enough if it does something, like use Google api to get picasa albums, change song in iTunes or get details of current iTunes song, automate downloading of document from web site that is behind login and requires cookies and all that stuff, data parser in python, simple app on Mac, core data application, google codejam problems, topcoder.com problems ...
I like to learn new features of some language or some new language/technology/patterns/tool :-)
Usually I will work in Photoshop for a while. Get creative and try to come up with a new design that's not constrained by any code. Maybe even find something inspiring on the web for some new design ideas... then try to implement the design in code. That's the fun and challenging bit.
Use the REPL.
You figure out broadly the sort of thing you need to do - what APIs you need to use, what data structures you need to handle - and then prod them interactively until they start making sense. A ton of languages I use now have REPLs: Ruby, Python, Scala, Java (BeanShell, or JRuby/Jython etc.), C# ('csharp'), PHP (Facebook have made a REPL for it), Smalltalk (GNU gst) and, obviously, LISP/Scheme.
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Closed 10 years ago.
Never been a lisp user, so don't take me as too dense while reading this. However;
What is lisp used for today?
I know there are several variants of the language in existence, at least one which will keep it alive commercially for a while longer (AutoLisp, VisualLisp - pretty big support from Autodesk)... But I don't meet everyday people using it. So if you could shed some light on the matter:
What is its primary target market nowadays?
And what do you believe its future will be?.. Will it become just another support language in few apps, or is it going somewhere?
Also, apart from "an editor whose name shall not be spoken";
What other apps keep it as a support language ?
The Lisp dialect Clojure seems to be growing in popularity - you might ask out at http://clojure.org/ in one of the forums to see what real-world apps people are building with it.
One example from my lisp projects:
ShareBot: It downloads stock market data, analyses it and trades automatically. Credits money into my bank account every month!
Aircraft Design : http://www.piano.aero/
LispWorks lists several applications : http://www.lispworks.com/success-stories/index.html
Franz technologies are widely applicable : http://www.franz.com/
I wanted to typeset some music last week, and the program with the best reputation (free or otherwise) seemed to be Lilypond. I was pleasantly surprised to see it's largely written in, and customizable with, Scheme.
Mostly for configuring and extending Emacs!
*ducks*
CoCreate Modeling, now CREO Elements/Direct Modeling, an extensive 3D CAD application uses Common Lisp as its extension language. AFAIK there are now 7M+ LOC in Common Lisp for that application. Actually Common Lisp is not only the extension language, but large parts of the application are written in Common Lisp (plus some C++).
Other than that Lisp is a family of diverse dialects with diverse implementations (Scheme, Common Lisp, Emacs Lisp, Visual Lisp, Clojure, Logo, ...) and several others.
Strengths are for example:
symbolic computing (Maxima, Reduce, Axiom, ACL2, ...)
AI, Semantic Web, ... (see the customer stories of Franz for some examples)
CAD (AutoCAD, CoCreate, and several others)
Music (OpenMusic, Common Music, PWGL, ...)
graphical applications (see the LispWorks customer stories for some examples)
development environments (Emacs and others)
Education (DrScheme, ...)
Also see the topics of the International Lisp conference 2009. This should give you an impression what people are using Lisp for and what new ideas they are thinking about.
Seems to be existent in the job market
24 jobs on dice.
Common Lisp isn't widely used in the field at all, but here is one of the most succesful applications I know of.
ITA Software: Airfare Shopping Engine and Franz lisp has a list of others.
Today lisp is used AI System where the sympolic Data explanation is used.Mainly Lisp is devloped by show the functioning of List. but it use as a symbolic representative language
It is used for anything ant everything that all other programming languages are used for, including web, games, internal applications, ...