Show HN: I'm writing a leanpub book about Common Lisp web programming

http://lispwebtales.ppenev.com/

by pavelludiq • 13 years ago

107 33 13 years ago

lispwebtales.ppenev.com

pavelludiq8• 13 years ago

Link to leanpub page: https://leanpub.com/lispwebtales

pavelpanev22• 13 years ago

Why not use Thinatra?

parennoob3• 13 years ago

Wow, definitely something I am going to check out. From a quick look, it seems that your Lisp code for the example looks a lot like HTML itself. For example:

  (defun blogpage (&optional (posts *posts*))
       (html-frame
        "Restas Blogdemo"
         (<:div 
       	     (<:a :href (genurl 'add) "Add a blog post")
  	     (<:hr)
  	     (render-posts posts))))

I don't know much about functional programming though, so sorry if that's an incorrect assumption.

pavelludiq8• 13 years ago

Functions starting with <: are generated by the sexml library for outputting xml and html from lisp expressions. There are many similar libraries in pretty much every lisp dialect.

aerique• 13 years ago

See cl-who for another example: http://weitz.de/cl-who/#syntax

Also, this has nothing to do with functional programming but rather with creating a DSL (http://en.wikipedia.org/wiki/Domain-specific_language)

More links:

• http://www.tfeb.org/lisp/hax.html#HTOUT

• https://github.com/franzinc/aserve/blob/master/htmlgen/test....

parennoob3• 13 years ago

Ah, thanks. That was very helpful, specially the second link.

gcr4• 13 years ago

Most of the Lisp web frameworks look like that, taking advantage of Lisp's flexible syntax.

Here's a Racket example. If you download http://racket-lang.org, you can just run this (no extra libraries or anything) and a browser window will pop up for you.

    #lang web-server/insta
    
    ;; A "hello world" web server
    (define (start request)
      (response/xexpr
        '(html
           (body (h1 "Hello, world!")
                 (a ([href "http://google.com"]) "Google")
                 (br)
                 "I hope you like my site!"))))

This example renders as: <html><body><h1>Hello, world!</h1><a href="http://google.com>Google</a><br />I hope you like my site!</body></html>

pavelpanev22• 13 years ago

http://github.com/ober/thinatra

(get "/hello/:person1/:person2" "Hello #{person1} and #{person2}")

http://localhost:8021/hello/Jack/Jill "Hello Jack and Jill"

Much nicer imho than many of the ugly lisp ways. And all in Emacs Lisp.

DigitalJack• 13 years ago

Be sure to take a look at hiccup for clojure. https://github.com/weavejester/hiccup

parennoob3• 13 years ago

Nice, so if I understand correctly, this defines a function to return a simple html response any time a request is started.

shn• 13 years ago

I need help understanding one thing. This code generates HTML code. Fine. But how come code and declaration (web designer and developer) are separated with this. Is this a good practice? I've been reading about lisp for a long time, not in depth, but I keep stumbling similar snippets a lot. Are there any good examples out there? I am teaching myself Clojure (reading the book with the bird cover) these days.

nnq2• 13 years ago

What would the case for CL+Hunchentoot+... vs. Clojure+Noir+... sound like?

pavelludiq8• 13 years ago

In general if you prefer FP, clojure is a great choice. If you like multi-paradigm, and mixing up OO with FP, and procedural as you see fit, go with CL. I'm a multi-paradigm kind of guy, but clojure remains my second favorite language :)

ScottBurson• 13 years ago

Great! When you're done with this, can you be persuaded to write one about Weblocks?

I'm kidding, but not entirely. Weblocks is an extremely powerful and sophisticated framework, but it has a bit of a learning curve. It desperately needs a good tutorial.

serichsen• 13 years ago

You can actually get quite far just with Hunchentoot (and even its built-in "easy handlers"), CL-WHO and some Parenscript.

pavelludiq8• 13 years ago

Many lispers prefer to roll their own thin layers on top of hunchentoot, or even use it raw, but I prefer the slightly ticker layer of restas.

tbirdz• 13 years ago

An incredible coincidence -- I was starting to look into common lisp web programming just this morning, for a personal project. Do you have any estimate on when the book will be finished?

z3phyr• 13 years ago

Clojure buster? Great!

Su-Shee• 13 years ago

You should add a section about how a beginner is supposed to install all the components you're using.

Right now, you're treating it like they're all "just there".

pavelludiq8• 13 years ago

It's in the appendix A: http://lispwebtales.ppenev.com/chap06.html#appendix-a-gettin...

pnathan• 13 years ago

I also want to put in a plug for my site: http://articulate-lisp.com/

nnq2• 13 years ago

Is there any Django/Jinja-like templating engine for CL or Clojure?

...this way or the Clojure Hiccup way is cool for an ubergeek doing full-stack development, but in the real world you'll want your HTML templates separate and in a designer or front-end-coder friendly format. Otherwise, you may have the full power of Lisp at your fingertips, but you'll need to have your entire team used to this workflow and knowledgeable of Lisp, and by having logic in templates and such you're dangerously close to leaning towards the "PHP way".

...the only realistic "homogenous" solution for one language on the server and the client are the Javascript based way, in the Node ecosystem. Good designers or good front-end guys in general will also have coding skills, some will be Javascript gurus, but by doing things this way and writing Javascript code in Parenscript/Clojure script you'll have to force them to learn Lisp in order to work at 100%. And my bet is that they're not gonna like it, so team-wise, you'll lose all the productivity increase you gain in the first place by using Lisp.

IF you can find a team of lispers that also have webdesign and frontend coding skills, great, but this will be fucking hard as far as I know it. I would just love working in such an environment, but it seems like a non-existent Nirvana right now...

pavelludiq8• 13 years ago

There is a port of Googles closure-template system. It compiles closure templates to CL functions. They work pretty well. I have written about them in the book: http://lispwebtales.ppenev.com/chap04.html#closure-template

It also compiles to js, so you can even share templates between the client and the backend.

I'm experimenting with using both sexml and closure-template, but in the book I use almost exclusively sexml to make the code simpler. Also s-expressions are much easier to type in than sgml :)

juliangamble• 13 years ago

> but in the real world you'll want your HTML templates separate and in a designer or front-end-coder friendly format.

For Clojure - it sounds like you're looking for Christophe Grand's work on enlive: https://github.com/cgrand/enlive

You can read a tutorial here: https://github.com/swannodette/enlive-tutorial/

pavelludiq8• 13 years ago

There is also a recent Common Lisp enlive like library called Caramel: https://github.com/pocket7878/Caramel

muraiki3• 13 years ago

Note that you'll need to change (def base-url "http://news.ycombinator.com/) to (def base-url "https://news.ycombinator.com/) in the first example in order for it to work properly.

Show HN: I'm writing a leanpub book about Common Lisp web programming

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