[racket] error from web-server tutorial

From: Jay McCarthy (jay.mccarthy at gmail.com)
Date: Mon Dec 5 00:36:38 EST 2011

You are using Racket 5.1, but you are reading the documentation from 4.2.1.

If you read the documentation for the version you are using, by going to
the Help Desk link, or looking at this closely related on online:

http://docs.racket-lang.org/continue/index.html

You'll see that the example is different now:

#lang web-server/insta
(define (start request)
  (response/xexpr
   '(html
     (head (title "My Blog"))
     (body (h1 "Under construction")))))


Jay

On Sat, Dec 3, 2011 at 12:10 PM, lothar atheling <lothar_ at warpmail.net>wrote:

> re: http://download.plt-scheme.org/doc/4.2.1/html/continue/index.html
>
> hello,
>
> i am having trouble getting to run the 1st example in
> tutorial "Continue: Web Applications in PLT Scheme", here:
>
>  #lang web-server/insta
>  (define (start request)
>   '(html
>     (head (title "My Blog"))
>     (body (h1 "Under construction"))))
>
>
> what is returned is following web page at
>  http://localhost:2906/servlets/standalone.rkt
>
> Exception
> The application raised an exception with the message:
>
> self-contract violation: expected <can-be-response?>, given: '(html
> (head (title "My Blog")) (body (h1 "Under construction")))
>  contract on start from you, blaming you
>  contract:
>    (-> request? can-be-response?)
>
> Stack trace:
>
> raise-blame-error at:
>  line 58, column 0, in file H:\Program
>  Files\Racket\collects\racket\contract\private\blame.rkt
> <unknown procedure> at:
>  line 58, column 2, in file H:\Program
>  Files\Racket\collects\web-server\dispatchers\dispatch-servlets.rkt
> select-handler/no-breaks at:
>  line 164, column 2, in file H:\Program
>  Files\Racket\collects\racket\private\more-scheme.rkt
> connection-loop at:
>  line 74, column 2, in file H:\Program
>  Files\Racket\collects\web-server\private\dispatch-server-unit.rkt
>
>
> i am using racket 5.1
>
>
> --
> http://www.fastmail.fm - mmm... Fastmail...
>
> _________________________________________________
>  For list-related administrative tasks:
>  http://lists.racket-lang.org/listinfo/users
>



-- 
Jay McCarthy <jay at cs.byu.edu>
Assistant Professor / Brigham Young University
http://faculty.cs.byu.edu/~jay

"The glory of God is Intelligence" - D&C 93
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.racket-lang.org/users/archive/attachments/20111204/3e5216e2/attachment.html>

Posted on the users mailing list.