[Haskell-cafe] How to generate random string?

[mf-hcafe-15c311f0c at etc-network.de]

does this compile at all?  i don't think i understand the first line.
anyway, a few hints:

  - if you want to have all numbers between 0..n in your output for
    some n, just in random order, google for "permutation".

  - perhaps you can generate the output in an ordered fashion first,
    eg. into an array, and then shuffle the list by plucking elements
    from it at random into a new list.

  - do not use unsafePerformIO.  it may reduce the entropy
    (randomness) of the results, but even if it doesn't, the code is
    prettier without.

good luck!  if you get stuck again, just post more code.
matthias


On Fri, Sep 18, 2009 at 10:14:53AM -0700, Snouser wrote:
> To: haskell-cafe at haskell.org
> From: Snouser <linusoleander at gmail.com>
> Date: Fri, 18 Sep 2009 10:14:53 -0700 (PDT)
> Subject: Re: [Haskell-cafe] How to generate random string?
> 
> 
> 
> 
> Snouser wrote:
> > 
> > I need to generate a random string from 1 to 30.
> > 
> > This is the parts I've done so far.
> > 
> > unikString xs | let x = unsafePerformIO (randomRIO (1,30)) elem x xs = x :
> > unikString xs
> > 			  | otherwise = unikString xs
> > 
> > How do I proceed?
> > 
> > I need the string/list to look like this:
> > 
> > [1,9,3,6,2] et.c with only unik numbers.
> > 
> > Thanks!
> > 
> 
> I wasnt added to the mailinglist, but now I'm.
> 
> 
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>  
>  ** ACCEPT: CRM114 PASS osb unique microgroom Matcher ** 
> CLASSIFY succeeds; success probability: 1.0000  pR: 6.3668
> Best match to file #0 (nonspam.css) prob: 1.0000  pR: 6.3668  
> Total features in input file: 2688
> #0 (nonspam.css): features: 758386, hits: 2881904, prob: 1.00e+00, pR:   6.37 
> #1 (spam.css): features: 1686754, hits: 3078784, prob: 4.30e-07, pR:  -6.37 
>