I've another more straightforward implementation lol. More easy lol.
I'll push it tomorrow 
Just 
Singleton [x] = True
Singleton _ = False 

Massyl

On 15 oct. 2013, at 18:42, "Antoine R. Dumont" <notifications@github.com> wrote:

> In src/Huffman.hs:
> 
> >  
> >  singleton :: [CodeTree] -> Bool
> > -singleton = ((== 1) . length)
> > +singleton xs = (null $ tail xs) && (length xs == 1)
> Great, deal with empty list!
> 
> —
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