inits

Josef Svenningsson josef.svenningsson at gmail.com
Sat Apr 8 19:08:29 EDT 2006


On 4/8/06, Tim Toorop <timtoorop at quicknet.nl> wrote:
> On the other hand, I think the new spiffy inits is quite clear once you
> notice why its  map (const xn) $ undefined:xn
>

I think it would be even clearer if it were defined like this:

> inits xs = zipWith take [0..] $ map (const xs) xs

That way you don't have this ugly special case for the first element
in the list. But there is an even better advantage: it is strict
again! So it's termination properties are exactly like the Prelude
one. This version *can* be used as a drop-in replacement of the
Prelude version.

Cheers,

/Josef


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