Print Page - Stitching lists together

Title: Stitching lists together
Post by: cormullion on April 23, 2010, 10:56:31 AM

Given two lists, what's the easiest way to splice them together.

From this:

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(set 'a '(fred jim bob))
(set 'b '(1 2 3))

to this

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((fred 1) (jim 2) (bob 3))

... coming back to some newLISP coding after a few weeks away and I think I'm rusty...

Title: Re: Stitching lists together
Post by: m i c h a e l on April 23, 2010, 11:15:46 AM

This does the trick:

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(map list a b)

I'm sure there's an even better way, though.

m i c h a e l

Title: Re: Stitching lists together
Post by: cormullion on April 23, 2010, 12:14:08 PM

Thanks! I've forgotten more than I thought! :)

Title: Re: Stitching lists together
Post by: Sammo on April 23, 2010, 01:53:44 PM

Another solution:

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(transpose (list a b))
>((fred 1) (jim 2) (bob 3))

and applying transpose again has the effect of undoing:

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(transpose (transpose (list a b)))
>((fred jim bob) (1 2 3))

Title: Re: Stitching lists together
Post by: cormullion on April 23, 2010, 11:18:56 PM

like it!

Title: Re: Stitching lists together
Post by: Tim Johnson on April 28, 2010, 08:22:27 AM

I use this function

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(define (merge)(transpose (args)))

Lutz is a man of few words ...

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