RetroBBS - comp.lang.scheme - Re: nice way to write (define) Slices in R7RS ?

nice way to write (define) Slices in R7RS ?

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Subject: nice way to write (define) Slices in R7RS ?
From: henhanna@gmail.com (Hen Hanna)
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by: Hen Hanna - Sun, 19 Jun 2022 01:37 UTC

this is Slices in Gauche... what 's a nice way to write (define) it ?

(define a '(a b c d e f g h i j k l m n o p q r s t u v w x y z))

(slices a 2) --> ((a b) (c d) (e f) (g h) (i j) (k l) (m n) (o p) (q r) (s t) (u v) (w x) (y z))

(slices a 3) --> ((a b c) (d e f) (g h i) (j k l) (m n o) (p q r) (s t u) (v w x) (y z))

(slices a 4) --> ((a b c d) (e f g h) (i j k l) (m n o p) (q r s t) (u v w x) (y z))

(slices a 5) --> ((a b c d e) (f g h i j) (k l m n o) (p q r s t) (u v w x y) (z))

Re: nice way to write (define) Slices in R7RS ?

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by: Paul Rubin - Sun, 19 Jun 2022 02:19 UTC

Re: nice way to write (define) Slices in R7RS ?

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Subject: Re: nice way to write (define) Slices in R7RS ?
From: henhanna@gmail.com (Hen Hanna)
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by: Hen Hanna - Sun, 19 Jun 2022 05:03 UTC

On Saturday, June 18, 2022 at 6:37:32 PM UTC-7, Hen Hanna wrote:
> this is Slices in Gauche... what 's a nice way to write (define) it ?
>
>
> (define a '(a b c d e f g h i j k l m n o p q r s t u v w x y z))
>
> (slices a 2) --> ((a b) (c d) (e f) (g h) (i j) (k l) (m n) (o p) (q r) (s t) (u v) (w x) (y z))
>
> (slices a 3) --> ((a b c) (d e f) (g h i) (j k l) (m n o) (p q r) (s t u) (v w x) (y z))
>
> (slices a 4) --> ((a b c d) (e f g h) (i j k l) (m n o p) (q r s t) (u v w x) (y z))
>
> (slices a 5) --> ((a b c d e) (f g h i j) (k l m n o) (p q r s t) (u v w x y) (z))

(not homework)

what i'd do... use DO and var RES,
get a slice with Take and push it onto RES
recurse down using Drop

at the end , return (reverse! res)

------------ if there's another way taht's clever, interesting, .... pls let me know !!!

Machines take me by surprise with great frequency. -- Alan Turing

devel / comp.lang.scheme / Re: nice way to write (define) Slices in R7RS ?

Subject	Author
nice way to write (define) Slices in R7RS ?	Hen Hanna
Re: nice way to write (define) Slices in R7RS ?	Paul Rubin
Re: nice way to write (define) Slices in R7RS ?	Hen Hanna