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Re: string-map arg order
From: |
Alex Shinn |
Subject: |
Re: string-map arg order |
Date: |
06 Sep 2001 13:16:08 -0400 |
User-agent: |
Gnus/5.0808 (Gnus v5.8.8) Emacs/21.0.104 |
>>>>> "Dirk" == Dirk Herrmann <address@hidden> writes:
>> Note that we can also use this same approach when resizing utf8
>> strings, so we can get back the O(n) time on string-for-each
>> and kin. Thanks for pointing that out :)
Dirk> Sorry, no :-) Look at the following pseudo code that runs in
Dirk> a single-threaded guile and tell me how you would implement
Dirk> string-for-each in O(n) with a multi byte encoding...
Dirk> (define s <some string>)
Dirk> (define (foo c)
Dirk> (string-set! s (random-index (length s)) (random-character)))
Dirk> (string-for-each foo s)
Well, the looping of string-for-each is O(n)... in your example, the
inside of the loop happens to be an O(n) computation (in a style we
would have to make clear is inefficient).
When I said string-for-each is O(n), I meant the overhead involved, I
did not mean you could magically write
(string-for-each (lambda (x) (some-huge-computation-of x)) str)
and always get it to run in O(n) time :)
--
Alex Shinn <address@hidden>
- Re: string-map arg order, Dirk Herrmann, 2001/09/03
- Re: string-map arg order, Alex Shinn, 2001/09/03
- Re: string-map arg order, Dirk Herrmann, 2001/09/03
- Re: string-map arg order, Alex Shinn, 2001/09/03
- Re: string-map arg order, Dirk Herrmann, 2001/09/04
- Re: string-map arg order, Alex Shinn, 2001/09/04
- Re: string-map arg order, Dirk Herrmann, 2001/09/05
- Re: string-map arg order, Alex Shinn, 2001/09/05
- Re: string-map arg order, Dirk Herrmann, 2001/09/06
- Re: string-map arg order,
Alex Shinn <=
- Re: string-map arg order, Dirk Herrmann, 2001/09/06
- Re: string-map arg order, Alex Shinn, 2001/09/06
- Re: string-map arg order, Dirk Herrmann, 2001/09/06
- Re: string-map arg order, Alex Shinn, 2001/09/06
- Re: string-map arg order, Dirk Herrmann, 2001/09/06
- Re: string-map arg order, Marius Vollmer, 2001/09/05
- Re: string-map arg order, Dirk Herrmann, 2001/09/06
- Re: string-map arg order, Marius Vollmer, 2001/09/06
- Re: string-map arg order, Neil Jerram, 2001/09/04
Re: string-map arg order, Gary Houston, 2001/09/04