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From: jerry <jdinardo@nycap.rr.com>
To: Christopher Lam <christopher.lck@gmail.com>
Cc: guile-user <guile-user@gnu.org>
Subject: Re: guile style
Date: Sat, 19 Jun 2021 08:16:39 -0400	[thread overview]
Message-ID: <1e959322-f5f8-9bc3-ae08-a30165f9f409@nycap.rr.com> (raw)
In-Reply-To: <CAKVAZZKUTHD9Tv82m=_Ar_QjP+tmDkMwAo_Gf6QHgsXqsimb2w@mail.gmail.com>

On 6/19/21 7:20 AM, Christopher Lam wrote:
> Agree set! is not a desirable form. It is not consistently optimisable. 
> I cannot find the reference in the manual.
> 
> Also consider the first form: you're building a list in 3 passes -- call 
> iota to generate a list, call filter to navigate the list again, then 
> fold to accumulate your answer. Therefore it's O(3N).
> 
> The preferred form is definitely from the little schemer.
> 
Haskell has something called stream fusion which can optimize the extra
passes out in many cases. I wonder if Guile or any of the other scheme
compilers can do that? As someone who has spent the majority of my life
writing high performance C and Fortran code, the inefficiencies in a lot
of functional programming is something I don't care for. On the other
hand, writing functional code is fun.




  reply	other threads:[~2021-06-19 12:16 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-19  0:55 guile style jerry
2021-06-19 10:25 ` Tim Van den Langenbergh
     [not found]   ` <CAGua6m1HSYGP6i60Qyj=sVAgeriOzZmb1abCtoxnTQQiOgyY-Q@mail.gmail.com>
2021-06-19 11:24     ` Fwd: " Stefan Israelsson Tampe
2021-06-19 11:31   ` jerry
2021-06-19 11:17 ` Ricardo Wurmus
2021-06-19 11:20 ` Christopher Lam
2021-06-19 12:16   ` jerry [this message]
2021-06-19 17:02     ` Zelphir Kaltstahl
2021-06-19 17:59     ` Linus Björnstam
2021-06-20  2:21       ` jerry

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