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Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams
From: |
Michael Heerdegen |
Subject: |
Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams |
Date: |
Thu, 15 Sep 2016 23:07:17 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) |
Clément Pit--Claudel <address@hidden> writes:
> > but the same applies to a list.
>
> Not exactly: the list needs to be fully built before you iterate over
> it. That's when the memory problems occur. So yes, during iteration
> you can discard the cons cells that you've already seen in both cases,
> but in the list case these cells need to all be constructed and kept
> in memory beforehand.
But I think what John said is still a valid argument: If you construct a
stream of lines of a process's output (just for example), of, say, 10000
lines, you create 10000 new objects (strings), and you discard 10000 - n
of them. They all need to be garbage collected. This will not only
take a large amount of time - garbage collection happens not all the
time, so memory will be filled to a certain amount as well. But I think
the impact of garbage collection of that many objects is a more serious
problem than memory usage anyway.
Instead, a simple loop incrementing a position variable or something
like that might be more appropriate (efficient).
Michael.
- [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, Michael Heerdegen, 2016/09/13
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, Clément Pit--Claudel, 2016/09/13
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, Michael Heerdegen, 2016/09/13
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, Clément Pit--Claudel, 2016/09/13
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, Michael Heerdegen, 2016/09/14
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, Clément Pit--Claudel, 2016/09/14
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, John Mastro, 2016/09/14
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, Clément Pit--Claudel, 2016/09/14
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, John Mastro, 2016/09/15
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams,
Michael Heerdegen <=
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, Clément Pit--Claudel, 2016/09/15
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, Michael Heerdegen, 2016/09/15
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, Clément Pit--Claudel, 2016/09/15
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, Michael Heerdegen, 2016/09/14
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, Clément Pit--Claudel, 2016/09/14
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, Nicolas Petton, 2016/09/15
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, Michael Heerdegen, 2016/09/15
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, Nicolas Petton, 2016/09/15
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, Michael Heerdegen, 2016/09/15
- Re: [PATCH] Elpa: Pinpoint semantics of `seq-subseq' for streams, John Wiegley, 2016/09/13