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Re: Choosing a data structure for cache of multiple fake cursors.
From: |
Eli Zaretskii |
Subject: |
Re: Choosing a data structure for cache of multiple fake cursors. |
Date: |
Tue, 25 Dec 2018 15:36:26 +0200 |
> Date: Mon, 24 Dec 2018 22:18:12 -0800
> From: Keith David Bershatsky <address@hidden>
>
> The elements of the cache are as follows: x [int]; fx [frame x | int]; y
> [int]; fy [frame y | int]; hpos [int]; vpos [int]; h [height | int];
> cursor_type [int]; cursor_width [int]; foreground [vector of 3 doubles];
> background [vector of 3 doubles]; active_p [bool]; minimal_p [bool]; flavor
> [int]; posint [int].
You didn't describe what each element means.
> In this example, we want to find all VPOS entries in the cache for 5, 8 and
> 25 and do two things: (i) erase the fake cursors on the line; and, (2)
> recalculate/redraw the fake cursors on those lines based on the new layout.
>
> Assuming that we are dealing with a potential of 200+ fake cursors on a
> visible window, what is the best data structure for performance and ease of
> add/removing elements (with 15 sub-elements)?
If the number of elements is fixed, then a vector would be more
convenient, but other than that, I don't see why it would be a poor
choice to use a list. We access and modify lists (and other Lisp
objects) from C code all the time, to say nothing of the fact that
these objects and the primitive operations on them are implemented in
C to begin with.