Re: How to add pseudo vector types

[Eli Zaretskii]

> From: Fu Yuan <casouri@gmail.com>
> Date: Tue, 3 Aug 2021 07:53:54 -0400
> Cc: stephen_leake@stephe-leake.org, cpitclaudel@gmail.com,
>  monnier@iro.umontreal.ca, emacs-devel@gnu.org
> 
> Oh no, I don’t mean that. I meant that, for example, functions like 
> node_start_byte, which returns the byte position of the beginning of the 
> node, will now be node_start_pos, which returns a point position.

That's called "character position".  Let's use the accepted
terminology, to minimize misunderstandings.

So in what sense are character positions easier to use than byte
positions?

> And if I want the byte position of the beginning of the node, I can use 
> (position-to-byte (tree-sitter-node-start-pos node))

Caveat: position-to-byte can be expensive.  So in time-critical code,
such as the display engine, we keep both character position and byte
position, and update them in sync.  Then you can use whichever is
easier in each case.