Re: [SPAM UNSURE] Re: Reliable after-change-functions (via: Using incremental parsing in Emacs)

[Robert Pluim <rpluim@gmail.com>]

>>>>> On Thu, 02 Apr 2020 18:49:07 -0800, Stephen Leake <stephen_leake@stephe-leake.org> said:

    Stephen> Eli Zaretskii <eliz@gnu.org> writes:
    >>> From: Stefan Monnier <monnier@iro.umontreal.ca>
    >>> Date: Wed, 01 Apr 2020 22:46:18 -0400
    >>> Cc: emacs-devel <emacs-devel@gnu.org>
    >>> 
    >>> If the GC is the worry, we can use a function which encodes the
    >>> buffer using a given coding-system and returns a malloc'd array of bytes.
    >> 
    >> I think we should try to avoid both copying and encoding the text we
    >> send to the parser.  Both operations are expensive and require memory
    >> allocation.

    Stephen> I don't understand what the alternative is. The parser imposes the
    Stephen> reasonable requirement that the input text be utf-8 (or possibly some
    Stephen> other standard format). Emacs raw buffer text is not utf-8, so we must
    Stephen> do some encoding.

Itʼs pretty close, apart from raw bytes. How much of an imposition
would it be in practice to say 'source code must not contain raw bytes'?

    Stephen> If we try to pass a plain pointer to a point in the Emacs internal
    Stephen> buffer, there is no way to do that encoding.

As pointed out elsewhere, you'd have to take the gap into account, so
it would be two pointers and two lengths to describe the entire buffer
text.

Robert