Re: G_UTF8String: Boxed Type Proposal

[Randall Sawyer <srandallsawyer hushmail me>]

On 03/17/2016 09:30 AM, Matthias Clasen wrote:
> Hi Randall,
>
> thanks for contributing!
Pleased to be of service! Looking forward to learning how folks work 
together in this community.
> > I believe that you haven't found such a proposal because most people
> > don't see much use in a separate boxed type for utf8 strings. Every
> > string we pass around in GLib and GTK+, and every char * in their APIs
> > is expected to be in utf8. The few exceptions to this rule are
> > explicitly documented.
There already is GString. It dynamically allocates its contents while 
keeping track of the number of bytes required - but not for the number 
of characters it contains.
> The main reason you mention for wanting such a type is to do away with
> the need for repeatedly calculating the character count. I think this
> falls into the same category as the length of the string in bytes - C
> doesn't have counted strings either, and expects you to just call
> strlen() over and over again. In practice, most strings we're handling
> are short enough for this to not be much of an issue.
For interactive applications which employ text-oriented widgets, there 
is a need to keep track of utf-8 character lengths for rendering 
purposes - text selection, etc. Each time this is called for, code needs 
to be written for such management. Take a look at gtkentrybuffer.c for 
example. I see a call for the provision of core code which handles this 
overhead repeatedly for these sorts of demands.
> GLib already provides a number of utilities for dealing with utf8
> strings in terms of characters, such as g_utf8_strlen,
> g_utf8_substring, g_utf8_find_next/prev_char. We can certainly discuss
> adding to that list, if there are glaring omissions.
As I mentioned above, there is GString with its limitations. My intent 
in presenting the possibility of "G_UTF8String" is to combine the 
dynamic allocation provided by GString while employing in the background 
these very utilities you mention.

Here is the vision: Once raw string data - or gunichar value - has been 
passed and validated into the construction of a "G_UTF8String" 
structure, then contents of two-or-more of these can be easily combined 
without the need for additional measuring or validating.

I have cloned a copy of glib-2.47.92. I am currently documenting the 
source code I have written.

I'll let you know when I have posted my first patch.