Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.os.linux.advocacy > #591802

Re: US-ASCII is a subset of the set of Unicode code points.

Show all headers | View raw

On 2021-08-06, FR <fr@random.info> wrote:

> On Fri, 06 Aug 2021 17:36:37 +0200, R.Wieser wrote:
>
>>> As far as I know, the first 32 [ code points ] (except CR and LF)
>>> are just dead space.  Is this correct ?
>> 
>> No.  All of those have definite meanings.  
>
> According to the link that I cited, in Unicode the meanings,
> outside of an application, are not always the same as the original:
>
>
> "Unicode specifies semantics for the following control characters:
>  
> ASCII control characters: 
>
> HT and SP are considered whitespace.
>
> LF, VT, FF and CR are considered whitespace, and also mandatory line breaks
> in the line breaking algorithm.
>
> FS, GS, RS and US are considered separators in the bi-directional algorithm."
>
>
> Thus if I encounter an HT control code in some UTF-8 file
> then I should process that code as whitespace.
>
> But a specific application may choose to use the HT control
> code for some other purpose.

Think of HT as the TAB key on an old-fashioned typewriter.
Traditionally, it means "go to the next column of a multi-column
display".  Some file formats (TSV, tab-separated variables) use
HT as a field separator.

VT (vertical tab) isn't used much; it would be useful when
printing on pre-printed special forms.

CR traditionally means return to the start of the current line,
while LF means move to the same position on the next line.
These conventions are somewhat fluid; either might be interpreted
as CRLF, which is guaranteed to get you to the beginning of the
next line.

FF means go to the start of a new page.  In a world where data
is paginated (admittedly less common nowadays), this is significant.

To sum up, there is whitespace and there is whitespace.  The
differences between the various characters may be subtle, but
that doesn't mean that you should treat them all the same.
Each has its own special use.

-- 
/~\  Charlie Gibbs                  |  They don't understand Microsoft
\ /  <cgibbs@kltpzyxm.invalid>      |  has stolen their car and parked
 X   I'm really at ac.dekanfrus     |  a taxi in their driveway.
/ \  if you read it the right way.  |    -- Mayayana

Back to comp.os.linux.advocacy | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Any Unicode Experts? FR <fr@random.info> - 2021-08-06 14:39 +0000
  Re: Any Unicode Experts? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2021-08-06 14:51 +0000
    Re: Any Unicode Experts? FR <fr@random.info> - 2021-08-06 15:01 +0000
  Re: Any Unicode Experts? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2021-08-06 14:54 +0000
  US-ASCII is a subset of the set of Unicode code points. Jeff-Relf.Me  @. - 2021-08-06 08:15 -0700
    Re: US-ASCII is a subset of the set of Unicode code points. "R.Wieser" <address@not.available> - 2021-08-06 17:36 +0200
      Re: US-ASCII is a subset of the set of Unicode code points. FR <fr@random.info> - 2021-08-06 15:49 +0000
        Re: US-ASCII is a subset of the set of Unicode code points. Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2021-08-06 16:14 +0000
        Re: US-ASCII is a subset of the set of Unicode code points. "R.Wieser" <address@not.available> - 2021-08-06 18:48 +0200
        Re: US-ASCII is a subset of the set of Unicode code points. Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2021-08-06 17:25 +0000
          Re: US-ASCII is a subset of the set of Unicode code points. FR <fr@random.info> - 2021-08-06 17:52 +0000
          Re: US-ASCII is a subset of the set of Unicode code points. FR <fr@random.info> - 2021-08-06 17:57 +0000
  Re: Any Unicode Experts? Eli the Bearded <*@eli.users.panix.com> - 2021-08-06 20:27 +0000
    Re: Any Unicode Experts? The Natural Philosopher <tnp@invalid.invalid> - 2021-08-07 09:36 +0100
      Re: Any Unicode Experts? Steve Carroll <frelwizzen@gmail.com> - 2021-08-07 04:41 -0700
      Re: Any Unicode Experts? Eli the Bearded <*@eli.users.panix.com> - 2021-08-08 04:32 +0000
        Re: Any Unicode Experts? rbowman <bowman@montana.com> - 2021-08-07 22:50 -0600
          Re: Any Unicode Experts? jak <nospam@please.ty> - 2021-08-08 20:32 +0200
            Re: Any Unicode Experts? rbowman <bowman@montana.com> - 2021-08-08 18:00 -0600
              "while(1);" borks Visual Studio. Jeff-Relf.Me  @. - 2021-08-08 18:11 -0700
                Re: "while(1);" borks Visual Studio. rbowman <bowman@montana.com> - 2021-08-08 22:19 -0600
                Re: "while(1);" borks Visual Studio. Soviet_Mario <SovietMario@CCCP.MIR> - 2021-08-16 16:06 +0200
                Re: "while(1);" borks Visual Studio. jak <nospam@please.ty> - 2021-08-10 18:02 +0200
                while(malloc(666)); Jeff-Relf.Me  @. - 2021-08-10 09:28 -0700
                Re: while(malloc(666)); jak <nospam@please.ty> - 2021-08-10 18:39 +0200
                Re: "while(1);" borks Visual Studio. Smit <frelwizzen@gmail.com> - 2021-08-10 20:53 -0700
              Re: Any Unicode Experts? Stephen Carrolll <frelwizzen@gmail.com> - 2021-08-08 18:56 -0700
              Re: Any Unicode Experts? jak <nospam@please.ty> - 2021-08-09 07:28 +0200
                Re: Any Unicode Experts? rbowman <bowman@montana.com> - 2021-08-09 07:56 -0600
                Re: Any Unicode Experts? Dustin the dude with the stuck floppy <frelwizzen@gmail.com> - 2021-08-09 20:49 -0700
                Re: Any Unicode Experts? jak <nospam@please.ty> - 2021-08-10 10:33 +0200
                Re: Any Unicode Experts? The Natural Philosopher <tnp@invalid.invalid> - 2021-08-10 12:49 +0100
                Re: Any Unicode Experts? jak <nospam@please.ty> - 2021-08-10 15:26 +0200
                Re: Any Unicode Experts? vallor <vallor@cultnix.org> - 2021-08-10 13:43 +0000
                Re: Any Unicode Experts? rbowman <bowman@montana.com> - 2021-08-10 21:12 -0600
                Re: Any Unicode Experts? The Natural Philosopher <tnp@invalid.invalid> - 2021-08-11 12:25 +0100
                Re: Any Unicode Experts? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2021-08-11 16:52 +0000
                Re: Any Unicode Experts? jak <nospam@please.ty> - 2021-08-11 20:19 +0200
                Re: Any Unicode Experts? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2021-08-12 16:37 +0000
                Re: Any Unicode Experts? jak <nospam@please.ty> - 2021-08-12 20:32 +0200
                Re: Any Unicode Experts? rbowman <bowman@montana.com> - 2021-08-12 20:40 -0600
                Re: Any Unicode Experts? Dustin who does stuff with miceless computers <frelwizzen@gmail.com> - 2021-08-13 06:19 -0700
                Re: Any Unicode Experts? STALKING_TARGET_02 <frelwizzen@gmail.com> - 2021-08-13 03:41 -0700
                Re: Any Unicode Experts? Andreas Kohlbach <ank@spamfence.net> - 2021-08-10 16:11 -0400
                Re: Any Unicode Experts? DFS <nospam@dfs.com> - 2021-08-09 11:32 -0400
  Re: Any Unicode Experts? rbowman <bowman@montana.com> - 2021-08-06 18:19 -0600
  Re: Any Unicode Experts? Delimited <tabz334@rozlnk.net> - 2021-08-08 00:21 -0400
    Re: Any Unicode Experts? Joel <joelcrump@gmail.com> - 2021-08-08 00:29 -0400
    Re: Any Unicode Experts? Stéphane CARPENTIER <sc@fiat-linux.fr> - 2021-08-08 16:20 +0000
    Re: Any Unicode Experts? Stéphane CARPENTIER <sc@fiat-linux.fr> - 2021-08-08 16:28 +0000

csiph-web