[Python-3000] Lines breaking

Alexandre Vassalotti alexandre at peadrop.com
Tue May 29 17:56:27 CEST 2007

On 5/29/07, "Martin v. Löwis" <martin at v.loewis.de> wrote:
> > The change would extend the line breaking behavior to three other
> > ASCII characters:
> >   NEL "Next Line" 85
> >   VT "Vertical Tab" 0B
> >   FF "Form Feed" 0C
> Of these, NEL is not an ASCII character, so Guido's "no change
> for ASCII-only text" requirement doesn't apply to text containing
> NEL.

Right. It is defined in the ISO control function standard (ISO 6429).
I have been duped by the format of table 5-1 in the Unicode standard.

> > Of course, it is not really necessary to change, but I think full
> > conformance to the standard [1] could give Python better support of
> > multilingual texts. However, full conformance would require a good
> > amount of work. So, it is true that it is probably better to postpone
> > it until someone complaint.
> Can you please point to the chapter and verse where it says that VT
> must be considered? I only found mention of FF, in R4.

Right again. (It is not my day today...) I should had read more
throughly, instead relying on the table.

Here the two sections for readline and writeline:

  R4 A readline function should stop at NLF, LS, FF, or PS. In the
     typical implementation, it does not include the NLF, LS, PS, or
     FF that caused it to stop.

  R4a A writeline (or newline) function should convert NLF, LS, and PS
      according to the conventions just discussed in "Converting to
      Other Character Code Sets."

-- Alexandre

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