[tz] Tab/Space Formatting Inconsistency - Asia Ver 2023c
Brian Inglis
Brian.Inglis at Shaw.ca
Wed Dec 13 02:11:55 UTC 2023
On 2023-12-12 18:46, Paul Gilmartin via tz wrote:
> On 12/12/23 17:25:15, Paul Eggert via tz wrote:
>> ...
>> As Alois writes, this is merely a visual appearance issue; it doesn't affect
>> the meaning of the data.
> Sometimes it matters. "make" requires build rules to be introduced
> by tabs. not spaces. And I know a couple lexical analyzers which
> recognize spaces but not tabs as separating tokens.
>> Spaces are sometimes used instead of tabs, when using a tab would cause
>> columns or lines to not fit. For example, consider the line:
>> ...
>> Rule EgyptAsia 1957 only - May 10 0:00 1:00 S
>> ...
>> We prefer data to be 80 character columns or less for the usual reasons; see,
>> for example <https://www.emacswiki.org/emacs/EightyColumnRule>. So we use a
>> space instead of a tab there.
> Which says,
> “Thou shalt not cross 80 columns in thy file” originated from
> IBM 80 column punch cards, ...
> On IBM 80 column punch cards, the tab, 0x05 (rarely used), occupies
> only a single column, regardless of its appearance on output devices.
ITYM ...tab, 12-9-5 (EBCDIC 0x05 - rarely used),...
...I would go so far as to say never used except perhaps internally in software.
--
Take care. Thanks, Brian Inglis Calgary, Alberta, Canada
La perfection est atteinte Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add
mais lorsqu'il n'y a plus rien à retirer but when there is no more to cut
-- Antoine de Saint-Exupéry
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