[tz] tabs vs spaces

Tobias Conradi mail.2012 at tobiasconradi.com
Thu May 2 23:06:05 UTC 2013

On Fri, May 3, 2013 at 12:38 AM, Guy Harris <guy at alum.mit.edu> wrote:
> On May 2, 2013, at 2:59 PM, Tobias Conradi <mail.2012 at tobiasconradi.com> wrote:
>> "IANA and the tz database - diverging from Theory"
>> http://mm.icann.org/pipermail/tz/2011-September/008879.html
> Then perhaps it's time to retire Theory in favor of RFC 6557.
Or retire the RFC.

> "You can find it if you dig into the middle of the code directory" is not quite as much of a "mention" as, for example, "the theory behind the database is described in <a href="{some URL}">the Theory file</a>"

My mistake. Agreed.

>> Where is the "ultimate documentation of the time zone database"?
> Perhaps nowhere.  Perhaps a number of places, such as the various man pages for the technical details of the format of time zone data files and of the binary files produced by zic, and RFC 6557 for policies.

The man pages cannot be accessed with a browser and cannot be
html-href-linked, can they?

>> I didn't understand that benefit at all.
> The benefit of
>>>        It lets existing files (which have more than one tab in a row, at least for leading spaces) be read without having to reformat them.
> is "if we don't change zic to treat individual white-space characters as column separators, so that
>         <TAB>A<TAB><TAB>B
> is viewed as three columns, one with the value "A", one blank, and one with the value "B", then we don't change zic in such a way that it gets very confused when it reads the existing time zone rule files, and thus we don't have to change all our files to the new format, *and* we don't have to force anybody who's created their own time zone rule files to change *their* files".

Now understood as path-dependency, no benefit at time of creation.

>> OK, that is the current reason. But what might have been the reason
>> when zone.tab was established with single tab?
> Code to parse it was a bit quicker to whip up with that limitation, given that it was probably not viewed by its creator as being as "core" to the time zone database as the time zone data files?

Might contradict the claim by random832
1) In most languages, splitting up by
 'any whitespace' is the simplest thing in the world.
2) In C (where nothing is simple), you could
reuse the code from zic itself.

Tobias Conradi
Rheinsberger Str. 18
10115 Berlin


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