From: Stefan Monnier <monnier@IRO.UMontreal.CA>
To: raman@google.com (T.V Raman)
Cc: 17181-done@debbugs.gnu.org
Subject: bug#17181: 24.4.50; previous-single-property-change: odd behavior
Date: Thu, 03 Apr 2014 22:27:56 -0400 [thread overview]
Message-ID: <jwvwqf5ltl1.fsf-monnier+emacsbugs@gnu.org> (raw)
In-Reply-To: <p91lhvlx6n3.fsf@lapdog.roam.corp.google.com> (T. V. Raman's message of "Thu, 03 Apr 2014 17:47:28 -0700")
tags 17181 notabug
thanks
> (put-text-property (point) (point-max) 'test t)
> Move point to the front of "bar" ie point is at the beginning of the
> line.
> (get-text-property (point) 'test) returns T as expected.
> (point) evaluates to 6
> Consequently, I'd expect
> (previous-single-property-change (point) 'test) to return 5
> instead you get: nil
Buffer positions are *between* characters. `get-text-property' gets you
the value of the property on "the character after point".
`previous-single-property-change' gets you the nearest change on
*previous* characters. The property above is nil between point-min and
point, so previous-single-property-change finds no change at all.
The off-by-one error is in your expectations :-(
Stefan
next prev parent reply other threads:[~2014-04-04 2:27 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-04 0:47 bug#17181: 24.4.50; previous-single-property-change: odd behavior T.V Raman
2014-04-04 2:27 ` Stefan Monnier [this message]
2014-04-04 15:18 ` T.V Raman
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