Skip to content

Bug in sub? (PR#487)

3 messages · Trenkler, Dietrich, Torsten Hothorn, Peter Dalgaard

Original
Trenkler, Dietrich
# 
I suspect that there is bug in sub when using "?":
[1] "This is a bug, or isn't it?"
[1] "This is a bug?"


Regards,

  *** D.Trenkler ***

====================================================================
Dietrich Trenkler                   (trenkler@oec.uni-osnabrueck.de)
Statistik / Empirische Wirtschaftsforschung
Universitaet Osnabrueck
Rolandstrasse 8                           Phone: +49(0) 541-969-2753
D-49069 Osnabrueck                        Fax  : +49(0) 541-969-2745
GERMANY
====================================================================


--please do not edit the information below--

Version:
 platform = Windows
 arch = x86
 os = Win32
 system = x86, Win32
 status = 
 major = 1
 minor = 0.0
 year = 2000
 month = February
 day = 29
 language = R

Windows NT 4.0 (build 1381) Service Pack 3

Search Path:
 .GlobalEnv, Autoloads, package:base

-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-devel-request@stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
Torsten Hothorn
# 
R> string_"This is a bug?"
R> sub("[?]", ", or isn't it?", string)
[1] "This is a bug, or isn't it?"

works, has "?" a special meaning in regexp?

Torsten
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-devel-request@stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
Peter Dalgaard
# 
dtrenkler@nts6.oec.uni-osnabrueck.de writes:
Hmm. If there is a bug it may not where you think...

'?' is an operator of extended regular expressions, so you're not
looking for a question mark there:
[1] "This is a bug, or isn't it?"
[1] "This is a bug, or isn't it?"

One might expect that a null RE would always match the beginning of a
string, but it doesn't...