Re^3: 'g' flag w/ 'qr'

[Athanasius]

I’m guessing you’re running a fairly old version of Perl? On 5.20.2, I get:

Unknown regexp modifier "/g" at 1645_SoPW.pl line 18, near "= "

— which is clear. But on 5.12.3, I get:

Bareword found where operator expected at 1645_SoPW.pl line 18, near "
+qr{ (\w+) }gx"
syntax error at 1645_SoPW.pl line 18, near "qr{ (\w+) }gx"

— which isn’t. In any case, the “deprecated” message you’re seeing is related only indirectly to the presence of a /g modifier on a qr// term. The Perl compiler is simply confused as to what the syntax is supposed to mean, and its (incorrect) guess leads it to find a construct which you never intended and which happens to be deprecated.

Actually, the qr// syntax was introduced in Perl 5.005,¹ which was released in 1998. The first edition of the Camel Book to document qr// was the third edition, published in July, 2000 (4 months after the release of Perl 5.6). The section “Pattern-Matching Operators” in Chapter 5 draws a distinction between those modifiers which apply to a regex (are are therefore applicable to qr//) and those which apply to an operator (and are therefore applicable only to m// and s///).² The /g modifier falls in the second category. So, AFAICT, putting a /g modifier on a qr// term is not “deprecated,” as it was never allowed in the first place.

¹Update (May 30, 2016): See perl5005delta#New qr// operator.
²Compare the tables on pages 147 and 150.

Hope that helps,