Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Might a Monk have words to reduce my rage over the fact that '\\' single quotes don't interpolate: 
  DB<11> print '\\n';
\n
  DB<12> print '\n';
\n

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<<'HEREDOC' does work, however.

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Re: slashes in single-quoted string
by wind (Priest) on Apr 29, 2011 at 20:46 UTC

    I agree that it is at first glance, it appears odd that '\\foo' and '\foo' are equivalent. But this is a necessary exception if we want single quoted strings to be able to contain any character without special jury rigging.

    It's not that hard to remember that if you use q{}, that you can escape [\{}] in the string, or if you use '', you can escape [\']. The fact that heredocs don't require you to escape the 'HEREDOC' should be fairly obvious I believe.

    I'm therefore for maintaining the status quo, although I do appreciate the discussion.

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Re: slashes in single-quoted string
by trwww (Priest) on Apr 29, 2011 at 21:34 UTC
    For me, its enough to have a personal rule that if a string contains ' (or " when I'm interpolating), I then use the q and qq operators. This way I never have to escape a character in a string.
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      > This way I never have to escape a character in a string. 

        DB<100> print q{\n}
\n
  DB<101> print q{\\n}
\n
  DB<102> print q{\\\n}
\\n

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      Cheers Rolf

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Re: slashes in single-quoted string
by LanX (Saint) on Apr 29, 2011 at 21:13 UTC
    if '\'' means q{'} what do you expect '\\' to mean?

    Cheers Rolf

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      I'm not sure what the OP wants to achieve with the post (simply express anger, or suggest this should be changed in an upcoming release(?)), but I guess the idea is that '\\' (or q{\\}) would mean two backslashes — i.e. you simply cannot escape the delimiter, which means you'd just have to choose a different delimiter (using q) in those cases.

      Typical pitfall with the current workings is that you tend to forget to escape the double backslashes in UNC paths, such as 

      my $dir = q{\\\\dfsshare\foo\bar};
            ^ ^

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        IMHO it's impossible to disable "escaping" and allowing arbitrary character sequences.

        I mean by using an alternate delimiter like q{} or q// the problem is just postponed.

          DB<105> print q{\}}
}

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        Then the only possibility left would be concatenating with a constant representing the delimiter:

         eval( '$string=' . QUOTE . 'abc' . QUOTE );

        instead of  eval( '$string=\'abc\'' );

        Possible ... but desirable?

        Cheers Rolf

        UPDATE: or eval( '$string=' . q{'} . 'abc' . q{'} );

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Re: slashes in single-quoted string
by Anonymous Monk on Apr 30, 2011 at 00:46 UTC
    Might a Monk have words to reduce my rage over the fact that '\\' single quotes don't interpolate:

    Get over it? If I understood better why this RFC causes the rage I might have different words :)

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Re: slashes in single-quoted string
by Anonymous Monk on Apr 29, 2011 at 20:20 UTC
    err.. what I mean is that in perl 5, I am angry cause '\\' is '\'.
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