Bug in constant overloading?

[p5pRT]

Migrated from rt.perl.org#3668 (status was 'resolved')

Searchable as RT3668$

[p5pRT]

From gnat@frii.com

  package NoBill;
 
  use overload;
  sub import {
  overload​::constant q => \&string_handler;
  }

  sub string_handler {
  my ($original, $perl_guess, $use) = @​_;
  if ($use eq 'qq') {
  $original =~ s/Windows/Winblows/g;
  }
  return $original;
  }
  1;

When I say

  perl -MNoBill -le 'print "Windows rocks"'

it fails to change the string "Windows" to "Winblows". This is
because $use is set to 'q' not 'qq'. Apparently a double-quoted
string with no interpolation or \ characters is interpreted as q() not
qq(). If I write it as qq() rather than with real double-quotes, $use
is set to 'qq'. If I put in \n at the end of the literally
double-quoted string, $use reports 'qq'.

Is this a bug in Perl, a bug in the documentation, or a bug in my
brain?

(tested with perl-5.6.0)

Nat
(observing the edict​: Post No Bills :-)

[p5pRT]

From [Unknown Contact. See original ticket]

On Aug 9, Nathan Torkington said​:

When I say

perl -MNoBill -le 'print "Windows rocks"'

it fails to change the string "Windows" to "Winblows". This is
because $use is set to 'q' not 'qq'. Apparently a double-quoted
string with no interpolation or \ characters is interpreted as q() not
qq(). If I write it as qq() rather than with real double-quotes, $use
is set to 'qq'. If I put in \n at the end of the literally
double-quoted string, $use reports 'qq'.

It's Perl compile-time optimization​:

  jeffp@​hut [12​:29am] ~ #102> perl -MO=Deparse
  @​array = ("hello", 'world', qq<what's>, q!up?!, "foo!\n");
  __END__
  @​array = ('hello', 'world', q[what's], 'up?', "foo!\n");
  - syntax OK

As Larry Rosler might say, why get Perl all primed for double-quotish
interpolation when it's not going to happen?

[p5pRT]

From [Unknown Contact. See original ticket]

Jeff Pinyan writes​:

It's Perl compile-time optimization​:

Yeah, but you didn't answer my question. When I'm overloading
strings, should it report the original type of string, should the
documentation say what's going to happen, or should I give up and go
warm the crack pipe?

Nat

[p5pRT]

From [Unknown Contact. See original ticket]

On Aug 9, Nathan Torkington said​:

Jeff Pinyan writes​:

It's Perl compile-time optimization​:

Yeah, but you didn't answer my question. When I'm overloading
strings, should it report the original type of string, should the
documentation say what's going to happen, or should I give up and go
warm the crack pipe?

Ah, I think the documentation should explicitly give a caveat re constant
strings without interpolation required.

That, or give a listing of local pagers. ;)

  $nat->pass($japhy,%|);

A beta patch is​:

  =item q

  to overload C<q>-quoted strings, constant pieces of C<qq>- and
  C<qx>-quoted strings and here-documents, or quoted strings requiring
  no interpolation beyond escaping C<\> and escaping the quoting
  delimiter,

If you don't like that wording, I cite the BUGS section​:

  This document is confusing. There are grammos and misleading language
  used in places. It would seem a total rewrite is needed.