in reply to Re: Perl ignore arrow object operator in search/replace (s/searchregex/replacestring/)
in thread Perl ignore arrow object operator in search/replace

> There are no arrow operators in strings,

That's wrong! Variable interpolation does easily dereference hashes and arrays (i.e. within strings and substitutes). 

  DB<114> $h={a=>42}
 => { a => 42 }

  DB<115> "$h->{a}"
 => 42

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Though coderefs seem to be excluded. 

  DB<118> $sub=sub { "nope" }
 => sub { "???" }

  DB<119> "$sub->()"
 => "CODE(0xa5cc200)->()"

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But the @{[...]} ("local eval") trick always helps where a general /e would cause too much harm.

  DB<120> $_="X"
 => "X"

  DB<121> s/X/@{[ $sub->() ]}/
 => 1

  DB<122> $_
 => "nope"

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see also: s/RegEx/substitutions/: Variable interpolation and when to use /e - modifiers

Cheers Rolf

( addicted to the Perl Programming Language)

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Re^3: Perl ignore arrow object operator in search/replace (s/searchregex/replacestring/)
by tobyink (Canon) on Feb 17, 2014 at 20:06 UTC

    The arrow operator works in strings for dereferencing hash and array elements, but not for calling coderefs, and not for method calls.

    As well as the "@{[ ... ]}" trick, another option is "${\ ... }".

    use Moops; class Cow :rw { has name => (default => 'Ermintrude') }; say Cow->new->name
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      I'm not sure where you are correcting me... Did I say anything different?

      But I normally avoid (recommending) the scalar deref trick cause it can only return scalars (sic ;) which can byte you heavily...

      Cheers Rolf

      ( addicted to the Perl Programming Language)

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        I'm not sure why you think I'm correcting you... I was agreeing with you. (And confirming the bit about coderefs, and adding method calls to the list.)

        use Moops; class Cow :rw { has name => (default => 'Ermintrude') }; say Cow->new->name
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