Hi

according to perlop#s/PATTERN/REPLACEMENT/ a double eval isn't a double eval but the eval of an interpolation

e    Evaluate the right side as an expression.
ee   Evaluate the right side as a string then eval the result.

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At least that's how I understand the distinction between "evaluate as an expression" and "evaluate as a string"...

Problem is that I can't see this distinction, ee produces just

eval ( eval 'RHS' )

eval do { RHS } ¹

for me and not

eval "RHS".

Or what is meant here, if "evaluate as a string" isn't supposed to mean "string resp. var interpolation", what else?

some snippets as demonstration

  DB<135> $_='x'
 => "x"

  DB<136> $a='$b'; $b="B"
 => "B"

  DB<137> s/x/$a.$a/r            # -> "$a.$a" (interpolation)
 => "\$b.\$b"

  DB<138> s/x/$a.$a/re           # -> eval '$a.$a'
 => "\$b\$b"

  DB<139> s/x/$a.$a/ree          # -> eval "\$b\$b" not eval "\$b.\$b"

Scalar found where operator expected at (eval 106)[(eval 105)[multi_pe
+rl5db.pl:644]:2] line 1, near "$b$b" ...

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but

  DB<140> s/x/$a.'.'.$a/ree      # -> eval "\$b.\$b"
 => "BB"

  DB<141> s/x/$a.'.'.$a/re       # -> eval '$a.\'.\'.$a'
 => "\$b.\$b"

  DB<142> s/x/$a.'.'.$a/r        # -> "$a.'.'.$a"
 => "\$b.'.'.\$b"

  DB<143> eval "\$b.'.'.\$b"     # what perldoc predicts for line 140
 => "B.B"

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Cheers Rolf

(addicted to the Perl Programming Language and ☆☆☆☆ :)

¹) updated: the RHS is precompiled, but eval 'RHS' means runtime compilation

In reply to perldoc of s///ee wrong or just misleading? by LanX

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