perlop: properly document s///e modifier #23656
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- s///e is not limited to expressions. The replacement part can contain
any number of statements, like 'do { ... }'.
- s///ee does not treat the RHS as a string. The RHS is parsed as a
block (like s///e), but then the resulting string is eval()'d.
- You can have more than two e's. Each additional 'e' wraps another
eval() around the result.
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If it behaves as a |
Yes: use v5.36;
sub Honk::DESTROY {
say "$_[0] destroyed";
}
my $string = "hello";
$string =~ s{([eo])}{
say "replacing '$1'";
my $obj = bless {}, 'Honk';
"_"
}eg;
say "done: $string";
say '$obj is ', eval('$obj') // "not in scope: $@";Output:
Only in the sense that every |
| to be C<eval>ed. | ||
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| That is, C<s/FOO/BAR/e> will compute the replacement string at match time as if | ||
| by C<do { BAR }> (see L<perlfunc/do BLOCK>). Each additional C<e> modifier |
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The "by" here confuses me. Maybe "as if it had been written as"
| That is, C<s/FOO/BAR/e> will compute the replacement string at match time as if | ||
| by C<do { BAR }> (see L<perlfunc/do BLOCK>). Each additional C<e> modifier | ||
| wraps a call to C<eval> around the result: C<s/FOO/BAR/ee> will compute the | ||
| replacement string as if by C<eval(do { BAR })>, C<s/FOO/BAR/eee> as if by |
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Again, the by doesn't sound good to me
| result. | ||
| e Evaluate the right side as a block of code. | ||
| ee Evaluate the right side as a block of code, then eval() | ||
| the resulting string. |
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Where exactly in the source code does this evaluation of the RHS as a block of code rather than as either an expression or a string is enforced? (I'm asking this not to quibble, but just to know your reference point.)
And I wrote a perfect example years ago: |
s///eis not limited to expressions. The replacement part can contain any number of statements, likedo { ... }.s///eedoes not treat the RHS as a string. The RHS is parsed as a block (likes///e), but then the resulting string iseval()d.es. Each additionalewraps anothereval()around the result.