in reply to Reversed .= operator

substr can do that easily: 
substr $string, 0, 0, $prefix;

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($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

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Re^2: Reversed .= operator
by 1nickt (Canon) on Apr 29, 2016 at 22:08 UTC

    Yes, of course, there is more than one way to do it. I would use 

    $string = $prefix . $string

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    over 
    substr $string, 0, 0, $prefix

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    myself (for readability, not because it's two fewer characters) ... but I want a (built-in) operator, dammit!


    The way forward always starts with a minimal test.
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      It's not the same. substr is a bit faster, probably because it doesn't create a new string?

      ($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

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        Is $string =~ s/^/$prefix/; about the same speed as the substr expression?

        To me, it would more signal the intent than substr does. Then again, so does the pesky dot-between-strings notation, which 1nickt doesn't want. :-) But, as with the substr, the =~ s/^// version doesn't require duplicating $string in your statement, which is one of the benefits of the suffixing .= operator.

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