Re: Identifying Reverse Position of Specific Character in a String

sub find_gap_ends
{
    local $_ = shift;
    my @gap_end_pos;
    while ( /N(?!N)/g )
    {
        push @gap_end_pos, pos;
    }
    @gap_end_pos
}
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Comment on Re: Identifying Reverse Position of Specific Character in a String Download Code

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Re^2: Identifying Reverse Position of Specific Character in a String by ikegami (Patriarch) on Aug 25, 2006 at 19:31 UTC
Use `for (shift)` instead of `local $_ = shift` to avoid bugs.	[reply] [d/l] [select]
Re^3: Identifying Reverse Position of Specific Character in a String by jdporter (Paladin) on Aug 25, 2006 at 19:56 UTC
There's no benefit to that in this case, since the function makes no attempt to alter `$_`. Furthermore, using the `for(shift)` idiom with code that does modify `$_` is dangerous, unless your intent is to modify `$_[0]`. As for `pos`, one of the lessons you do (or should) learn early in your Perl edjication is to call `pos` as soon after the regex that sets it as possible — ideally, immediately after it. Otherwise, you're taking a gamble. We're building the house of the future together.	[reply] [d/l]
Re^4: Identifying Reverse Position of Specific Character in a String by ikegami (Patriarch) on Aug 25, 2006 at 20:02 UTC
since the function makes no attempt to alter $_. Odd, I see two things that modify it. An assignment, and the regexp alters the associated `pos`. The point of local is to protect the caller, but it doesn't necessarily do so in this situation.	[reply] [d/l]
Re^5: Identifying Reverse Position of Specific Character in a String by jdporter (Paladin) on Aug 25, 2006 at 20:18 UTC