in reply to Splitting a comma-delimited string where a substring could contain commas

I need to split a string by commas, but excluding any commas between parethesis

Here's a start, which doesn't use lookahead assertions. It works on your tests case, but I would throw more tests cases at it before putting it into production. 

local $_ = "this, that, those, these (not enough, nope, never), there"
+;

while ( /(?:^|, )([^,]+\(.*?\)|[^,]+)/g ) {
    print $1, "\n";
}

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You have to understand a bit about backtracking to get how this works. It proceeds by trying to match, in this order
  1. at the beginning of a string, a word followed by a parenthetical
  2. at the beginning of a string, a word
  3. following ", ", a word followed by a parenthetical
  4. following ", ", a word

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Re: Re: Splitting a comma-delimited string where a substring could countain commas
by samtregar (Abbot) on May 03, 2002 at 19:09 UTC
    That looks pretty good, but it doesn't deal with multiple levels of parens. I think Text::Balanced is really the better solution.

    -sam

[reply]
      ... but it doesn't deal with multiple levels of parens.

      Coding now to deal with nested parens would be solving a problem that hasn't been presented. There might or might not be nested parens in the data. I'd wait for the "customer" to clarify their requirements before hitting this with a larger hammer. YMMV.

[reply]
      local $_ = "this, (that, those), these ((not enough, (nope)), never), 
+there";
(my $re=$_)=~s/((\()|(\))|.)/${[')','']}[!$3]\Q$1\E${['(','']}[!$2]/gs
+;
$re= join'|',map{quotemeta}eval{/$re/};
die $@ if $@ =~ /unmatched/;
while( /((?:$re|[^,])*)/g ){
    print "$1\n";
}

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