How do I parse a string containing nested functions with parameters, e.g. 
Example 1:  A(B(2))
Example 2:  A(B(2)+C(D()))

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I need to find matching pairs of parenthesis and call a sub that expands each function. My first attempt was to use recursion and a regex with greedy search. This works for example 1, but fails for example 2 because the regex does not find the matching parenthesis: 
#!/usr/bin/perl -wT

# example 1
my $text = "A(B(2))";
$text = doFunc( "MAIN", $text );
print "Example 1: $text\n";

# example 2
$text = "A(B(2)+C(D()))";
$text = doFunc( "MAIN", $text );  # this fails!
print "Example 2: $text\n";

sub doFunc
{
  my( $theFunc, $theParam ) = @_;

  # FIXME: greedy match fails with: 'TT(TT()+TT(TT()))'
  $theParam =~ s/([A-Z]+)\((.*)\)/&doFunc($1,$2)/geo;

  my $result = "";

  if( $theFunc eq "MAIN" ) {
    $result = $theParam;

  } else {
    # dummy switch here for demonstration
    # this would be an elsif for each function
    $result = "func $theFunc returns <$theParam>";

  }

  return $result;
}

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Any help is greatly appreciated. Thanks!

In reply to How to find matching pairs by Anonymous Monk

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