my $filter = ".filter(function(idx) { return this.substr(0, " . length($params{with}) . ") == '$params{with}'; })";
$filter .= ".map(function(idx, str) { return str.replace('$params{with}_', ''); })";
my $filter = ".filter(function(idx) { return this.substr(0, " . length($params{with}) . ") == '$params{with}'; })";
$filter .= ".map(function(idx, str) { return str.replace('$params{with}_', ''); })";