This module implements the XML Schema list type. use XML::Schema::Type; # an object to represent the base type my $float = XML::Schema::Type::float->new(); # create a list type of the base type my $list = XML::Schema::Type::List->new( itemType => $float ); # instantiate a validated list my $items = $list->instance('3.14 2.718'); # add constraints to list $list->constrain( maxLength => 4 ); # max 3 items $item = $list->instance('1.2 3.4 5.6'); # OK $item = $list->instance('1.2 3.4 5.6 7.8'); # not OK - 4 items $item = $list->instance('hello'); # not OK - not a float