use GraphQL::Schema;
my $FH;
open($FH, '<:utf8', 'schema.sdl') or die "failed to open SDL file, $!";
my $SDLcontent;
{ local $/ = undef; $SDLcontent = <$FH>; } close $FH;

my $schema = GraphQL::Schema->from_doc($SDLcontent);
if( ! defined $schema ){ die "failed to parse SDL schema." }