# Pastebin uJ3iB2XB
MacBook-Pro-de-Fernando:Red2 fernando$ perl6 -MRed -e 'model M is table<mmm> { has Str $.a is column; has Str $.b is column{ :nullable }}; dd M.a ~ M.b'
Red::AST::Concat.new(op => "~", returns => Bool, left => Red::AST::Cast.new(type => "str", value => Red::Column.new(attr => mmm.a, attr-name => "a", id => Bool::False, auto-increment => Bool::False, references => Callable, nullable => Bool::False, name => "a", class => M, name-alias => "a", type => Str, inflate => { ... }, deflate => { ... }, computation => Any)), right => Red::AST::Cast.new(type => "str", value => Red::Column.new(attr => mmm.b, attr-name => "b", id => Bool::False, auto-increment => Bool::False, references => Callable, nullable => Bool::True, name => "b", class => M, name-alias => "b", type => Str, inflate => { ... }, deflate => { ... }, computation => Any)), bind-left => Bool::False, bind-right => Bool::False)
MacBook-Pro-de-Fernando:Red2 fernando$ perl6 -MRed -e 'model M is table<mmm> { has Str $.a is column; has Str $.b is column{ :nullable }}; dd "{M.a}{M.b}"'
"Red::Column<140284827150464>Red::Column<140284827150608>"