use strict;
my $sql = <<'--SQL--';
aaaa a baaaab a
--SQL--

use HOP::Lexer 'make_lexer';
my @sql   = $sql;
my $lexer = make_lexer(
    sub { shift @sql },  # iterator
    [ A      => qr/a+/i         ],
    [ BAB    => qr/ba+b/i       ],
    [ SPACE  => qr/\s+/, sub {} ],
);