use HOP::Lexer 'string_lexer';
my $text = 'xselectx';
my $lexer = string_lexer( $text,
  [KEYWORD  => qr/select/i],
  [WORD     => qr/\w+/    ]
);

##</code><code>##

['WORD','x'],
['KEYWORD','select'],
['WORD','x']

##</code><code>##

use HOP::Lexer 'string_lexer';
my $text = 'select xselectx';
my $lexer = string_lexer( $text,
  [WORD     => qr/\w+/    ],
  [KEYWORD  => qr/select/i],
);

##</code><code>##

['WORD','select'],
' ',
['WORD','xselectx']