my $checks = [
  {
   test => sub {
     my $state = shift;
     my $tok = shift;
     if ($state->{checkPrefix}) {
       return $state->{base} = &driveBase($canon{$tok}, {%$Args, check
+Prefix=>0}));
     }
     return;
   },
   action => sub {
     my $state = shift;
     my $tok   = shift;
     &equivWord($tok, $cannon{$tok}, {});
   },
  },

  # Check number 2
  {
   test => sub { ... },
   action => sub { ... },
  },

  # and so on

  # Make your last test succeed (test => sub {1}),
  # and have your default logic go there.
];

while (my $tok = getTok(...)) {
  resetState($state);
  foreach my $check (@$checks) {
    if ($check->test($state, $tok)) {
      $check->action($state, $tok);
      last;
    }
  }
}
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