 SINGLETONS: beginning-of-input ^ end-of-input $ end-of-file
 ^unix $unix word-break ;
 
-TUPLE: range-class from to ;
+TUPLE: range-class { from read-only } { to read-only } ;
 C: <range-class> range-class
 
-TUPLE: primitive-class class ;
+TUPLE: primitive-class { class read-only } ;
 C: <primitive-class> primitive-class
 
-TUPLE: category-class category ;
+TUPLE: category-class { category read-only } ;
 C: <category-class> category-class
 
-TUPLE: category-range-class category ;
+TUPLE: category-range-class { category read-only } ;
 C: <category-range-class> category-range-class
 
-TUPLE: script-class script ;
+TUPLE: script-class { script read-only } ;
 C: <script-class> script-class
 
 GENERIC: class-member? ( obj class -- ? )

M: category-range-class class-member? inline
    [ category first ] [ category>> ] same? ; inline

TUPLE: not-class class ;

PREDICATE: not-integer < not-class class>> integer? ;


    seq length {
        { 0 [ empty ] }
        { 1 [ seq first ] }
        [ drop seq { } like class boa ]
    } case ; inline

TUPLE: class-partition integers not-integers simples not-simples and or other ;
