 PRIVATE>
 
 <<
+
 SYNTAX: ROMAN-OP:
     scan-word [ name>> "roman" prepend create-in ] keep
     1quotation '[ _ binary-roman-op ]
     dup infer [ in>> ] [ out>> ] bi
     [ "string" <repetition> ] bi@ <effect> define-declared ;
+
 >>
 
 ROMAN-OP: +

PRIVATE>

: >roman ( n -- str )
    dup roman-range-check [ (>roman) ] "" make ;

: >ROMAN ( n -- str ) >roman >upper ;

: roman> ( str -- n )
    >lower [ roman<= ] monotonic-split [ (roman>) ] sigma ;

<PRIVATE



ERROR: roman-range-error n ;

: roman-range-check ( n -- n )
    dup 1 3999 between? [ roman-range-error ] unless ;

: roman-digit-index ( ch -- n )
    1string roman-digits index ; inline

: roman>= ( ch1 ch2 -- ? )
    [ roman-digit-index ] bi@ >= ;

: roman>n ( ch -- n )
    roman-digit-index roman-values nth ;

: (roman>) ( seq -- n )
    [ [ roman>n ] map ] [ all-eq? ] bi
