Uni.pm6

my class NFC is repr('VMArray') is array_type(uint32) { ... }
my class NFD is repr('VMArray') is array_type(uint32) { ... }
my class NFKC is repr('VMArray') is array_type(uint32) { ... }
my class NFKD is repr('VMArray') is array_type(uint32) { ... }

my class Uni does Positional[uint32] does Stringy is repr('VMArray') is array_type(uint32) {
    method new(*@codes) {
        my $uni := nqp::create(self);
        my int $n = @codes.elems;
        loop (my int $i = 0; $i < $n; $i = $i + 1) {
            nqp::bindpos_i($uni, $i, @codes.AT-POS($i));
        }
        $uni
    }

    my class UniList does Iterator {
        has $!uni;
        has int $!els;
        has int $!i;
        method !SET-SELF(\uni) {
            $!uni := uni;
            $!i    = -1;
            $!els  = nqp::elems(uni);
            self
        }
        method new (\uni) { nqp::create(self)!SET-SELF: uni }
        method pull-one {
            nqp::if(
              nqp::islt_i(($!i = nqp::add_i($!i, 1)), $!els),
              nqp::atpos_i($!uni, $!i),
              IterationEnd)
        }
        method push-all($target --> IterationEnd) {
            nqp::stmts(
              (my     $uni := $!uni), # lexicals faster than attrs
              (my int $els  = $!els),
              (my int $i    = $!i),
              nqp::while(
                nqp::islt_i(($i = nqp::add_i($i, 1)), $els),
                $target.push: nqp::atpos_i($uni, $i)),
              ($!i = $i))
        }
        method count-only {
            nqp::p6box_i(
              nqp::if(
                nqp::islt_i($!i, nqp::elems($!uni)),
                nqp::sub_i(nqp::elems($!uni), nqp::add_i($!i, 1)),
                0))
        }
        method bool-only { nqp::p6bool(self.count-only) }
    }
    method list(Uni:D:) { Seq.new(UniList.new(self)) }

    method Uni(Uni:D:) {
        self
    }

    method NFC(Uni:D:) {
        nqp::normalizecodes(self, nqp::const::NORMALIZE_NFC, nqp::create(NFC))
    }

    method NFD(Uni:D:) {
        nqp::normalizecodes(self, nqp::const::NORMALIZE_NFD, nqp::create(NFD))
    }

    method NFKC(Uni:D:) {
        nqp::normalizecodes(self, nqp::const::NORMALIZE_NFKC, nqp::create(NFKC))
    }

    method NFKD(Uni:D:) {
        nqp::normalizecodes(self, nqp::const::NORMALIZE_NFKD, nqp::create(NFKD))
    }

    multi method Str(Uni:D:) {
        nqp::strfromcodes(self)
    }

    multi method Bool(Uni:D:) {
        nqp::p6bool(nqp::elems(self));
    }

    method codes(Uni:D:)   { nqp::elems(self) }
    method elems(Uni:D:)   { nqp::elems(self) }
    method Numeric(Uni:D:) { nqp::elems(self) }
    method Int(Uni:D:)     { nqp::elems(self) }

    multi method EXISTS-POS(Uni:D: int \pos) {
        nqp::p6bool(
          nqp::islt_i(pos,nqp::elems(self)) && nqp::isge_i(pos,0)
        );
    }
    multi method EXISTS-POS(Uni:D: Int:D \pos) {
        pos < nqp::elems(self) && pos >= 0;
    }

    multi method AT-POS(Uni:D: int \pos) {
        nqp::isge_i(pos,nqp::elems(self)) || nqp::islt_i(pos,0)
          ?? Failure.new(X::OutOfRange.new(
               :what($*INDEX // 'Index'),
               :got(pos),
               :range("0..{nqp::elems(self)-1}")))
          !! nqp::atpos_i(self, pos)
    }
    multi method AT-POS(Uni:D: Int:D \pos) {
        my int $pos = nqp::unbox_i(pos);
        nqp::isge_i($pos,nqp::elems(self)) || nqp::islt_i($pos,0)
          ?? Failure.new(X::OutOfRange.new(
               :what($*INDEX // 'Index'),
               :got(pos),
               :range("0..{nqp::elems(self)-1}")))
          !! nqp::atpos_i(self,$pos)
    }

    multi method gist(Uni:D:) {
        self.^name ~ ':0x<' ~ self.list.fmt('%04x', ' ') ~ '>'
    }

    multi method perl(Uni:D:) {
        'Uni.new(' ~ self.list.fmt('0x%04x', ', ') ~ ')' ~
            (self.WHAT === Uni ?? '' !! '.' ~ self.^name);
    }
}

my class NFD is Uni {
    method new(|) {
        die "Cannot create an NFD directly"; # XXX typed, better message
    }

    method NFD() { self }
}

my class NFC is Uni {
    method new(|) {
        die "Cannot create an NFC directly"; # XXX typed, better message
    }

    method NFC() { self }
}

my class NFKD is Uni {
    method new(|) {
        die "Cannot create an NFKD directly"; # XXX typed, better message
    }

    method NFKD() { self }
}

my class NFKC is Uni {
    method NFKC() { self }

    method new(|) {
        die "Cannot create an NFKC directly"; # XXX typed, better message
    }
}

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