add base & pack

pack.go

@@ -0,0 +1,29 @@
+package unibase2n
+
+import "unsafe"
+
+type Pack uint64
+
+var (
+	Base16384 = newbasepack(0x4e00, 0x3d00, 14)
+	Base8192  = newbasepack(0xac00, 0xcc00, 13)
+	Base256   = newbasepack(0x1100, 0x0000, 4)
+)
+
+func newbasepack(off, til uint16, bit uint8) Pack {
+	b, err := NewBase(off, til, bit)
+	if err != nil {
+		panic(err)
+	}
+	return b.Pack()
+}
+
+func New(pack Pack) *Base {
+	b := &Base{}
+	*(*Pack)(unsafe.Pointer(b)) = pack
+	return b
+}
+
+func (b *Base) Pack() Pack {
+	return *(*Pack)(unsafe.Pointer(b))
+}