Module alphabet 
Source - BitSet π 
 - The representation of a byte set. Split out so that we can define a
convenient Debug impl for it while keeping βByteSetβ in the output.
 - ByteClassElementRanges π 
 - An iterator over all elements in an equivalence class expressed as a
sequence of contiguous ranges.
 - ByteClassElements π 
 - An iterator over all elements in a specific equivalence class.
 - ByteClassIter π 
 - An iterator over each equivalence class.
 - ByteClassSet π 
 - A partitioning of bytes into equivalence classes.
 - ByteClasses π 
 - A representation of byte oriented equivalence classes.
 - ByteSet π 
 - A simple set of bytes that is reasonably cheap to copy and allocation free.