HashSet
The underlying collection type with unknown element type
The underlying collection type with unknown element type
A branch node of the HashTrieSet with at least one and up to 32 children.
A branch node of the HashTrieSet with at least one and up to 32 children.
the type of the elements contained in this hash set.
How levels work:
When looking up or adding elements, the part of the hashcode that is used to address the children array depends on how deep we are in the tree. This is accomplished by having a level parameter in all internal methods that starts at 0 and increases by 5 (32 = 2^5) every time we go deeper into the tree.
hashcode (binary): 00000000000000000000000000000000 level=0 (depth=0) level=5 (depth=1) level=10 (depth=2) ^^^^^ ...
Be careful: a non-toplevel HashTrieSet is not a self-contained set, so e.g. calling contains on it will not work! It relies on its depth in the Trie for which part of a hash to use to address the children, but this information (the level) is not stored due to storage efficiency reasons but has to be passed explicitly!
How bitmap and elems correspond:
A naive implementation of a HashTrieSet would always have an array of size 32 for children and leave the unused children empty (null). But that would be very wasteful regarding memory. Instead, only non-empty children are stored in elems, and the bitmap is used to encode which elem corresponds to which child bucket. The lowest 1 bit corresponds to the first element, the second-lowest to the second, etc.
bitmap (binary): 00010000000000000000100000000000 elems: [a,b] children: ---b----------------a-----------
Creates a collection with the specified elements.
Creates a collection with the specified elements.
the type of the collection's elements
the elements of the created collection
a new collection with elements elems
The standard CanBuildFrom instance for immutable.HashSet
An empty collection of type Set[A]
An empty collection of type Set[A]
the type of the set's elements
The default builder for Set
The default builder for Set
the type of the set's elements
The standard CanBuildFrom instance for Set
The standard CanBuildFrom instance for Set
This object provides a set of operations needed to create
immutable.HashSet