Because MapSet operations benefit greatly from memoization, maintaining a set of interned sets benefits performance. After calling clearCache, call this method to re-register extant live instances to the instance cache.
Return all unique values occurring for a given dimension. Unless this is the empty set, the return value is always non-empty. If dim doesn't occur, it will be [nullValue].
Refactor this matrix into one with the same data, but putting the given dimension in front. This will speed up access to values with the given dimension. If the dimension does not yet occur in the set (or any subset), it is instantiated with a single nullValue value. The set must be non-empty.
Return a set which represents the Cartesian product between this set and the given values across the specified dimension.
Return a set which represents the Cartesian product between this and the given set. Duplicate dimensions are first removed from this set. For best performance, call big.cartesianProduct(small)
Return the total number of items in this set.
Intern and deduplicate this MapSet. Needs to be called only after constructing a MapSet manually (by allocating, populating, and setting root).
Return a subset of this set for all points where the given dimension has this value. Unlike slice, the dimension itself is included in the result (with the given value).
Collect the names of all dimensions occurring in this tree.
Return all values for all dimensions occurring in this set. The Cartesian product of these values would thus be a superset of this set. This is equivalent to, but faster than, calling getDims and then all for each dim.
Combine two matrices together, returning their union. If other is a subset of this, return this unchanged.
Refactor this matrix into one with the same data, but attempting to lower the total number of nodes.
"Unset" a given dimension, removing it from the matrix. The result is the union of all sub-matrices for all values of dim.
Set the given dimension to always have the given value, collapsing (returning the union of) all sub-matrices for previously different values of dim.
Return a sub-matrix for all points where the given dimension has this value. The dimension itself is not included in the result. Note: if dim doesn't occur (e.g. because this is the unit set) and value is nullValue, this returns the unit set (not the empty set).
Return the difference between this and the given set. If other does not intersect with this, return this unchanged.
Count and return the total number of unique nodes in this MapSet.
Clear the global operations cache. Because subtrees can be reused within the tree, a way of memoizing operations across the entire tree (instead of just across children of a single node, or siblings) is crucial for performance. Call this function to clear this cache.
The empty set. Represents a set which holds zero values.
A set containing a single nil-dimensional element. Holds exactly one value (a point with all dimensions at nullValue).
If emptySetRoot, zero values. If null, one value with zero dimensions. Otherwise, pointer to node describing the next dimension.
The type used to indicate the name (or index) of a dimension.
The type for indicating a point on a dimension's axis.
A value for DimValue indicating that a dimension is unset
Data structure for holding optimized "sparse" N-dimensional matrices. The number of dimensions is arbitrary and can be varied at runtime.
Unlike classical sparse arrays/matrices, this data structure is optimized not just for arrays which are mostly zero (or any given value), but for any matrices where data is likely to repeat across dimensions.
This is done by storing the data as a tree, with each depth representing one dimension. A sub-tree is, thus, a sub-matrix (slice of the matrix represented by the top-level tree) along the top-level dimension. Each sub-tree is individually immutable, and can therefore be shared within the same tree or even by several instances of this type.
Dimension order need not be the same for all sub-trees. Even the number of dimensions in siblings' sub-trees need not be the same; i.e, the data structure is itself sparse with regards to the dimensions.
As there is no explicit "value" type (associated with every set of coordinates), this data structure can be seen as a representation of a set of points, but it can be simulated by adding a "value" dimension (in the same way how a gray-scale image can be represented as a set of 3D points like a height-map).
An alternative way to look at this data structure is as a set of maps (i.e. associative arrays). Thus, each layer of the tree stores one possible map key, and under it, all the maps that have this key with a specific value. Note that for this use case, DimValue needs to have a value (configured using nullValue) which indicates the absence of a certain key (dimension) in a map.