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The Pattern Interface The Pattern interface represents a basic unit of data in
JSOMap. Traditionally, a pattern is
a numerical vector, like
Figure 1.
UML diagram for the Pattern interface. To be totally flexible, JSOMap uses an abstract concept of
a pattern, represented by the Pattern interface.
An implementation of Pattern is some specific type of pattern.
For instance, DoublePattern could store a double[], IntPattern could
store an int[], and any other implementation could store any other type of data
unit. For example, GraphPattern
could store some concept of a graph, and could be used in graph matching. Since Pattern represents an abstract pattern, it cannot
specify any type-specific methods, like public double[] getPattern().
Instead, Pattern simply serves as the root interface for any data unit in
JSOMap. Implementations of Pattern should generally be immutable value classes. This means that once an instance is created it cannot be changed in any way. To be immutable, a class must
By being immutable, you’re guaranteed that the class is
never going to change. However,
this isn’t a strict guideline; immutable classes may be necessary in some
cases, like when it’s very expensive to create a new instance. Implementations of Pattern should generally provide two constructors:
The value constructor specifies arguments that can be used
to create the Pattern instance. The
string constructor accepts a string representation of the pattern.
Providing the value constructor is commonsense.
Providing the String constructor is an easy way to create patterns from a
text data file. The JSOMap package comes with two implementations of
Pattern: DoublePattern and IntegerPattern.
These are basic vector-based implementations that store the actual data
in arrays of type double and int, respectively.
Figure 2.
UML diagram for the DoublePattern and IntegerPattern classes.
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