15.2.1.1.2 Session-Bound Collections

You can create and manipulate collections directly in the session without the need for a graph. Session-bound collections can be further passed as parameters to graph algorithms or used like any other collection object. The following sub-sections describe the currently supported types for these collections.

Scalar Collections

Scalar collections contain simple data types like Integer, Long, Float, Double and Boolean. They can be managed by the PgxSession APIs:

Creation of a Scalar Collection

You can use createSet() and createSequence() methods to create a scalar collection as shown in the following code:

Creating a Scalar Collection Using JShell

myIntSet = session.createSet(PropertyType.INTEGER, "myIntSet")
myDoubleSequence = session.createSequence(PropertyType.DOUBLE)  // A name will be automatically generated if none is provided.
println myDoubleSequence.getName()                              // Display the generated name.

Creating a Scalar Collection Using Java

import oracle.pgx.api.*;
import oracle.pgx.common.types.*;
...
ScalarSet myIntSet = session.createSet(PropertyType.INTEGER, "myIntSet");
ScalarSequence myDoubleSequence = session.createSequence(PropertyType.DOUBLE);
System.out.println(myDoubleSequence.getName());

Run Operations on a Scalar Collection

You can run several operations on a scalar collection as shown in the following code:

Running Operations on a Scalar Collection Using JShell

myIntSet.add(10)
myIntSet.addAll([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
myIntSet.addAll([0,1,2])                // Element uniqueness. This operation has no effect on the set.
println myIntSet

myIntSet.contains(1)                   // Checks the presence of an element. This code returns `true`.
myIntSet.remove(10)
myIntSet.removeAll([4, 5, 6, 7, 8, 9]) // Leaves only elements `0, 1, 2, 3`.
println  myIntSet

Running Operations on a Scalar Collection Using Java

import java.util.Arrays;
import oracle.pgx.api.*;
...
myIntSet.add(10);
myIntSet.addAll(Arrays.asList(0, 1, 2, 3, 4, 5, 6, 7, 8, 9));
myIntSet.addAll(Arrays.asList(0, 1, 2))

myIntSet.contains(1);  // Returns `true`.
myIntSet.remove(10);
myIntSet.removeAll(Arrays.asList(4, 5, 6, 7, 8, 9));

Traversal of a Scalar Collection

You can traverse a scalar collection either using an iterator or using the new Stream API. You can add elements of a sequence to a set, traverse a sequence and filter out elements not required, and then add the rest to another scalar collection.

Traversing a Scalar Collection Using JShell

myIntSet.forEach({x -> print x + "\n"})
myIntSet.stream().filter({x -> x % 2 == 0}).forEach({x -> myDoubleSequence.add(x)})
println myDoubleSequence

Traversing a Scalar Collection Using Java

import java.util.Iterator;
import java.util.stream.Stream;
import oracle.pgx.api.*;
...
myIntSet.forEach(x -> System.out.println(x))
myIntSet.stream().filter(x -> x % 2 == 0).forEach(myDoubleSequence::add)