4.11.1 About Filter Expressions

Filter expressions are expressions that are evaluated for each vertex or edge. The expression can define predicates that a vertex or an edge must fulfil in order to be contained in the result, in this case a subgraph.

Consider an example graph that consists of four vertices (nodes) and four edges. For an edge to match the filter expression src.prop == 10, the source vertex prop property must equal 10. Two edges match that filter expression, as shown in the following figure.

Figure 4-5 Edges Matching src.prop == 10

Description of "Figure 4-5 Edges Matching src.prop == 10"

The following figure shows the graph that results when the filter is applied.

Figure 4-6 Graph Created by the Simple Filter

Description of "Figure 4-6 Graph Created by the Simple Filter"

The vertex filter src.prop == 10 filters out the edges associated with vertex 333 and the vertex itself.