Function _QueryGraph_ExtractPath

src/graph/query_graph.c:204–241

clones path from 'qg' into 'graph'

// clones path from 'qg' into 'graph'
static void _QueryGraph_ExtractPath
(
	const QueryGraph *qg,
	QueryGraph *graph,
	const cypher_astnode_t *path
) {

	// validate input
	ASSERT(qg != NULL && graph != NULL && path != NULL);

	const char *alias;
	const cypher_astnode_t *ast_node;
	uint nelems = cypher_ast_pattern_path_nelements(path);

	// introduce nodes to graph
	// nodes are at even indices
	for(uint i = 0; i < nelems; i += 2) {
		ast_node = cypher_ast_pattern_path_get_element(path, i);
		_QueryGraph_ExtractNode(qg, graph, ast_node);
	}

	// introduce edges to graph
	// edges are at odd indices
	for(uint i = 1; i < nelems; i += 2) {
		// retrieve the QGNode corresponding to the node left of this edge
		const cypher_astnode_t *l_node = cypher_ast_pattern_path_get_element(path, i - 1);
		const char *l_alias = AST_ToString(l_node);
		QGNode *left = QueryGraph_GetNodeByAlias(graph, l_alias);

		// retrieve the QGNode corresponding to the node right of this edge
		const cypher_astnode_t *r_node = cypher_ast_pattern_path_get_element(path, i + 1);
		const char *r_alias = AST_ToString(r_node);
		QGNode *right = QueryGraph_GetNodeByAlias(graph, r_alias);

		ast_node = cypher_ast_pattern_path_get_element(path, i);
		_QueryGraph_ExtractEdge(qg, graph, left, right, ast_node);
	}
}

QueryGraph *QueryGraph_New
(