Function AST_PreparePathCreation

src/ast/ast_build_op_contexts.c:234–271

}

void AST_PreparePathCreation
(
	const cypher_astnode_t *path,
	const QueryGraph *qg,
	rax *bound_vars,
	NodeCreateCtx **nodes,
	EdgeCreateCtx **edges
) {
	GraphContext *gc = QueryCtx_GetGraphCtx();

	QueryGraph *g = QueryGraph_ExtractPaths(qg, &path, 1);
	uint path_elem_count = cypher_ast_pattern_path_nelements(path);
	for(uint i = 0; i < path_elem_count; i ++) {
		/* See if current entity needs to be created:
		 * 1. Current entity is NOT bound in a previous clause.
		 * 2. We have yet to account for this entity. */
		const cypher_astnode_t *elem = cypher_ast_pattern_path_get_element(path, i);
		const char *alias = AST_ToString(elem);

		// Skip entities defined in previous clauses or already represented in our nodes/edges arrays.
		int rc = raxTryInsert(bound_vars, (unsigned char *)alias, strlen(alias), NULL, NULL);
		if(rc == 0) continue;

		if((i % 2) == 1) {
			// relation
			QGEdge *e = QueryGraph_GetEdgeByAlias(g, alias);
			EdgeCreateCtx new_edge = _NewEdgeCreateCtx(gc, e, elem);
			array_append(*edges, new_edge);
		} else {
			// node
			QGNode *n = QueryGraph_GetNodeByAlias(g, alias);
			NodeCreateCtx new_node = _NewNodeCreateCtx(gc, n, elem);
			array_append(*nodes, new_node);
		}
	}

	QueryGraph_Free(g);
}

//------------------------------------------------------------------------------
// SORT operation