https://dokuwiki.grogra.de/ 2026-05-16T10:32:42+00:00 https://dokuwiki.grogra.de/ https://dokuwiki.grogra.de/lib/exe/fetch.php?media=wiki:dokuwiki.svg text/html 2025-08-22T10:48:03+00:00 Anonymous (anonymous@undisclosed.example.com) https://dokuwiki.grogra.de/doku.php?id=01_user_documentation:07_rgg_xl:02_xl:03_query:01_predicate:01_node&rev=1755859683&do=diff Node pattern Node predicates represent patterns applied on the Nodes in the graph. They are the base of XL queries, as it is required to have at least one node predicate in a query. Type Query nodes from their type. E.g. the predicate Sphere within a query is a pattern that matches instances of Sphere. text/html 2025-08-22T11:40:59+00:00 Anonymous (anonymous@undisclosed.example.com) https://dokuwiki.grogra.de/doku.php?id=01_user_documentation:07_rgg_xl:02_xl:03_query:01_predicate:02_path&rev=1755862859&do=diff Path pattern Path patterns enable to add edge (or path more generally) predicates between node patterns. Implicit The XL language defines two implicit edge patterns, whitespace and brackets. These patterns bound two nodes such as: the left node is bound as source of the edge, and the right node is bound as target. The patterns then are defined as: text/html 2025-11-25T11:36:33+00:00 Anonymous (anonymous@undisclosed.example.com) https://dokuwiki.grogra.de/doku.php?id=01_user_documentation:07_rgg_xl:02_xl:03_query:01_predicate:03_transitive_closure&rev=1764070593&do=diff Transitive closure Transitive closures of relations follow the well-known syntax of regular expressions where patterns to be repeated are enclosed in parentheses with a quantifier appended. The possible quantifiers are: * + : 1-to-n repetitions. text/html 2025-08-25T09:34:32+00:00 Anonymous (anonymous@undisclosed.example.com) https://dokuwiki.grogra.de/doku.php?id=01_user_documentation:07_rgg_xl:02_xl:03_query:01_predicate:04_singlelate_match&rev=1756114472&do=diff Single, Late match Single, late and optional matches enables to restrict the set of matches to a specific condition. These conditions can improve the pattern matching in as it might enable to skip some of the predicates. The syntax is: * : : for single match text/html 2025-08-22T13:55:36+00:00 Anonymous (anonymous@undisclosed.example.com) https://dokuwiki.grogra.de/doku.php?id=01_user_documentation:07_rgg_xl:02_xl:03_query:01_predicate:10_conpound&rev=1755870936&do=diff Combining Node patterns, combined with path patterns, define a connected pattern graph. The pattern graph may additionally: * Combine several path patterns without node pattern. * Use unconnected part with the separator comma (,). * Include boolean valued expression as condition.