Repository: tinkerpop Updated Branches: refs/heads/master fcabd01c4 -> df928cde0
Add self loop example to Cycle Detection recipe. Project: http://git-wip-us.apache.org/repos/asf/tinkerpop/repo Commit: http://git-wip-us.apache.org/repos/asf/tinkerpop/commit/3afc5765 Tree: http://git-wip-us.apache.org/repos/asf/tinkerpop/tree/3afc5765 Diff: http://git-wip-us.apache.org/repos/asf/tinkerpop/diff/3afc5765 Branch: refs/heads/master Commit: 3afc57653a9ca81ba560b1b9a6be8c3ad7b1251d Parents: 47e0600 Author: Kevin Gallardo <kevin.galla...@datastax.com> Authored: Fri Aug 24 17:18:43 2018 -0400 Committer: Kevin Gallardo <kevin.galla...@datastax.com> Committed: Fri Aug 31 15:35:22 2018 -0400 ---------------------------------------------------------------------- docs/src/recipes/cycle-detection.asciidoc | 33 +++++++++++++++++++++++--- 1 file changed, 30 insertions(+), 3 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/tinkerpop/blob/3afc5765/docs/src/recipes/cycle-detection.asciidoc ---------------------------------------------------------------------- diff --git a/docs/src/recipes/cycle-detection.asciidoc b/docs/src/recipes/cycle-detection.asciidoc index 57adc6e..1e25740 100644 --- a/docs/src/recipes/cycle-detection.asciidoc +++ b/docs/src/recipes/cycle-detection.asciidoc @@ -48,9 +48,36 @@ the length of the cycle is known to be three and there is no need to exceed that cycle. It returned three, because there was one for each vertex that started the cycle (i.e. one for `A`, one for `B` and one for `C`). This next line introduce deduplication to only return unique cycles. -The above case assumed that the need was to only detect cycles over a path length of three. It also respected the -directionality of the edges by only considering outgoing ones. What would need to change to detect cycles of -arbitrary length over both incoming and outgoing edges in the modern graph? +The above case assumed that the need was to only detect cycles over a path length of three. +It also respected the directionality of the edges by only considering outgoing ones. + +Also note that the traversal above won't detect self-loops (vertices directly connected to +themselves). To do so, you would need to `.emit()` a Traverser before the repeat()-loop. + +[gremlin-groovy] +---- +g.addV().property(id,'a').as('a'). + addV().property(id,'b').as('b'). + addV().property(id,'c').as('c'). + addV().property(id,'d').as('d'). + addE('knows').from('a').to('b'). + addE('knows').from('b').to('c'). + addE('knows').from('c').to('a'). + addE('knows').from('a').to('d'). + addE('knows').from('c').to('d'). + addE('self').from('a').to('a').iterate() +g.V().as('a'). + emit(). + repeat(outE().inV().simplePath()). + times(2). + outE().inV().where(eq('a')). + path(). + by(id). + by(label) +---- + +What would need to change to detect cycles of arbitrary length over both incoming and +outgoing edges, in the modern graph? [gremlin-groovy,modern] ----
