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Weston Pace commented on ARROW-18265: ------------------------------------- Ok. I think I understand now. The problem isn't how the user expresses it but more how we construct a FieldPath / FieldRef for one of these pseudo-refs. I don't think we rely on the child referencing behavior for variable length lists anywhere today so it's probably ok in that sense. However, it would be a bit tricky if FindOne/FindAll ended up calling list_element (a compute function). FindOne/FindAll currently is in the core module and not the compute module. That being said we don't really distinguish between the two and I think have all but accepted they are co-mingled. > [C++] Allow FieldPath to work with ListElement > ---------------------------------------------- > > Key: ARROW-18265 > URL: https://issues.apache.org/jira/browse/ARROW-18265 > Project: Apache Arrow > Issue Type: Improvement > Components: C++ > Reporter: Miles Granger > Assignee: Miles Granger > Priority: Major > Labels: pull-request-available > Fix For: 11.0.0 > > Time Spent: 1h 40m > Remaining Estimate: 0h > > {{FieldRef::FromDotPath}} can parse a single list element field. ie. > {{{}'path.to.list[0]`{}}}but does not work in practice. Failing with: > _struct_field: cannot subscript field of type list<....>_ > Being able to add a slice or multiple list elements is not within the scope > of this issue. -- This message was sent by Atlassian Jira (v8.20.10#820010)