Ranking of open PRs

After a week away we have a bit of a backlog, and in such circumstances it seems best to get as many "easy" ones out of the way quickly. Here's my ranking:

2.1. PR #1137: 161 Variadic functions

Potentially difficult; it would be best to have some online feedback first

2.2. PR #1132: 122 Choice item types (generalizing local union types)

Hopefully easy

2.3. PR #1131: 796,231 - Extend XPath for and let expressions

Hopefully easy

2.4. PR #1125: 1094 Enhanced lookup expressions

Medium

2.5. PR #1120: 99v2 deep equal with callback

Hopefully easy as we've discussed the ideas in previous meeting

2.6. PR #1117: 1116 Add options param to unparsed-text

Medium

2.7. PR #1108: 566-partial Describe a less aggressive %-encoding for fn:build-uri

Hopefully easy

2.8. PR #1098: 566-partial Editorial improvements for parse-uri

Hopefully easy

2.9. PR #1093: 1091 Add fn:collation function

Hopefully easy

2.10. PR #1087: 1086 Editorial changes to array:values

Drop this for potential revision

2.11. PR #1068: 73 fn:graphemes

Medium

2.12. PR #1062/#1027: fn:ranks

See PR #1062 <https://qt4cg.org/dashboard/#pr-1062> See PR #1027 <https://qt4cg.org/dashboard/#pr-1027>
No progress since previous discussion of these proposals.