Modifying selections with path patterns

[Screwtapello]

Raw Kakoune has commands to add and move selections through the file's linear structure, like h and C and ]p.

kak-tree has commands to add and move selections through the file's hierarchical structure, like tree-select-node and tree-select-prev-node and tree-select-children.

Raw Kakoune also has commands to sub-select and filter selections based on the file's linear structure, like s and k.

kak-tree should have commands to sub-select and filter selections based on the file's hierarchical structure:

• tree-select-nodes KIND selects all the KIND nodes wholly contained within an existing selection
• tree-split-nodes KIND slices the KIND nodes out of existing selections
  • not so useful in a hierarchical context, but for completeness and by analogy with Kakoune's core operators
• tree-keep-matching KIND discards selections that do not wholly contain at least one KIND node
• tree-kill-matching KIND discards selections that do wholly contain at least one KIND node

Ideally, these commands should use -shell-script-candidates to let Kakoune auto-complete the possible kinds for the current file.

There's possible extension here for kind-paths, like arguments/string_literal to only select string_literals directly inside an arguments or /arguments//string_literal to select string_literals anywhere inside whichever selections exactly cover an arguments, but that's all polish and future extension work.

[ul]

Just to track progress: tree-select-nodes KIND is done by tree-select-children which takes an optional parameter KIND. Other commands are not implemented yet.