Adding textobject queries

Helix supports textobjects that are language specific, such as functions, classes, etc. These textobjects require an accompanying tree-sitter grammar and a textobjects.scm query file to work properly. Tree-sitter allows us to query the source code syntax tree and capture specific parts of it. The queries are written in a lisp dialect. More information on how to write queries can be found in the official tree-sitter documentation.

Query files should be placed in runtime/queries/{language}/textobjects.scm when contributing to Helix. Note that to test the query files locally you should put them under your local runtime directory (~/.config/helix/runtime on Linux for example).

The following captures are recognized:

Capture Name

Example query files can be found in the helix GitHub repository.

Queries for textobject based navigation

Tree-sitter based navigation in Helix is done using captures in the following order:

  • object.movement
  • object.around
  • object.inside

For example if a function.around capture has been already defined for a language in its textobjects.scm file, function navigation should also work automatically. function.movement should be defined only if the node captured by function.around doesn't make sense in a navigation context.