Parse tree pattern matcher
We have a small domain-specific language that we use to define patterns to look for in tree-sitter parse trees. This DSL enables us to rapidly define new syntactic scope types and support new programming languages.
Format
GRAND_PARENT_TYPE.*.CHILD_TYPE[FIELD]!?
| Syntax | Description |
|---|---|
| TYPE | Match node typenode.type |
Dot operator(.) | Type hierarchy between parent and child |
Wildcard op(*) | Match any type |
Negation op(~) | Match any type other than what is specified after ~ |
Important op(!) | Use this node as result instead of parent. By default the leftmost/top node is used |
Optional op(?) | Node is optional. Will match if available. |
Field op([field]) | Return child node at given field.node.childForFieldName(field) |
Index op([n]) | Return nth named child node. |
Multiple patterns
When using multiple patterns evaluation will be performed top to bottom and the first pattern too match will be used.
["export_statement?.class_declaration", "export_statement.class"];