tree-sitter query api notes

tree-sitter-api-notes.md

• current docs
  • query consists of one or more patterns
  • each pattern is an s-expression that matches nodes in a tree
  • expression consists of pair of parens containing:
    • node's type
    • optionally series of other s-expressions matching node's children
  • prefix a child pattern with a field name followed by a colon
  • match anonymous nodes by expressing name between double quotes
  • captures enable association of names with specific nodes in a pattern
    • capture names are written after the nodes they refer to
    • capture names start with the @ character
  • quantification operators can be used to match a repeating sequence of sibling nodes
    • postfix + -> one or more repetitions
    • postfix * -> zero or more repetitions
    • postifx ? -> zero or one repetition
  • grouping sibling nodes
    • sequence of sibling nodes can be grouped via parentheses
    • any of the quantification operators (+, *, ?) can be applied to groups
  • alternations expressed by listing patterns between []
  • wildcard node matches any node and expressed by _
  • anchor operator . is used to constrain ways in which child patterns are matched
    • before first child in a pattern, child only matches if it's the first named node
    • after first child in pattern, child only matches if it's the last named node
    • between child patterns, child only matches that are immediate siblings
  • predicate s-expressions (e.g. #match?, #eq?, etc.)
• 2020-02-20
  • anchor operator
• 2020-05-12
  • wildcards with _
  • repetition with *
  • grouping with ()
  • predicates with #
• 2020-05-30
  • alternations
• 2020-09-22
  • match on supertypes
• 2020-10
  • consecutive siblings
• 2020-10
  • metadata block with subsequent curly braces