package ppxlib

AST traversal classes

To use these classes, inherit from them and override the methods corresponding to the types from Parsetree you want to process. For instance to collect all the string constants in a structure:

let string_constants_of =
  object
    inherit [string list] Ast_traverse.fold as super

    method! expression e acc =
      let acc = super#expression e acc in
      match e.pexp_desc with
      | Pexp_constant (Const_string (s, _)) -> s :: acc
      | _ -> acc

    method! pattern p acc =
      let acc = super#pattern p acc in
      match p.ppat_desc with
      | Ppat_constant (Const_string (s, _)) -> s :: acc
      | _ -> acc
  end

let string_constants_of_structure = string_constants_of#structure