Module Ppxlib.Ast_traverseSource

This module provides AST traversal classes, such as maps, iterations, folds, etc. on the Parsetree types.

Link to the tutorial

For a detailed explanation on this module, refer to the relevant part of the manual.

API

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