Ast_bs_open (melange.Melange_ppx_lib.Ast_bs

let convertBsErrorFunction: 
  Melange_compiler_libs.Location.t =>
  Melange_compiler_libs.Ast_mapper.mapper =>
  Melange_compiler_libs.Ast_helper.attrs =>
  list(Melange_compiler_libs.Parsetree.case) =>
  Melange_compiler_libs.Parsetree.expression;