Abstract-Type and Scheme-Definition Language (ASDL) A language developed as part of project , as a basis for generating s and environments. It combines an type system, syntax-directed translation schemes and a target-language interface. ["ASDL - An Object-Oriented Specification Language for Syntax-Directed Environments", M.L. Christ-Neumann et al, European Software Eng Conf, Strasbourg, Sept 1987, pp.77-85]. (1996-02-19)