2651	 The Treatment of Data Types in EL	 In constructing a general purpose programming language a key issue is providing a sufficient set of data types and associated operations in a manner that permits both natural problem-oriented notation and efficient implementation. The EL language contains a number of features specifically designed to simultaneously satisfy both requirements. The resulting treatment of data types includes provision for programmer-defined data types data types and generic routines programmer control over type conversion and very flexible data type behavior in a context that allows efficient compiled code and compact data representation. data types modes mode unions type conversion coercion generic functions extensible languages data type definition data description language compilation
