ABSTRACT DATA TYPES IN ADA.

Abstract data types are a type encapsulation concept for designing modular, well-structured software. Ada has a package construct for statically encapsulating groups of related declarations, and provides for abstract data type declarations using limited private types within packages. Other systems programming languages, such as CLU, provide a distinct class encapsulation construct for implementing abstract data types. The mechanism adopted by Ada is compared with a distinct class construct. A number of disadvantages of this mechanism for Ada language users is indicated.