DIANA, the Descriptive Intermediate Attributed Notation for Ada, is an intermediate language

Intermediate language

In computer science, an intermediate language is the language of an abstract machine designed to aid in the analysis of computer programs. The term comes from their use in compilers, where a compiler first translates the source code of a program into a form more suitable for code-improving...

 used to represent the semantics of an Ada

Ada (programming language)

Ada is a structured, statically typed, imperative, wide-spectrum, and object-oriented high-level computer programming language, extended from Pascal and other languages...

 program. It was originally designed as an interface between the front end (syntactic analysis) and middle (semantic analysis) of the compiler on the one hand and the back end (code generation and optimization) on the other. It is also used as an internal representation by other language tools.

DIANA is also used by PL/SQL

PL/SQL

PL/SQL is Oracle Corporation's procedural extension language for SQL and the Oracle relational database...

, which is based on Ada.

DIANA is an abstract data type; its concrete implementations are defined using the IDL specification language

IDL specification language

IDL is a software interface description language created by William Wulf and John Nestor of Carnegie Mellon University and David Lamb of Queen's University, Canada.Like other interface description languages, IDL defined interfaces in a language- and machine- independent way, allowing...

.

DIANA descends from TCOL and AIDA, earlier representations of Ada programs.