A graphical structure-editor that generates code for attribute grammar systems.

Attribute Grammars were proposed by Donald Knuth (1968) as a tool for describing and implementing the semantics of programming languages. The number of attribute systems now-a-days is counted by tens, some of which are truly attribute systems (such as DELTA, FNC-2, and W/AGE) and other are loosely related to the formalism (such as YACC). Some of the systems are equipped with special input languages (OLGA for FUNC-2, ALADIN for GAG and SSL for the SYNTHESiZER GENERATOR) and others accept some variant of the attribute-grammar notation as their input. In all cases, the structure of the input, although written in different syntactical forms for different systems, reflects the underlying context-free grammar and the set of semantic rules associated with it. A graphical representation for attribute grammars, when built over an efficient recursive data structure, can be used as a base for code generation for attribute-grammar systems. To represent attribute grammars graphically, the basic constructs of the formalism must each have a corresponding graphical object that clearly shows its type and functionality. The Attribute Grammar Generator is a visual editing tool in which objects (graphical object) can be dynamically created and linked to form an attribute grammar. The program provides facilities for creating and linking three types of primitive objects Terminals, Nonterminals and Attributes. The program also provides several dynamic checking operations to inform the user about the consequences of the currently invoked action. The constructed attribute grammar can then be processed by a translator to generate code for previously selected tool such as W/AGE. Source: Masters Abstracts International, Volume: 34-02, page: 0793. Adviser: Richard Frost. Thesis (M.Sc.)--University of Windsor (Canada), 1995