rl

Kent Wittenburg [email protected].

The RL files contain code for defining relational grammars

and using them in a bottom-up parser to recognise and/or parse

expressions in Relational Languages.

The approach is a simplification of that described in

Wittenburg, Weitzman, and Talley (1991), Unification-Based

Grammars and Tabular Parsing for Graphical Languages, Journal

of Visual Languages and Computing 2:347-370. This code is

designed to support the definition and parsing of Relational

Languages, which are characterised as sets of objects standing

in user-defined relations.

Correctness and completeness is independent of the order in

which the input is given to the parser. Data to be parsed can

be in many forms as long as an interface is supported for

queries and predicates for the relations used in grammar

productions.

To date, this software has been used to parse recursive

pen-based input such as math expressions and flow charts; to

check for data integrity and design conformance in databases;

to automatically generate constraints in drag-and-drop style

graphical interfaces; and to generate graphical displays by

parsing relational data and generating output code.

requires: Common Lisp

ports: Allegro Common Lisp 4.1, Macintosh Common Lisp 2.0

.

(1992/10/31)