Seminar: Context-Aware Scanning for Parsing Extensible Languages

Date: December 06, 2007 (Thursday) at 13:15

Speaker:
Dr. Eric van Wyk, University of Minnesota

Title:
Context-Aware Scanning for Parsing Extensible Languages

Abstract:
A program can often be clarified by using language features tailored to the task at hand. These domain-specific features typically do not exist in general purpose languages and one approach to making such high-level features available is extensible languages. An extensible programming language allows a programmer to import into his or her extensible "host" language the unique combination of domain-specific language features that raise the level of abstraction of the language to that of a particular problem domain.

Among the challenges to implementing such extensible languages is the problem of scanning and parsing. In this talk, I describe new parsing and context-aware scanning algorithms in which the scanner uses contextual information to disambiguate lexical syntax. The parser utilizes a slightly modified LR-style algorithm that passes to the scanner the set of valid symbols that the scanner may return at that point in parsing. I will also describe an analysis that checks that a deterministic scanner and parser can be generated from the declarative specifications; regular expressions specify the scanner and a context free grammar specifies the parser.

Room: E:1408