Extensibility and Two Level Recognition,

Extensible languages permit the user to mold the language in a limited number to his problem andor style. When the extension mechanisms are sufficiently complex, a number of recognition related problems arise. These include how the user can specify an extension without having to know the recognition algorithm used by the compiler and how the compiler can efficiently recognize a dynamically varying language. Error detection and recovery is also much more difficult when the language is dynamic. The paper presents the partial solutions which the designers of LSD have developed and are implementing at Brown University. Results from a prototype implementation are described. Author