Spine: A Synthesizer for Practical Incremental Evaluators

SPINE is a system for efficiently generating practical incremental evaluators based on recursive procedures for the Strongly Non-Circular class of attribute grammars. Several interactive language-based software development environments use incremental evaluation of attribute grammars for context-sensitive static semantic analysis. Ease of evaluator construction, effective consumption of space, applicability to a large class of AGs, ability to handle multiple site attribute tree transformations and close to optimal performance are the key advantages this system offers over other existing incremental AG systems. SPINE has been used innovatively in the Ensemble software environment to provide advanced incremental formatting of documents. As part of this work, an AG-description language, ASPEC, was developed to serve as the presentation (layout) specification tool for Ensemble documents. The ASPEC language provides several powerful default mechanisms that make presentation specifications very concise.