Incremental Dynamic Semantics for Language-Based Programming Environments

Attribute grammars are a formal notation for expressing the static semantics of programming languages — those properties that can be derived from inspection of the program text. Attribute grammars have become popular as a mechanism for generating language-based programming environments that incrementally perform symbol resolution, type checking, code generation and derivation of other static semantic properties as the program is modified. However, attribute grammars are not suitable for expressing dynamic semantics — those properties that reflect the history of program execution and/or user interactions with the programming environment. This article presents action equations, an extension of attribute grammars suitable for specifying the static and the dynamic semantics of programming languages. It describes how action equations can be used to generate language-based programming environments that incrementally derive static and dynamic properties as the user modifies and debugs the program