Projecting a Modular Future

Two innovations are enhancing programming languages' capabilities. First, modularity lets you combine independently developed languages without changing their respective definitions. A language is no longer a fixed quantity; you can extend it with domain-specific constructs as needed. Second, projectional editing lets you build editors and IDEs that don't require parsers. Such editors and IDEs support a range of tightly integrated notations, including textual, symbolic, tabular, and graphical notations. In addition, by avoiding parsers, they avoid grammar composition's well-known limitations. Three examples illustrate how these two innovations affect programming-language design. A set of modular extensions of C for embedded programming enables efficient code generation and formal analysis. A language for requirements engineering flexibly combines structured and unstructured (prose) data. Finally, a language for defining insurance rules uses mathematical notation. These examples all rely on the open source JetBrains MPS (Meta Programming System) language workbench. This article is part of a special issue on Software Architecture.