Planet Dynamic or: How I Learned to Stop Worrying and Love Reflection

Abstract

A fundamental belief underlying forty years of programming languages research, aptly captured by the slogan “Well-typed programs can’t go wrong”, is that programs augmented with machine-checked annotations are more likely to be free of bugs. But of course, real programs do wrong and programmers are voting with their feet. Dynamic languages such as Ruby, Python, Lua, JavaScript and R are unencumbered by redundant type annotations and are increasingly popular. JavaScript, the lingua franca of the web, is moving to the server with the success of Node.js. R, another dynamic language, is being used in statistics, biology and finance for data analysis and visualization. Not only are these languages devoid of types, but they utterly lack any static structure that could be used for program verification. This talk will draw examples from recent results on JavaScript and R to illustrate the extent of the problem and propose some directions for research.