RIFL : a language with filtered iterators

Abstract

RIFL is a new programming language that enables developers to write only common-case code to robustly process structured inputs. RIFL eliminates the need to manually handle errors with a new control structure, filtered iterators. A filtered iterator treats inputs as collections of input units, iterates over the units, uses the program itself to filter out unanticipated units, and atomically updates program state for each unit. Filtered iterators can greatly simplify the development of robust programs. We formally define filtered iterators in RIFL. The semantics of filtered iterators ensure that each input unit affects program execution atomically. Our benchmarks show that using filtered iterators reduces an average of 41.7% lines of code, or 58.5% conditional clauses and 33.4% unconditional computation, from fully manual implementations.