LooPy: interactive program synthesis with control structures

One vision for program synthesis, and specifically programming by example (PBE), is an interactive programmer's assistant, integrated into the development environment. To make synthesis practical use, prior work on Small-Step Live PBE has proposed to limit scope of small code snippets, enable users provide local specifications those snippets. This paradigm, however, does not well in presence loops. We present LooPy, a synthesizer live environment, which extends inside loops scales it up synthesize larger while remaining fast enough use. allow effectively examples at various loop iterations, even when body incomplete, LooPy makes use execution , technique that leverages programmer as oracle step over incomplete parts loop. bodies speeds, introduces Intermediate State Graph new data structure, compactly represents large space snippets composed multiple assignment statements conditionals. evaluate empirically using benchmarks from competitive previous synthesizers, show can solve wide variety tasks speeds. also perform qualitative user study shows LooPy's block-level are easy programmers provide.