JumpCoder: Go Beyond Autoregressive Coder via Online Modification

While existing code LLMs (code LLMs) exhibit impressive capabilities in code generation, their autoregressive sequential generation inherently lacks reversibility. This limitation hinders them from timely correcting previous missing statements during coding as humans do, often leading to error propagation and suboptimal performance. We introduce JumpCoder, a novel modelagnostic framework that enables online modification and non-sequential generation to augment the code LLMs. The key idea behind JumpCoder is to insert new code into the currently generated code when necessary during generation, which is achieved through an auxiliary infilling model that works in tandem with the code LLM. Since identifying the best infill position beforehand is intractable, we adopt an infill-first, judge-later strategy, which experiments with filling at the $k$ most critical positions following the generation of each line, and uses an Abstract Syntax Tree (AST) parser alongside the Generation Model Scoring to effectively judge the validity of each potential infill. Extensive experiments using six state-of-the-art code LLMs across multiple benchmarks consistently indicate significant improvements over all baselines. Notably, JumpCoder assists code LLMs in achieving up to a 3.6% increase in Pass@1 for Python, 6.3% for Java, and 3.7% for C++ in the multilingual HumanEval benchmarks. Our code is public at https://github.com/Keytoyze/JumpCoder.