Sign In

Evaluating Code Similarity Across Programming Languages Using Abstract Syntax Tree Edit Distance and Large Language Models

Core Concepts
This study explores the effectiveness of Abstract Syntax Tree (AST) edit distance and large language model-based similarity metrics in evaluating code similarity across multiple programming languages, and compares their performance to traditional semantic similarity measures.
The paper revisits recent code similarity evaluation metrics, focusing on the application of Abstract Syntax Tree (AST) editing distance in diverse programming languages. The authors explore the usefulness of these metrics and compare them to traditional sequence similarity metrics like BLEU score and Jaccard similarity. The key highlights and insights are: The authors demonstrate the adaptability of the TSED (Tree Similarity of Edit Distance) metric beyond SQL, showing its effectiveness in languages like Java, Python, and Kotlin. TSED exhibits a strong correlation with BLEU score, Jaccard similarity, and GPT-based similarity, indicating its ability to capture intricate code structures. The evaluation compares TSED, GPT-based similarity, BLEU score, and Jaccard similarity against execution match, a metric that assesses the consistency in execution outcomes between generated code and ground truth. The results show that both TSED and GPT-based similarity exhibit higher accuracy in predicting execution match compared to the semantic metrics. The authors discuss the limitations of these metrics, including the unstable nature of GPT-based similarity scoring and the influence of parameter optimization on the TSED metric. They highlight the need to carefully balance performance and stability considerations in code similarity assessment across various programming languages. The paper proposes and publishes an adaptable TSED-based metric that demonstrates effectiveness across all tested languages, representing an enhanced version of the original TSED approach. Overall, the study provides valuable insights into the strengths and weaknesses of different code similarity evaluation techniques, and offers a comprehensive comparison of their performance across multiple programming languages.
The paper presents the following key statistics: TSED exhibits a Pearson correlation ranging from 0.6 to 0.8 with BLEU score and Jaccard similarity across the tested programming languages. TSED and GPT-based similarity show a strong correlation, especially in Java and Python, during the CoderEval test. The optimal thresholds for TSED and GPT-based similarity to match execution match results in F1 scores ranging from 0.50 to 0.68 and accuracy ranging from 0.53 to 0.68 across the tested languages. The GPT-based similarity scoring exhibits limited stability, with mean squared error and mean absolute error values ranging from 0.0527 to 0.0628 and 0.1825 to 0.1996, respectively, across multiple runs. The penalty weight for the 'Insert' operation in the TSED metric has a significant impact on the correlation with GPT-based similarity, with a sweet spot around 0.8 for the MBXP/Java dataset.
"TSED exhibits a commendable correlation ranging from 0.6 to 0.8 with BLEU score and Jaccard similarity, underscoring its sensitivity to code structure." "GPT similarity demonstrates a slightly superior F1 score and TSED gives good results on accuracy in matching with Execution-Match." "GPT scoring exhibits limited stability in the context of code similarity evaluation."

Deeper Inquiries

How can the stability of GPT-based similarity metrics be improved to ensure more reliable and consistent code assessments?

To enhance the stability of GPT-based similarity metrics for more reliable and consistent code assessments, several strategies can be implemented: Fine-tuning Models: Continuously fine-tuning the GPT models on a diverse set of code samples can help improve their stability. By exposing the models to a wide range of programming constructs and patterns, they can learn to provide more consistent similarity scores. Regular Updates: Keeping the GPT models up-to-date with the latest advancements in programming languages and coding practices can help in maintaining stability. Regular updates can address any drift in performance and ensure that the models are aligned with current coding standards. Ensemble Methods: Employing ensemble methods by combining the outputs of multiple GPT models can help mitigate the instability of individual models. By aggregating predictions from different models, the overall similarity scores can be more robust and reliable. Error Analysis and Feedback Loop: Implementing an error analysis mechanism to identify patterns in unstable predictions can provide insights for model improvement. Incorporating a feedback loop where incorrect predictions are used to retrain the models can lead to enhanced stability over time. Regular Monitoring: Monitoring the performance of GPT-based similarity metrics over time and setting up alerts for significant deviations can help in detecting and addressing stability issues promptly. Continuous monitoring allows for proactive adjustments to maintain consistency in code assessments. By implementing these strategies, the stability of GPT-based similarity metrics can be improved, leading to more reliable and consistent code assessments.

What other factors, beyond the AST structure and semantic similarity, could be incorporated into a comprehensive code similarity evaluation framework?

In addition to AST structure and semantic similarity, several other factors can be incorporated into a comprehensive code similarity evaluation framework to provide a more holistic assessment of code similarity: Execution Trace Analysis: Considering the execution traces of code snippets can offer valuable insights into their functional behavior. Comparing the execution paths and outcomes can help in assessing the practical similarity of code beyond syntactic and structural aspects. Code Comments and Documentation: Analyzing the comments and documentation within code files can provide context and additional information for code similarity evaluation. Incorporating natural language processing techniques to compare the textual content of comments can enhance the understanding of code similarities. Code Complexity Metrics: Integrating code complexity metrics such as cyclomatic complexity, nesting levels, and code churn can offer a quantitative measure of code similarity. Evaluating code based on its complexity can provide a more nuanced understanding of similarities and differences. Version Control History: Examining the version control history of code snippets can reveal evolution patterns and similarities across different versions. Comparing changes, commits, and branches can help in identifying commonalities and variations in code. Runtime Performance Analysis: Assessing the runtime performance of code segments can be another factor to consider in a comprehensive evaluation framework. Comparing the efficiency and speed of code execution can provide insights into similarities in algorithmic approaches. By incorporating these additional factors into a code similarity evaluation framework, a more comprehensive and multi-dimensional assessment of code similarities can be achieved.

How can the TSED metric be further optimized and generalized to handle a wider range of programming languages and code complexity levels?

To optimize and generalize the Tree Similarity of Edit Distance (TSED) metric for a wider range of programming languages and code complexity levels, the following approaches can be considered: Enhanced Parser Flexibility: Enhancing the flexibility of the AST parser used in TSED to accommodate a broader range of programming languages and code structures is crucial. Developing parsers that can handle diverse syntax and semantics will improve the applicability of TSED across different languages. Parameter Tuning: Fine-tuning the parameters in the TSED metric, such as penalty weights for delete, insert, and rename operations, can optimize its performance. Adapting these parameters based on the characteristics of specific programming languages can enhance the metric's effectiveness in capturing structural similarities. Normalization Techniques: Refining the normalization techniques in TSED to account for varying code complexities can improve its generalizability. Implementing normalization strategies that consider the size and intricacy of code structures will enable TSED to handle code of different levels of complexity. Benchmarking and Validation: Conducting extensive benchmarking across a diverse set of programming languages and codebases to validate the effectiveness of TSED is essential. By testing TSED on a wide range of scenarios and datasets, its robustness and generalizability can be verified. Integration of Machine Learning: Integrating machine learning techniques to adaptively adjust TSED parameters based on the characteristics of input code can enhance its versatility. Utilizing machine learning models to optimize TSED for specific languages and code patterns can improve its performance. By implementing these strategies, the TSED metric can be further optimized and generalized to handle a wider range of programming languages and code complexity levels, making it a more versatile and effective tool for code similarity evaluation.