DanCip/lca-StartingPoints-expanded

🧠 LCA-Starting Points

A benchmark for evaluating project-local code completion ranking. Curated to validate TreeRanker (ASE2025).

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📖 Dataset Description

Starting Points is a specialized dataset designed to evaluate code completion ranking, with a specific focus on locally defined identifiers (project-specific APIs) in Python.

Most LLM benchmarks focus on global APIs (standard libraries). However, developers spend significant time using APIs defined within their own projects. Starting Points targets this "blind spot" by testing how well models can resolve and rank identifiers that are defined within the user's current repository but may not be visible in the immediate file context.

This dataset is a refined subset of the Long Code Arena, enriched with:

• Static Analysis Data: Valid completions resolved by the Jedi library.
• Real-World IDE Suggestions: Ranked candidate lists generated by IntelliJ IDEA.

⚡ Key Features

• Focus: Project-specific API completion (vs. standard library).
• Language: Python.
• Source: Large projects with rich user-defined classes and functions.
• Goal: Benchmark ranking algorithms for local development environments.

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📂 Dataset Structure

Data Instances

Each instance represents a specific cursor position in a Python file where a dereference operation (e.g., object.) occurs. The task is to predict the correct next identifier from a list of candidates.

📊 Data Fields

This dataset includes rich metadata to facilitate deep analysis of ranking performance, surpassing the original details in the paper.

Field	Type	Description
idx	int64	Unique identifier for the dataset entry.
idx_lca	int64	Original index of the file in the Long Code Arena benchmark.
repo	string	Name of the source repository.
commit_hash	string	Specific commit hash used for the snapshot.
target_file	string	Path to the file within the repository.
offset	int64	Character offset (cursor position) where completion is triggered.
prefix	string	Source code content preceding the cursor (the context).
ground_truth	string	The actual identifier the developer typed (target label).
completion_type	string	Metadata describing the completion scenario.
start_with_	bool	True if the ground truth starts with an underscore _.
first_occurrence	bool	True if the identifier has not appeared previously in the prefix (file context). Useful for evaluating "unseen" identifier performance.
in_completions	bool	True if ground_truth is present in the intellij_completions list.
intellij_completions	sequence[string]	Ranked list of candidates from IntelliJ IDEA's completion engine.
jedi_completions	list[struct]	List of valid completions from Jedi, including name and type.
non_dunder_count_intellij	int64	Count of IntelliJ candidates excluding dunder methods (e.g., __init__).
non_dunder_count_jedi	int64	Count of Jedi candidates excluding dunder methods.
line_type_lca	string	Inherited metadata from Long Code Arena regarding line classification.

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🛠️ Dataset Creation

Curation Rationale

Standard benchmarks often overlook the difficulty of ranking identifiers that are local to a specific project. This dataset was created to test model performance in this realistic, everyday scenario where context from other files in the repository is crucial.

Source Data

• Origin: Long Code Arena benchmark.
• Filtering:
  • Dereference Detection: Uses tree-sitter to find . operators.
  • Static Analysis: Uses Jedi to resolve object types.
  • Scope Constraint: Retains only suggestions defined within the same repository, excluding standard library calls.
  • Quality Control: Requires the ground truth to be in the IntelliJ candidate list and the list to have at least 5 non-trivial items.

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📚 Citation

If you use this dataset, please cite the original paper:

@article{cipollone2025treeranker,
  title={TreeRanker: Fast and Model-agnostic Ranking System for Code Suggestions in IDEs},
  author={Cipollone, Daniele and Bogomolov, Egor and van Deursen, Arie and Izadi, Maliheh},
  journal={arXiv preprint arXiv:2508.02455},
  year={2025}
}