dataset_guide/GENERATION_AND_STRUCTURE.md

Generation And Structure

JSONL Schema

Minimal record:

{"text":"...","domain":"code_fim","difficulty":"medium","meta":{"lang":"python"}}

Recommended metadata:

{
  "text": "...",
  "domain": "code_fim",
  "difficulty": "hard",
  "meta": {
    "lang": "python",
    "repo": "owner/name",
    "path": "src/file.py",
    "license": "Apache-2.0",
    "source": "the-stack-v2",
    "mode": "psm"
  }
}

FIM Text Format

Primary order:

<|fim_prefix|>{prefix}<|fim_suffix|>{suffix}<|fim_middle|>{middle}

Secondary order:

<|fim_suffix|>{suffix}<|fim_prefix|>{prefix}<|fim_middle|>{middle}

Use primary order for most records and keep a smaller secondary slice for model robustness.

Balance Targets

The long-term target mix is:

• FIM records: majority share.
• Continuation/code generation records: minority but substantial share.
• Languages: Python, Rust, C/C++, JavaScript/TypeScript, Java, Go.
• Lengths: short, medium, and long records.
• Difficulty: easy, medium, hard.

Duplicate Policy

The duplicate key is a hash of normalized text content. A checkpoint is not upload-ready unless the in-bundle duplicate count is zero.