parsing.py

"""Discrepancy parsing logic for extracting discrepancies from LLM output."""

import logging
import re

logger = logging.getLogger(__name__)


def parse_discrepancies(text: str) -> list[str] | None:
    """
    Extract list items (discrepancies) from model output.

    Replicates the _extract_list_items logic from scicoqa/inference/discrepancy_eval.py

    Args:
        text: Raw text output from LLM

    Returns:
        List of discrepancy strings, or None if no discrepancies found
    """
    if not text:
        return None

    # Remove redacted reasoning if present
    if "</think>" in text:
        text = text.split("</think>")[1]

    # Detect YAML or dashed list format
    if "```yaml\ndiscrepancies:" in text:
        text = text.split("```yaml\ndiscrepancies:")[-1]
        yaml_or_dashed = True
    elif "```yaml" in text:
        text = text.split("```yaml")[-1]
        yaml_or_dashed = True
    elif "discrepancies:" in text:
        text = text.split("discrepancies:")[1]
        yaml_or_dashed = True
    elif re.search(r"# Discrepancies[\s\r\n]*-", text, re.IGNORECASE):
        text = re.split(
            r"# Discrepancies[\s\r\n]*-", text, maxsplit=1, flags=re.IGNORECASE
        )[1]
        text = "- " + text
        yaml_or_dashed = True
    else:
        yaml_or_dashed = False

    if yaml_or_dashed:
        # Clean up the text
        text = text.strip("\n").strip().strip("```yaml").strip("```").strip("\n")
        text = (
            text.strip("discrepancies:").strip("discrepancies").strip("\n").strip()
        )

        # Split by list item pattern
        pattern = r"\n\s{0,2}-\s+"
        parts = re.split(pattern, text)

        items = []
        for part in parts:
            cleaned = " ".join(part.split())
            if cleaned and not cleaned.startswith("discrepancies:"):
                # Multiple cleaning passes
                cleaned = cleaned.strip().strip("-").strip()
                cleaned = cleaned.strip().strip("-").strip()
                cleaned = cleaned.strip().strip("|").strip()
                cleaned = cleaned.strip().strip(">-").strip()
                cleaned = cleaned.strip().strip(">").strip()
                cleaned = cleaned.strip().strip('"').strip()
                cleaned = cleaned.strip().strip("'").strip()
                cleaned = cleaned.strip("summary: |\n")
                cleaned = cleaned.strip("summary: ")
                cleaned = cleaned.strip("|")
                cleaned = cleaned.strip("\n").strip()
                # Remove numbered prefixes
                cleaned = re.sub(r"^[0-9]+[\.\)]\s*", "", cleaned)
                if cleaned:  # Only add non-empty items
                    items.append(cleaned)
    else:
        items = None

    # Handle empty list case
    if items and len(items) == 1 and items[0].strip() == "[]":
        items = None

    return items if items else None