"""
Persistent Topological Helicity & Linkage (PTHL) utilities
持久拓扑螺旋度与链接度(PTHL)工具

Interface requiring specialized libraries or custom pipelines.
接□口依赖专用库或自定义管线；当前提供占位并抛出ImportError。
"""

from __future__ import annotations

import numpy as np


def pthl_pipeline(struct_coords: np.ndarray) -> np.ndarray:
    """
    Placeholder function for PTHL computation.
    PTHL计算的占位函数。
    """
    raise ImportError("PTHL pipeline requires additional libraries; please install giotto-tda/gudhi")


__all__ = ["pthl_pipeline"]

