"""Pure indicator functions (doc 02 §1).

Indicators are **pure functions**: they take a price array and parameters and
return an array. They must **not** hold state across calls. Strategy code
computes signals from these; the engine never calls them. Add your own custom
indicators (range filter, regime detector, …) here as the strategy requires.
"""
from .base import atr, ema, rsi, sma

__all__ = ["sma", "ema", "rsi", "atr"]