#  Copyright (c) PARRRATE T&V 2021. All rights reserved.
from bu4.evaluation.constructs.elambda import ELambda
from bu4.evaluation.constructs.evalue import EValue
from bu4.evaluation.sync import sync
from bu4.tracing.probe import ProbeA

__all__ = ('trace',)

_probe_index = 0


def trace(lambda_: EValue):
    global _probe_index
    size = 0
    while True:
        if not isinstance(lambda_, ELambda):
            return size, lambda_
        lambda_ = sync(lambda_.call(ProbeA(_probe_index)))
        _probe_index += 1
        size += 1