builtup4/bu4/evaluation/av/lambdaenv.py

37 lines
1.0 KiB
Python

# Copyright (c) PARRRATE T&V 2021. All rights reserved.
from typing import Mapping, Iterator
from bu4.evaluation.av.envtype import envtype
from bu4.evaluation.constructs.evaluable import Evaluable
from bu4.evaluation.targets.avcontainer import AVContainer
__all__ = ('LambdaEnv',)
class LambdaEnv(Mapping[bytes, Evaluable]):
def __getitem__(self, k: bytes) -> Evaluable:
if k == self.name:
return self.container
else:
return self.env[k]
def __len__(self) -> int:
return len(self.env) + 1
def __iter__(self) -> Iterator[Evaluable]:
yield self.name
yield from self.env
def __init__(self, env: envtype, name: bytes, evaluable: Evaluable, *, memoize):
self.env = env
self.name = name
self.container = AVContainer(evaluable, name).after_value if memoize else evaluable
@staticmethod
def strfy(self):
return ''.join(f'\x7b{evaluable}|{name.decode()}\x7d' for name, evaluable in self.items())
def __str__(self):
return self.strfy(self)