builtup4/bu4/parsing/constructs/lname.py

40 lines
1.1 KiB
Python

from bu4.evaluation.av.envtype import envtype
from bu4.linking.states.linkingstate import LinkingState
from bu4.parsing.codes import CODE_NAME, CODE_NULL
from bu4.parsing.constructs.linked import Linked, Parsed
from bu4.linking.states.linkingfinished import LinkingFinished
from bu4.evaluation.constructs.evaluable import Evaluable
__all__ = ('PName',)
class LName(Linked):
def __init__(self, promise: set[bytes], name: bytes):
assert name in promise, f'undefined: {name}'
self.name = name
self.future = {name}
def link(self) -> LinkingState:
return LinkingFinished(self)
def evaluable(self, env: envtype) -> Evaluable:
return env[self.name]
def __str__(self):
return f'[{self.name.decode()}]'
def unlink(self) -> Parsed:
return PName(self.name)
class PName(Parsed):
def __init__(self, name: bytes):
self.name = name
def link(self, promise: set[bytes]) -> Linked:
return LName(promise, self.name)
def __bytes__(self):
return bytes([CODE_NAME, *self.name, CODE_NULL])