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from enum import Enum
from tabla import LexToken, TablaLex, tokens
from arbol import Arbol, Nodo
from shared import Control
from pprint import pprint
from errors import Error
from typing import NoReturn
from more_itertools import seekable
from nanoiter import NanoIter
from tabla import TablaLex, Token
from errors import Error
class BaseParser:
def __init__(self, iterador: NanoIter):
self.iterador: NanoIter = iterador
''' Requires the next token to have a matching ltok. Returns that
token, or an error. '''
def want(self, *want: Token) -> (LexToken | Error):
tok: LexToken = self.lex()
if len(want) == 0:
return tok
for w in want:
if tok.tipo == w:
return tok
return Error.syntax(tok.tipo, want, tok.numlinea)
''' Looks for a matching ltok from the lexer, and if not present,
unlexes the token and returns void. If found, the token is
consumed from the lexer and is returned. '''
def _try(self, *want: Token) -> (LexToken | NoReturn):
tok: LexToken = self.lex()
if len(want) == 0:
return tok
for w in want:
if tok.tipo == w:
return tok
self.unlex()
''' Looks for a matching ltok from the lexer, unlexes the token,
and returns it; or void if it was not an ltok. '''
def peek(self, *want: Token) -> (LexToken | NoReturn):
tok: LexToken = self.iterador.peek()
if len(want) == 0:
return tok
for w in want:
if tok.tipo == w:
return tok
def lex(self):
return self.iterador.next()
def unlex(self):
self.iterador.back()
''' Returns a syntax error if cond is false and void otherwise '''
def synassert(self, cond: bool, msg: str) -> (Error | NoReturn):
if not cond:
return Error(msg = msg)
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