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#!/bin/env python
# -*- coding: utf-8 -*-
# Copyright (C) 2022 Iván Alejandro Ávalos Díaz <avalos@disroot.org>
# Edgar Alexis López Martínez <edgarmlmp@gmail.com>
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
from enum import Enum
from tabla import LexToken, TablaLex, tokens
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
def want(self, *want: Token) -> (LexToken | Error):
'''Requires the next token to have a matching ltok. Returns
that token, or an 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)
def _try(self, *want: Token) -> (LexToken | NoReturn):
'''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.
'''
tok: LexToken = self.lex()
if len(want) == 0:
return tok
for w in want:
if tok.tipo == w:
return tok
self.unlex()
def peek(self, *want: Token) -> (LexToken | NoReturn):
'''Looks for a matching ltok from the lexer, unlexes the
token, and returns it; or void if it was not an ltok.
'''
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()
def synassert(self, cond: bool, msg: str, numlinea: int) -> (Error | NoReturn):
'''Returns a syntax error if cond is false and void
otherwise.
'''
if not cond:
return Error(msg = msg, numlinea = numlinea)
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