Files
Sheerka/src/parsers/ParserInput.py
T
2026-04-11 21:01:39 +02:00

120 lines
3.4 KiB
Python

from common.utils import get_text_from_tokens
from parsers.tokenizer import Token, TokenKind, Tokenizer
class ParserInput:
def __init__(self, text):
self.original_text = text
self.all_tokens: list = None
self.exception: Exception = None
self.pos: int = None
self.end: int = None
self.token: Token = None
def init(self) -> bool:
try:
# the eof if forced, but will not be yield if not set to.
self.all_tokens = list(Tokenizer(self.original_text, yield_eof=True))
self.pos = -1
self.end = len(self.all_tokens)
return True
except Exception as ex:
self.all_tokens = None
self.exception = ex
return False
def as_text(self, custom_switcher=None, tracker=None):
if self.all_tokens is None:
raise Exception("You must call init() first !")
return get_text_from_tokens(self.all_tokens, custom_switcher, tracker)
def reset(self):
if self.exception:
raise self.exception
self.pos = -1
def next_token(self, skip_whitespace=True) -> bool:
self.pos += 1
if self.pos >= self.end:
self.token = self.all_tokens[-1]
return False
self.token = self.all_tokens[self.pos]
if skip_whitespace:
while self.token.type in (TokenKind.WHITESPACE, TokenKind.NEWLINE):
self.pos += 1
if self.pos > self.end:
self.token = self.all_tokens[-1]
return False
self.token = self.all_tokens[self.pos]
if self.token.type == TokenKind.EOF:
return False
return True
def check_next_token(self, skip_whitespace=True):
"""
Returns the token after the current one
Never returns None (returns TokenKind.EOF instead)
"""
my_pos = self.pos + 1
if my_pos > self.end:
return self.all_tokens[-1]
if skip_whitespace:
while self.all_tokens[my_pos].type in (TokenKind.WHITESPACE, TokenKind.NEWLINE):
my_pos += 1
if my_pos > self.end:
return self.all_tokens[-1]
return self.all_tokens[my_pos]
def seek(self, pos):
"""
Move the token offset to position pos
:param pos:
:return: True is pos is a valid position False otherwise
"""
if pos < 0 or pos > self.end:
self.token = None
return False
self.pos = pos
self.token = self.all_tokens[self.pos]
return True
def clone(self):
res = ParserInput(self.original_text)
res.all_tokens = self.all_tokens
res.exception = self.exception
res.pos = self.pos
res.end = self.end
res.token = self.token
return res
@staticmethod
def from_tokens(tokens, text=None):
"""
returns a parser input, given already computed tokens
:param tokens:
:param text:
:return:
"""
res = ParserInput(None)
res.all_tokens = tokens
res.original_text = text or get_text_from_tokens(tokens)
res.pos = -1
res.end = len(res.all_tokens)
return res
def __repr__(self):
return f"ParserInput('{self.original_text}', len={len(self.all_tokens)})"