from dataclasses import dataclass
from typing import Union, Optional, List
from eazzyformat.string_iterators import StringIteratorWithNewlinesCounting
class BaseEazzyFormatSyntaxError(Exception):
character_state: str
def __init__(self, character_number: int, character: str, line_number: int):
self.character_number = character_number
self.character = character
self.line_number = line_number
def __str__(self):
return (
f"{self.character_state} character '{self.character}' on line "
f"{self.line_number}, character number {self.character_number}"
)
class UnexpectedCharacter(BaseEazzyFormatSyntaxError):
character_state = "Unexpected"
class UnclosedCharacter(BaseEazzyFormatSyntaxError):
character_state = "Unclosed"
class NothingToParse(Exception):
pass
class ListEnded(Exception):
pass
EazzyObject = Union[str, List["EazzyObject"]]
@dataclass
class ParsingResult:
parsed_object: EazzyObject
rest_index: Optional[int]
def _parse_eazzyformat_object(
string_iterator: StringIteratorWithNewlinesCounting) -> EazzyObject:
try:
character = string_iterator.skip(" \n\t")
except StopIteration:
raise NothingToParse from None
else:
if character == "[":
parsed_objects_list = []
character_number = string_iterator.previous_character_number
line_number = string_iterator.line_number
while True:
try:
parsed_object = _parse_eazzyformat_object(string_iterator)
except NothingToParse:
raise UnclosedCharacter(
character_number, "[", line_number
) from None
except ListEnded:
break
else:
parsed_objects_list.append(parsed_object)
return parsed_objects_list
elif character == "]":
raise ListEnded
elif character == "\"":
character_number = string_iterator.previous_character_number
line_number = string_iterator.line_number
try:
string = string_iterator.collect_to("\"")
next(string_iterator)
return string
except StopIteration:
raise UnclosedCharacter(
character_number, "\"", line_number
) from None
else:
raise UnexpectedCharacter(
string_iterator.previous_character_number,
character, string_iterator.line_number
)
def parse_eazzyformat(string: str) -> ParsingResult:
"""
Returns a string or list. Every list can contain other lists or strings
Can raise NothingToParse
"""
string_iterator = StringIteratorWithNewlinesCounting(string)
parsed_object = _parse_eazzyformat_object(string_iterator)
text_after_object_index = string_iterator.index
try:
string_iterator.skip(" \n\t")
except StopIteration:
return ParsingResult(parsed_object, rest_index=None)
else:
return ParsingResult(parsed_object, rest_index=text_after_object_index)
