"""
Utility class which converts 0-indexed absolute positional value
of the input text into 1-indexed line number and column number.
"""
from dataclasses import InitVar, dataclass, field
__all__ = ['CharLoc']
[docs]@dataclass
class CharLoc:
"""
The position (starting or ending) of a token within the input text
useful for line and column information in error messages.
"""
input_text: InitVar[str]
pos: InitVar[int]
#: 1-index line number
line: int = field(init=False)
#: 1-index column index value
col: int = field(init=False)
def __post_init__(self, input_text: str, pos: int):
self.line = input_text.count('\n', 0, pos) + 1
try:
self.col = pos - input_text.rindex('\n', 0, pos)
except ValueError:
self.col = pos + 1
@property
def rendered(self) -> str:
"""
The rendered string containing the line and column integer values.
"""
return f"line {self.line} col {self.col}"