# Copyright 2019 The Forte Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Forte Span module.
"""
from functools import total_ordering
__all__ = [
"Span",
]
[docs]@total_ordering
class Span:
r"""A class recording the span of annotations. :class:`Span` objects can
be totally ordered according to their ``begin`` as
the first sort key and ``end`` as the second sort
key.
Args:
begin: The offset of the first character in the span.
end: The offset of the last character in the span + 1. So the
span is a left-closed and right-open interval ``[begin, end)``.
"""
def __init__(self, begin: int, end: int):
if not isinstance(begin, int) or not isinstance(end, int):
raise ValueError(
f"Begin and End for an annotation must be integer, "
f"got {begin}:{type(begin)} and {end}:{type(end)}"
)
if begin > end:
raise ValueError(
f"The begin {begin} of span is greater than the end {end}"
)
if begin < 0:
raise ValueError("The begin cannot be negative.")
self.begin = begin
self.end = end
def __repr__(self):
return f"({self.begin}, {self.end})"
def __lt__(self, other):
if self.begin == other.begin:
return self.end < other.end
return self.begin < other.begin
def __eq__(self, other):
return (self.begin, self.end) == (other.begin, other.end)
def __hash__(self):
return hash((self.begin, self.end))
def __getstate__(self):
state = self.__dict__.copy()
return state
def __setstate__(self, state):
self.__dict__.update(state)