You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
77 lines
2.8 KiB
Python
77 lines
2.8 KiB
Python
# Copyright 2016 Grist Labs, Inc.
|
|
#
|
|
# 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.
|
|
|
|
import bisect
|
|
import re
|
|
from typing import Dict, List, Tuple
|
|
|
|
_line_start_re = re.compile(r'^', re.M)
|
|
|
|
class LineNumbers(object):
|
|
"""
|
|
Class to convert between character offsets in a text string, and pairs (line, column) of 1-based
|
|
line and 0-based column numbers, as used by tokens and AST nodes.
|
|
|
|
This class expects unicode for input and stores positions in unicode. But it supports
|
|
translating to and from utf8 offsets, which are used by ast parsing.
|
|
"""
|
|
def __init__(self, text):
|
|
# type: (str) -> None
|
|
# A list of character offsets of each line's first character.
|
|
self._line_offsets = [m.start(0) for m in _line_start_re.finditer(text)]
|
|
self._text = text
|
|
self._text_len = len(text)
|
|
self._utf8_offset_cache = {} # type: Dict[int, List[int]] # maps line num to list of char offset for each byte in line
|
|
|
|
def from_utf8_col(self, line, utf8_column):
|
|
# type: (int, int) -> int
|
|
"""
|
|
Given a 1-based line number and 0-based utf8 column, returns a 0-based unicode column.
|
|
"""
|
|
offsets = self._utf8_offset_cache.get(line)
|
|
if offsets is None:
|
|
end_offset = self._line_offsets[line] if line < len(self._line_offsets) else self._text_len
|
|
line_text = self._text[self._line_offsets[line - 1] : end_offset]
|
|
|
|
offsets = [i for i,c in enumerate(line_text) for byte in c.encode('utf8')]
|
|
offsets.append(len(line_text))
|
|
self._utf8_offset_cache[line] = offsets
|
|
|
|
return offsets[max(0, min(len(offsets)-1, utf8_column))]
|
|
|
|
def line_to_offset(self, line, column):
|
|
# type: (int, int) -> int
|
|
"""
|
|
Converts 1-based line number and 0-based column to 0-based character offset into text.
|
|
"""
|
|
line -= 1
|
|
if line >= len(self._line_offsets):
|
|
return self._text_len
|
|
elif line < 0:
|
|
return 0
|
|
else:
|
|
return min(self._line_offsets[line] + max(0, column), self._text_len)
|
|
|
|
def offset_to_line(self, offset):
|
|
# type: (int) -> Tuple[int, int]
|
|
"""
|
|
Converts 0-based character offset to pair (line, col) of 1-based line and 0-based column
|
|
numbers.
|
|
"""
|
|
offset = max(0, min(self._text_len, offset))
|
|
line_index = bisect.bisect_right(self._line_offsets, offset) - 1
|
|
return (line_index + 1, offset - self._line_offsets[line_index])
|
|
|
|
|