getLine package:text-rope

getLine :: Word -> TextLines -> TextLines
text-rope Data.Text.Lines Data.Text.Utf16.Lines Data.Text.Utf8.Lines
Get line with given 0-based index, O(1). The result does not contain \n characters.. Returns mempty if the line index is out of bounds. 
>>> :set -XOverloadedStrings

>>> map (\l -> getLine l "fя𐀀\n☺bar\n\n") [0..3]
["fя𐀀","☺bar","",""]
getLine :: Word -> Rope -> Rope
text-rope Data.Text.Mixed.Rope Data.Text.Rope Data.Text.Utf16.Rope Data.Text.Utf8.Rope
Get a line by its 0-based index. Returns mempty if the index is out of bounds. The result doesn't contain \n characters. 
>>> :set -XOverloadedStrings

>>> map (\l -> getLine l "foo\nbar\n😊😊\n\n") [0..3]
["foo","bar","😊😊",""]