local sel_text = editor:GetSelText()
if sel_text == "" then print("Выделите текст для обработки!") end
local sel_start = editor.SelectionStart
local sel_end = editor.SelectionEnd

local text_out = ""
for i = sel_start, sel_end-1 do
    local char = editor:textrange(i, i+1)
    if char == "\t" then
        local space_count = editor.Column[i+1] - editor.Column[i]
        text_out = text_out..string.rep(" ", space_count)
    else
        text_out = text_out..char
    end
end

editor:ReplaceSel(text_out)