range.lua

View source code here on GitHub!

This module directly ports some of the logic found in Python's range.

range_entry3(start, step, idx)

Returns:

start + (step * idx)

Return type:

number

range_entry4(start, stop, step, idx)

Returns:

The idx^th entry of start,(stop-1),step

Return type:

number

-- This file is a direct port of Python's range functions

local function range_entry3(start, step, idx)
    return start + (step * idx)
end

local function range_entry4(start, stop, step, idx)
    local length = 0
    if step > 0 and start < stop then
        length = math.floor(1 + (stop - 1 - start) / step)
    elseif step < 0 and start > stop then
        length = math.floor(1 + (start - 1 - stop) / (-step))
    end
    if idx < 0 then
        idx = length + idx
    end
    if idx < 0 or idx >= length then
        return nil, "length is 0, cannot fetch"
    end
    return range_entry3(start, step, idx)
end

return {
    range_entry3 = range_entry3,
    range_entry4 = range_entry4,
}