ShiftList

--[[
    ShiftList by darraghd493

    A list that shifts all elements to the right when a new element is added, and removes the last element when the list is full.
    This is useful for storing a fixed number of elements in a list, such as a history of values.
]]

local ShiftList = {
    -- Internal properties
    size = 0;
    items = {};
}
ShiftList.__index = ShiftList

function ShiftList.new(size: number)
    local self = setmetatable({
        size = size;
        items = {};
    }, ShiftList)
    for i=1,size do
        self.items[i] = nil
    end
    return self
end

function ShiftList:push(item: any)
    for i=1,self.size-1 do
        self.items[i+1] = self.items[i]
    end
    self.items[1] = item
end

function ShiftList:get(index: number)
    return self.items[index]
end

function ShiftList:set(index: number, item: any)
    self.items[index] = item
end

function ShiftList:remove(index: number)
    for i=index,self.size-1 do
        self.items[i] = self.items[i+1]
    end
    self.items[self.size] = nil
end

function ShiftList:find(item: any)
    for i=1,self.size do
        if self.items[i] == item then
            return i
        end
    end
    return nil
end

function ShiftList:contains(item: any)
    return self:find(item) ~= nil
end

function ShiftList:clear()
    for i=1,self.size do
        self.items[i] = nil
    end
end

function ShiftList:iterate()
    local index = 0
    return function()
        index = index + 1
        return self.items[index]
    end
end

return ShiftList