--prof(1,test_a1)
function avg(fn,name)
    local max, sum, results, D, avg, variance = 10, 0, {}, 0
    for i=1,max do
        local res = prof(1,fn) --fn x1000 times
        sum = sum + res
        results[i] = res
    end
    avg = math.floor( (sum / max) * 1000 + 0.5 ) / 1000
    for i=1,max do
        D = D + (results[i] - avg) * (results[i] - avg)
    end
    variance = math.floor( math.sqrt(D) * 1000 + 0.5) / 1000
    print(tostring(name).." Avg Time: "..tostring(avg)..", Variance: "..tostring(variance))
end




a = {}
b = {}
for i=1,50000 do
    a[i] = i
    local random_key = string.char(math.random(97,122))..tostring(i)..string.char(math.random(97,122))..string.char(math.random(97,122))
    b[random_key] = i
end

--Avg Time: 3.895, Variance: 0.013
function test_a1()
    for i=1,50000 do
        a[i] = a[i] + 1
    end
end

--Avg Time: 2.182, Variance: 0.013
function test_a2()
    local a = a
    for i=1,50000 do
        a[i] = a[i] + 1
    end
end

--a22 Avg Time: 2.177, Variance: 0.008
function test_a22()
    local a = a
    for i=1,#a do
        a[i] = a[i] + 1
    end
end

--a3 Avg Time: 3.67, Variance: 0.017
function test_a3()
    local a = a
    for i,v in ipairs(a) do
        a[i] = v + 1
    end
end

--a4 Avg Time: 4.494, Variance: 0.018
function test_a4()
    for i,v in ipairs(a) do
        a[i] = v + 1
    end
end

--a5 Avg Time: 4.261, Variance: 0.012
function test_a5()
    for i,v in pairs(a) do
        a[i] = v + 1
    end
end

--a6 Avg Time: 2.176, Variance: 0.009
function test_a6()
    local a = a
    for i=1,#a do
        local v = a[i] --now we have i and v as if use ipairs.
        a[i] = v + 1 --here we are using local cache.
    end
end

--b1 Avg Time: 6.782, Variance: 0.23
function test_b1()
    for k,v in pairs(b) do
        b[k] = v + 1
    end
end

--b2 Avg Time: 6.199, Variance: 0.159
function test_b2()
    local b = b
    for k,v in pairs(b) do
        b[k] = v + 1
    end
end

--b3 Avg Time: 6.22, Variance: 0.271
function test_b3()
    local b = b
    local pairs = pairs
    for k,v in pairs(b) do
        b[k] = v + 1
    end
end

local t = {
    a = a, --stage 1
    b = b,
    x = {
        y = {
            z = {
                a = a, --stage 4
                b = b,
            },
        },
    },
}

--a7 Avg Time: 3.487, Variance: 0.013
function test_a7()
    local t = t
    for i=1,#t.a do
        t.a[i] = t.a[i] + 1
    end
end

--a8 Avg Time: 7.06, Variance: 0.015
function test_a8()
    local t = t
    for i=1,#t.x.y.z.a do
        t.x.y.z.a[i] = t.x.y.z.a[i] + 1
    end
end

--a9 Avg Time: 17.125, Variance: 0.04
function test_a9()
    local t = t
    for i=1,#t.x.y.z.a do
        if t ~= nil and t.x ~= nil and t.x.y ~= nil and t.x.y.z ~= nil and t.x.y.z.a ~= nil then
            t.x.y.z.a[i] = t.x.y.z.a[i] + 1
        end
    end
end

-- a10 Avg Time: 4.636, Variance: 0.01
function test_a10()
    local t = t
    for i=1,#t.x.y.z.a do
        local aa = t.x.y.z.a
        aa[i] = aa[i] + 1
    end
end

--a11 Avg Time: 2.779, Variance: 0.011
function test_a11()
    local t = t
    for i=1,#t.a do
        local aa = t.a
        aa[i] = aa[i] + 1
    end
end

--a12 Avg Time: 3.371, Variance: 0.013
function test_a12()
    local t = t
    for i=1,#t.a do
        local aa = t.a
        local cc = t.c -- does not exist!
        aa[i] = aa[i] + 1
    end
end

--a13 Avg Time: 3.436, Variance: 0.008
function test_a13()
    local t = t
    for i=1,#t.a do
        local aa = t.a
        local bb = t.b -- exists!
        aa[i] = aa[i] + 1
    end
end

function test_all()
    avg(test_a1,"a1")
    avg(test_a2,"a2")
    avg(test_a22,"a22")
    avg(test_a3,"a3")
    avg(test_a4,"a4")
    avg(test_a5,"a5")
    avg(test_a6,"a6")
    avg(test_a7,"a7")
    avg(test_a8,"a8")
    avg(test_a9,"a9")
    avg(test_a10,"a10")
    avg(test_a11,"a11")
    avg(test_a12,"a12")
    avg(test_a13,"a13")
    avg(test_b1,"b1")
    avg(test_b2,"b2")
    avg(test_b3,"b3")
end