local fmt = require "fmt"

local function map_range(a, b, s)
    return b[1] + (s - a[1]) * (b:back() - b[1]) / (a:back() - a[1])
end

local a = range(0, 10)
local b = range(-1, 0)
for a as s do
    local t = map_range(a, b, s)
    fmt.print("%2d maps to % g", s, t)
end