test_string_format.lua

local v1 = 1-5e-9
local v2 = 1-5e-9-1e-16
local function sprintf(...)
  io.write(string.format(...))
end

print("13 hex digits define a double, so these numbers are almost identical:")
sprintf("%.13a\n",v1)
sprintf("%.13a\n",v2)
print("However their \"%.8g\" representation is still different:")
sprintf("%.8g\n",v1)
sprintf("%.8g\n",v2)