File

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−local math_abs = math.abs;
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−local math_ceil = math.ceil;
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−local math_floor = math.floor;
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−local math_log = math.log;
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−local math_max = math.max;
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−local math_min = math.min;
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−local unpack = table.unpack or unpack; --luacheck: ignore 113
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−
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−if math_log(10, 10) ~= 1 then
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−	-- Lua 5.1 COMPAT
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−	local log10 = math.log10;
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−	function math_log(n, base)
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−		return log10(n) / log10(base);
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−	end
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−end
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−
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−local large = {
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−	"k", 1000,
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−	"M", 1000000,
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−	"G", 1000000000,
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−	"T", 1000000000000,
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−	"P", 1000000000000000,
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−	"E", 1000000000000000000,
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−	"Z", 1000000000000000000000,
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−	"Y", 1000000000000000000000000,
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−}
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−local small = {
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−	"m", 0.001,
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−	"μ", 0.000001,
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−	"n", 0.000000001,
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−	"p", 0.000000000001,
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−	"f", 0.000000000000001,
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−	"a", 0.000000000000000001,
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−	"z", 0.000000000000000000001,
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−	"y", 0.000000000000000000000001,
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−}
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−
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−local binary = {
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−	"Ki", 2^10,
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−	"Mi", 2^20,
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−	"Gi", 2^30,
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−	"Ti", 2^40,
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−	"Pi", 2^50,
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−	"Ei", 2^60,
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−	"Zi", 2^70,
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−	"Yi", 2^80,
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−}
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−
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−local function adjusted_unit(n, b)
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−	local round = math_floor;
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−	local prefixes = large;
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−	local logbase = 1000;
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−	if b == 'b' then
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−		prefixes = binary;
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−		logbase = 1024;
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−	elseif n < 1 then
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−		prefixes = small;
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−		round = math_ceil;
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−	end
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−	local m = math_max(0, math_min(8, round(math_abs(math_log(math_abs(n), logbase)))));
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−	local prefix, multiplier = unpack(prefixes, m * 2-1, m*2);
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−	return multiplier or 1, prefix;
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−end
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−
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−-- n: number, the number to format
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−-- unit: string, the base unit
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−-- b: optional enum 'b', thousands base
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−local function format(n, unit, b) --> string
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−	local fmt = "%.3g %s%s";
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−	if n == 0 then
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−		return fmt:format(n, "", unit);
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−	end
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−	local multiplier, prefix = adjusted_unit(n, b);
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−	return fmt:format(n / multiplier, prefix or "", unit);
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−end
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−
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−return {
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−	adjust = adjusted_unit;
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−	format = format;
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−};