Module:Number

Documentation for this module may be created at Module:Number/doc

--
-- Module that contains functions related to numeric formatting or number manipulation
--

local p = {}

local numberSuffixes = {
        k = 1e3,
        m = 1e6,
        b = 1e9,
        t = 1e12,
        q = 1e15,
        s = 1e18,
        o = 1e21,
        n = 1e24,
        d = 1e30
    }
    
--Adds commas
function p.formatnum(number)
	if tonumber(number) == nil then
		return number
	else
		local result = number
		while true do
			-- Format in blocks of 3 digits at a time until formatting is complete
            local k
			result, k = string.gsub(result, "^(-?%d+)(%d%d%d)", '%1,%2')
			if k == 0 then
				break
			end
		end
		return result
	end
end    

--- Parses a string representation of a number with suffixes
-- @param str (string) The string to parse.
-- @return (number) The numeric value represented by the input string or 0 if the string is NaN.
function p.parseNumber(str)
	-- Empty/nil string.
	if not str or str == "" then 
		return 0 
	end

	-- If the input is already a number, return it.
	local number = tonumber(str)
    if number then
        return number
    end
    
    local numStr = str:sub(1, -2)
    local suffix = str:sub(-1):lower()
    
    if tonumber(numStr) then
    	local multiplier = numberSuffixes[suffix] or 1
    	return numStr * multiplier
    else
    	return 0
    end
end

--- Format a number with optional suffixes based on its magnitude.
-- @param number (number) The number to be formatted.
-- @param decimals (number) [optional] The number of decimals to include in the formatted output. Default is 2.
-- @return (string) The formatted number as a string
function p.abbreviateNumber(number, decimals)
	if type(number) ~= "number" then
        error("NaN")
    end
	-- Round to two decimals by default.
    decimals = decimals or 2

	for suffix, value in pairs(numberSuffixes) do
        if number >= value then
            if number % 1 ~= 0 then
                return string.format("%." .. decimals .. "f%s", number / value, suffix)
            else
                return string.format("%.0f%s", number / value, suffix)
            end
        end
    end

    return tostring(number)
end

-- Converts a string to a numeric value, or the default value if the
-- string isn't a number.
function p.toNumberOrDefault(str, def)
	local num = tonumber(str)
	if num then
		return num
	else
		return def
	end
end

-- Attempts to convert a string to a numeric value.
-- Throws an error if the value isn't a number.
function p.toNumberOrError(str, errorMsg)
	local num = tonumber(str)
	local msg = errorMsg
	
	if msg == nil then
		msg = "NaN"
	end
	
	if num then
		return num
	else
		error(msg)
	end
end

return p