--[[

General Lua Libraries for Lua 5.1, 5.2 & 5.3

Copyright (C) 2002-2018 stdlib authors

]]

--[[--

Additions to the core math module.

The module table returned by `std.math` also contains all of the entries from

the core math table. An hygienic way to import this module, then, is simply

to override the core `math` locally:

local math = require 'std.math'

@corelibrary std.math

]]

local _ = require 'std._base'

local argscheck = _.typecheck and _.typecheck.argscheck

_ = nil

local _ENV = require 'std.normalize' {

'math',

merge = 'table.merge',

}

--[[ ================= ]]--

--[[ Implementatation. ]]--

--[[ ================= ]]--

local M

local _floor = math.floor

local function floor(n, p)

if(p or 0) == 0 then

return _floor(n)

end

local e = 10 ^ p

return _floor(n * e) / e

end

local function round(n, p)

local e = 10 ^(p or 0)

return _floor(n * e + 0.5) / e

end

--[[ ================= ]]--

--[[ Public Interface. ]]--

--[[ ================= ]]--

local function X(decl, fn)

return argscheck and argscheck('std.math.' .. decl, fn) or fn

end

M = {

--- Core Functions

-- @section corefuncs

--- Extend `math.floor` to take the number of decimal places.

-- @function floor

-- @number n number

-- @int[opt=0] p number of decimal places to truncate to

-- @treturn number `n` truncated to `p` decimal places

-- @usage

-- tenths = floor(magnitude, 1)

floor = X('floor(number, ?int)', floor),

--- Round a number to a given number of decimal places.

-- @function round

-- @number n number

-- @int[opt=0] p number of decimal places to round to

-- @treturn number `n` rounded to `p` decimal places

-- @usage

-- roughly = round(exactly, 2)

round = X('round(number, ?int)', round),

}

return merge(math, M)