Module:MOS

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This module primarily serves as a library for other modules and has no corresponding template.

This module provides functions for working with MOS scales in Lua code.

Introspection summary for Module:MOS
Functions provided (3) Line Function Params 14 new (nL, ns, equave) 22 parse (unparsed) 35 as_string (mos)	Lua modules required (3) Variable Module Functions used et Module:ET dependency not used rat Module:Rational new parse as_ratio seq Module:Sequence dependency not used

No function descriptions were provided. The Lua code may have further information.

---

local rat = require('Module:Rational')
local seq = require('Module:Sequence')
local et = require('Module:ET')
local p = {}

local common_name = {
	['3/2'] = 'fifth'
}
local common_ratio = {
	['fifth'] = rat.new(3, 2)
}

-- create a MOS structure (nL)L (ns)s <equave>
function p.new(nL, ns, equave)
	local nL = nL or 5
	local ns = ns or 2
	local equave = equave or 2
	return { nL = nL, ns = ns, equave = equave }
end

-- parse a MOS structure
function p.parse(unparsed)
	local nL, ns, equave = unparsed:match('^(%d+[Ll])(%s*)(%d+[Ss])(%s*)(.-equivalent)$')
	if equave == nil then
		equave = 2
	end
	equave = common_ratio[equave] or rat.parse(equave)
	if nL == nil or ns == nil or equave == nil then
		return nil
	end
	return p.new(nL, ns, equave)
end

-- construct a string representation for a MOS structure
function p.as_string(mos)
	local suffix = nil
	if mos.equave ~= 2 then
		suffix = "<" .. rat.as_ratio(mos.equave):lower() .. ">" 
	end
	return mos.nL .. "L " .. mos.ns .. "s " .. suffix
end

return p