Module:Val

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

-- TODO put '0' in front of number like '.123'; remove signs from input uncertainties
local getArgs
local delimit_groups = require('Module:Gapnum').groups

-- Specific message for {{Val}} errors
local function valerror(msg, nocat)
	if is_test_run then  -- LATER remove
		return 'Error: "' .. msg .. '"'
	end
	local ret = mw.html.create('strong')
							:addClass('error')
							:wikitext('Error in {{Val}}: ' .. msg)
	-- Not in talk, user, user_talk, or wikipedia_talk
	if not nocat and not mw.title.getCurrentTitle():inNamespaces(1,2,3,5) then
		ret:wikitext('[[Category:Pages with incorrect formatting templates use]]')
	end
	return tostring(ret)
end

-- true/false whether or not the string is a valid number
-- ignores parentheses and parity symbolts
local function validnumber(n)
	-- Look for a number that may be surrounded by parentheses or may have +/-
	n = mw.ustring.match(tostring(n), '^%(?[±%-%+]?([%d\.]+)%)?$')
	return tonumber(n) ~= nil
end

local function get_builtin_unit(unitcode, definitions)
	-- Return table of information for the specified built-in unit, or nil if not known.
	-- Each defined unit code must be followed by two spaces (not tab characters).
	local _, pos = definitions:find('\n' .. unitcode .. '  ', 1, true)
	if pos then
		local endline = definitions:find('\n', pos, true)
		if endline then
			local result = {}
			local n = 0
			local text = definitions:sub(pos, endline - 1)
			for item in (text .. '  '):gmatch('(%S[^\n]-)%s%s') do
				if item == 'NOSPACE' then
					result.nospace = true
				elseif item == 'ANGLE' then
					result.isangle = true
					result.nospace = true
				else
					n = n + 1
					if n == 1 then
						result.symbol = item
					elseif n == 2 then
						result.link = item
					else
						break
					end
				end
			end
			if n == 2 then
				return result
			end
			-- Ignore invalid definition, treating it as a comment.
		end
	end
end

local function convert_lookup(ucode, options)
	local lookup = require('Module:Convert/sandbox')._unit
	return lookup(ucode, { value = options.value, link = options.want_link })
end

local function get_unit(ucode, value, want_link, want_longscale)
	local data = mw.loadData('Module:Val/units')
	local result = want_longscale and
		get_builtin_unit(ucode, data.builtin_units_long_scale) or
		get_builtin_unit(ucode, data.builtin_units)
	local convert_unit = convert_lookup(ucode, { value = value, link = want_link })
	if result then
		-- Have: result.symbol + result.link + result.isangle + result.nospace
		if want_link then
			result.text = '[[' .. result.link .. '|' .. result.symbol .. ']]'
		else
			result.text = result.symbol
		end
		result.sortkey = convert_unit.sortkey
	else
		result = {
			text = convert_unit.text,
			sortkey = convert_unit.sortkey,
		}
	end
	return result
end

local function makeunit(ucode, options)
	-- Return wikitext, sortkey for the requested unit and options.
	-- TODO The sortkey does not account for any per unit.
	local function bracketed(ucode, text)
		return ucode:find('[*./]') and '(' .. text .. ')' or text
	end
	options = options or {}
	local unit = get_unit(ucode, options.value, options.link, options.longscale)
	local text = unit.text
	local percode = options.per
	if percode then
		local perunit = get_unit(percode, 0, options.per_link, options.longscale)
		text = bracketed(ucode, text) .. '/' .. bracketed(percode, perunit.text)
	end
	if not unit.nospace then
		text = ' ' .. text
	end
	return { text = text, isangle = unit.isangle, sortkey = unit.sortkey }
end

-- TODO: Add other format options
local function delimit(n, fmt)
	local prefix, num
	if not fmt then fmt = '' end
	fmt = fmt:lower()
	-- look for + or - preceding the number
	if n:find('[-+]') then
		prefix, num = string.match(n, '([-+])([%d.]+)')
	else
		num = n
	end

	-- integer and decimal parts of number
	-- if there is no decimal part, delimit_groups only returns 1 table
	local ipart, dpart = delimit_groups(num)
	if fmt == 'commas' then
		num = table.concat(ipart, ',')
		if dpart then
			dpart = table.concat(dpart)
			num = num .. '.' .. dpart
		end
	elseif fmt == 'none' then
		-- TODO Why not use original num?
		num = table.concat(ipart)
		if dpart then
			dpart = table.concat(dpart)
			num = num .. '.' .. dpart
		end
	else
		-- Delimit with a small gap by default.
		num = {}
		num[1] = table.remove(ipart, 1)
		for _, v in ipairs(ipart) do
			table.insert(num, '<span style="margin-left:.25em">' .. v .. '</span>')
		end
		if dpart then
			table.insert(num, '.' .. table.remove(dpart, 1))
			for _, v in ipairs(dpart) do
				table.insert(num, '<span style="margin-left:.25em">' .. v .. '</span>')
			end
		end
		num = table.concat(num)
	end

	-- add prefix back if it had one
	if prefix then
		-- change hyphen to proper minus sign
		if prefix == '-' then
			prefix = '−'
		end
		num = prefix .. num
	end

	return tostring(num)
end

local function _main(number, uncertainty, unit_spec, misc_tbl)
	local e_10 = misc_tbl.e
	local fmt = misc_tbl.fmt

	-- Unit
	local unit_table, sortkey
	if unit_spec.u then
		unit_table = makeunit(unit_spec.u, {
						link = unit_spec.link,
						per = unit_spec.per,
						per_link = unit_spec.per_link,
						value = (tonumber(number.n) or 1) * (e_10 and 10^e_10 or 1),
						longscale = nil,  -- TODO set from 'long scale' parameter
					})
		sortkey = unit_table.sortkey
	else
		sortkey = convert_lookup('dummy', { value = number.n }).sortkey
	end

	-- Uncertainty
	local unc_text
	local uncU, uncL = uncertainty.upper, uncertainty.lower -- TODO caller should ensure uncU and uncL have no sign
	-- The entire number needs to be wrapped in parentheses if:
	--   the exponent parameter (e) is defined AND
	--   no lower uncertainty is defined AND
	--   upper uncertainty is defined and contains no parentheses
	local paren_wrap = e_10 and (not uncL and (uncU and not uncU:find('%(')))
	local paren_uncertainty
	if uncU then
		if uncL then
			local mSu = require('Module:Su')._main  -- sup/sub format
			uncU = '+' .. delimit(uncU, fmt) .. (uncertainty.upperend or '') 
			uncL = '−' .. delimit(uncL, fmt) .. (uncertainty.lowerend or '') 
			if unit_table and unit_table.isangle then
				uncU = uncU .. unit_table.text
				uncL = uncL .. unit_table.text
			end
			unc_text = '<span style="margin-left:0.3em;">' .. mSu(uncU, uncL) .. '</span>'
		else
			-- Look for parentheses surrounding upper uncertainty
			paren_uncertainty = (uncU:sub(1, 1) == '(' and uncU:sub(-1) == ')')
			if paren_uncertainty then
				unc_text = '(' .. delimit(uncU:sub(2, -2), fmt) .. ')'
			else
				unc_text = '<span style="margin-left:0.3em;margin-right:0.15em">±</span>' .. delimit(uncU, fmt) .. '</span>'
			end
			if uncertainty.errend then
				unc_text = unc_text .. uncertainty.errend
			end
			if unit_table and unit_table.isangle then
				unc_text = unc_text .. unit_table.text
			end
		end
	end
	local e_text, n_text
	if number.n then
		n_text = delimit(number.n, fmt) .. (number.nend  or '')
		if not paren_uncertainty and unit_table and unit_table.isangle then
			n_text = n_text .. unit_table.text
		end
	else
		n_text = ''
		e_10 = e_10 or '0'
	end
	if e_10 then
		e_text = '10<sup>' .. delimit(e_10) .. '</sup>'
		if number.n then
			e_text = '<span style="margin-left:0.25em;margin-right:0.15em">×</span>' .. e_text
		end
	else
		e_text = ''
	end
	return table.concat({
			'<span class="nowrap">',
			misc_tbl.prefix or '',
			paren_wrap and '(' or '',
			n_text,
			unc_text or '',
			paren_wrap and ')' or '',
			e_text,
			(unit_table and not unit_table.isangle) and unit_table.text or '',
			misc_tbl.suffix or '',
			'</span>'
		})
end

local function main(frame)
	if not getArgs then
		getArgs = require('Module:Arguments').getArgs
	end
	local args = getArgs(frame, {wrappers = { 'Template:Val', 'Template:Val/sandboxlua' }})
	local number = {n=args[1], nend=args['end']}
	local nocat = args.nocategory

	-- Error checking
	if args[1] and not validnumber(args[1]) then
		return valerror('first argument is not a valid number.',nocat)
	end
	if args[2] and not validnumber(args[2]) then
		return valerror('second argument is not a valid number.',nocat)
	end
	if args[3] and not validnumber(args[3]) then
		return valerror('third argument is not a valid number.',nocat)
	end
	if args.e and not validnumber(args.e) then
		return valerror('exponent argument (<b>e</b>) is not a valid number.',nocat)
	end
	if args.u and args.ul then
		return valerror('unit (<b>u</b>) and unit with link (<b>ul</b>) are both specified, only one is allowed.',nocat)
	end
	if args.up and args.upl then
		return valerror('unit per (<b>up</b>) and unit per with link (<b>upl</b>) are both specified, only one is allowed.',nocat)
	end

	-- Group arguments into related categories and unpack when needed
	local uncertainty = {
			upper = args[2],
			lower = args[3],
			errend = args.errend,
			upperend = args['+errend'],
			lowerend = args['-errend'],
		}
	local unit_spec = {
			u = args.ul or args.u,
			link = args.ul ~= nil,
			per = args.upl or args.up,
			per_link = args.upl ~= nil,
		}
	local misc_tbl = {
			e = args.e,
			prefix = args.p,
			suffix = args.s,
			fmt = args.fmt or '',
			nocat = args.nocategory,
		}
	return _main(number, uncertainty, unit_spec, misc_tbl)
end

return { main = main, _main = _main }