Module:Convert

-- TODO Too many items to list, but following are some points: - Output needs  rather than space in several places. - Some conversions require two outputs: 55 nmi. - Some units have two values: 3.21 m. - Remove commas from input numbers; add to output (always?). - Use U+2212 MINUS SIGN for input + output number, not '-'. - Should we support the nonexistent °K (it's just K)? --

---BEGIN DATA TABLE- Plan to write a program to generate the conversion tables below. The input would be a text file in human-friendly format, and the output would be the following tables. When a lot of data is added, it might be useful to put this in another module. Values from http://en.wikipedia.org/wiki/Conversion_of_units Check with http://en.wikipedia.org/wiki/Template:Convert/list_of_units --

local SIprefixes = { ['Y'] = { exponent = 24, name = 'yotta' }, ['Z'] = { exponent = 21, name = 'zetta' }, ['E'] = { exponent = 18, name = 'exa'  }, ['P'] = { exponent = 15, name = 'peta' }, ['T'] = { exponent = 12, name = 'tera' }, ['G'] = { exponent = 9, name = 'giga'  }, ['M'] = { exponent = 6, name = 'mega'  }, ['k'] = { exponent = 3, name = 'kilo'  }, ['H'] = { exponent = 2, name = 'hecto' },  -- not an SI prefix, but allow for people typing this ['h'] = { exponent = 2, name = 'hecto' }, ['da']= { exponent = 1, name = 'deca'  }, ['D'] = { exponent = 1, name = 'deca'  },  -- not an SI prefix, but allow for people typing this ['d'] = { exponent = -1, name = 'deci' }, ['c'] = { exponent = -2, name = 'centi' }, ['m'] = { exponent = -3, name = 'milli' }, ['µ'] = { exponent = -6, name = 'micro' }, ['u'] = { exponent = -6, name = 'micro' }, -- not an SI prefix, but allow for people typing this ['n'] = { exponent = -9, name = 'nano' }, ['p'] = { exponent =-12, name = 'pico' }, ['f'] = { exponent =-15, name = 'femto' }, ['a'] = { exponent =-18, name = 'atto' }, ['z'] = { exponent =-21, name = 'zepto' }, ['y'] = { exponent =-24, name = 'yocto' }, }

-- This is a first try at a names table using tricks to calculate missing values. -- I (Johnuniq) will try this for a while, but my instinct is telling me that it -- would be better to just fill in all values for each unit, and have no calculations. -- To that, I might try my plan of generating such a table using a script with code -- like the following. It would create the required table reading input from a -- human-friendly text file. -- I haven't bothered aligning columns because of my above plans. local unitnames = { -- Table to lookup names/symbols for a unit. -- Example entry with all possible fields: --     ['unit code'] = { --         name1    = 'singular name', --         name1_us = 'singular name sp=us',   -- (optional) --         name2    = 'plural name',           -- (optional) --         name2_us = 'plural name sp=us',     -- (optional) --         symbol   = 'symbol', --         sym_us   = 'symbol sp=us'           -- (optional) --     }    -- Optional items are calculated if needed (on first access). lookup = function (self, unit, prefixname) -- Return table with name and symbol for given unit. -- TODO FIX bad code for handling SI prefixes: --     This modifies the table for the entry that is returned. --     Caller must use the table before accessing the same table with a different prefix! --     For example: 5 km fouls up. local mt = { __index = function (self, key) local value = rawget(self, key) if value == nil then assert(key ~= 'name1', 'Bug: names table is missing name1') assert(key ~= 'symbol', 'Bug: names table is missing symbol') if key == 'name1_us' then -- Also set plural US name because that is hard to do later. value = rawget(self, 'name1') self['name2_us'] = self['name2'] elseif key == 'sym_us' then value = rawget(self, 'symbol') elseif key == 'name2' then value = rawget(self, 'name1') .. 's'                   elseif key == 'name2_us' then value = rawget(self, 'name1_us') if value == nil then value = self['name2'] else value = value .. 's'                       end else assert(key ~= nil, 'Bug: undex is nil') assert(false, 'Bug: unknown index ' .. key) end rawset(self, key, value) end if key:sub(1, 4) == 'name' then value = self.prefixname .. value end return value end }       local t = self[unit] assert(t ~= nil, 'Bug: names table has no entry for ' .. (unit or 'nil')) t.prefixname = prefixname or '' return setmetatable(t, mt) end, ['g']    = { name1 = 'gram', symbol = 'g' }, ['lb']   = { name1 = 'pound', symbol = 'lb' }, ['oz']   = { name1 = 'ounce', symbol = 'oz' }, ['ozt']  = { name1 = 'troy ounce', symbol = 'ozt' }, ['m']    = { name1 = 'metre', name1_us = 'meter', symbol = 'm' }, ['mi']   = { name1 = 'mile', symbol = 'mi' }, ['ft']   = { name1 = 'foot', name2 = 'feet', symbol = 'ft' }, ['yd']   = { name1 = 'yard', symbol = 'yd' }, ['in']   = { name1 = 'inch', name2 = 'inches', symbol = 'in' }, ['K']    = { name1 = 'kelvin', symbol = 'K' }, ['C']    = { name1 = 'degree Celsius', name2 = 'degrees Celsius', symbol = '°C' }, ['F']    = { name1 = 'degree Fahrenheit', name2 = 'degrees Fahrenheit', symbol = '°F' }, ['m2']   = { name1 = 'square metre', name1_us = 'square meter', symbol = 'm2' }, ['a']    = { name1 = 'are', symbol = 'a' }, ['sqft'] = { name1 = 'square foot', name2 = 'square feet', symbol = 'sq ft' }, ['sqyd'] = { name1 = 'square yard', symbol = 'sq yd' }, ['acre'] = { name1 = 'acre', symbol = 'acre' }, ['m3']   = { name1 = 'cubic metre', name1_us = 'cubic meter', symbol = 'm3' }, ['l']    = { name1 = 'litre', name1_us = 'liter', symbol = 'l' }, ['L']    = { name1 = 'litre', name1_us = 'liter', symbol = 'L' }, ['cuyd'] = { name1 = 'cubic yard', symbol = 'cu yd' }, ['USgal'] = { name1 = 'US gallon', name1_us = 'U.S. gallon', symbol = 'US gal', sym_us = 'U.S. gal' }, ['USoz'] = { name1 = 'US fluid ounce', name1_us = 'U.S. fluid ounce', symbol = 'US fl oz', sym_us = 'U.S. fl oz' }, ['USpt'] = { name1 = 'US pint', name1 = 'U.S. pint', symbol = 'US pt' }, ['impgal']= { name1 = 'imperial gallon', symbol = 'imp gal' }, ['impoz'] = { name1 = 'imperial fluid ounce', symbol = 'imp fl oz' }, ['imppt'] = { name1 = 'imperial pint', symbol = 'imp pt' }, ['km2']  = { name1 = 'square kilometre', name1_us = 'square kilometer', symbol = 'km2' }, ['km3']  = { name1 = 'cubic kilometre', name1_us = 'cubic kilometer', symbol = 'km3' }, ['USbbl'] = { name1 = 'US barrel', name1_us = 'U.S. barrel', symbol = 'US bbl', sym_us = 'U.S. bbl' }, } -- Aliases. unitnames['°K'] = unitnames['K'] unitnames['°C'] = unitnames['C'] unitnames['°F'] = unitnames['F']

local units = { lookup = function (self, unit) -- Return true, t where t is the unit's converter table (or false, message). -- Given 'unit' is a symbol (like 'g'), with an optional SI prefix (as in 'kg'). -- If, for example, 'kg' is in this table, that entry is used; otherwise prefix is applied. local t = self[unit] if t ~= nil then return true, { utype = t.utype, scale = t.scale, offset = t.offset, baseunit = unit, prefix = "", names = unitnames:lookup(unit) } end for plen = 2, 1, -1 do           -- Check for longer prefix first ('dam' is decametre). local prefix = string.sub(unit, 1, plen) local si = SIprefixes[prefix] if si ~= nil then local baseunit = unit:sub(plen+1) local t = self[baseunit] if t ~= nil and t.prefixes == true then return true, { utype = t.utype, scale = t.scale * 10^si.exponent, offset = t.offset, baseunit = baseunit, prefix = prefix, names = unitnames:lookup(baseunit, si.name) } end end end local msg = 'Unit %s is not known.' return false, msg:format(unit) end, -- The scales and offsets for mass convert to kilogramme as the intermediary unit. ['g'] =  { utype = 'mass',         scale = 0.001,          offset = 0,             prefixes = true}, ['lb'] = { utype = 'mass',         scale = 0.45359237,     offset = 0,             }, ['oz'] = { utype = 'mass',         scale = 0.45359237/16,  offset = 0,             }, ['ozt'] = { utype = 'mass',        scale = 0.0311034768,   offset = 0,             }, -- The scales and offsets for length convert to metre as the intermediary unit. ['m'] =  { utype = 'length',       scale = 1,              offset = 0,             prefixes = true}, ['mi'] = { utype = 'length',       scale = 1609.344,       offset = 0,             }, ['ft'] = { utype = 'length',       scale = 0.3048,         offset = 0,             }, ['yd'] = { utype = 'length',       scale = 0.3048 * 3,     offset = 0,             }, ['in'] = { utype = 'length',       scale = 0.0254,         offset = 0,             }, -- The scales and offsets for temperature convert to Kelvin as the intermediary unit. ['K'] =  { utype = 'temperature',  scale = 1,              offset = 0,             }, ['C'] =  { utype = 'temperature',  scale = 1,              offset = -273.15,       }, ['F'] =  { utype = 'temperature',  scale = 5/9,            offset = 32-273.15*(9/5),}, -- The scales and offsets for area convert to square metre as the intermediary unit. ['m2'] = { utype = 'area',         scale = 1,              offset = 0,             }, ['a'] =  { utype = 'area',         scale = 100,            offset = 0,             prefixes = true}, ['sqft'] ={ utype = 'area',        scale = 0.09290304,     offset = 0,             }, ['sqyd'] ={ utype = 'area',        scale = 0.83612736,     offset = 0,             }, ['acre'] ={ utype = 'area',        scale = 4046.8564224,   offset = 0,             }, -- The scales and offsets for volume convert to cubic metre as the intermediary unit. ['m3'] = { utype = 'volume',       scale = 1,              offset = 0,             }, ['l'] =  { utype = 'volume',       scale = 0.001,          offset = 0,             prefixes = true}, ['L'] =  { utype = 'volume',       scale = 0.001,          offset = 0,             prefixes = true}, ['cuyd'] ={ utype = 'volume',      scale = 0.764554857984, offset = 0,             }, ['USgal']={ utype = 'volume',      scale = 0.003785411784, offset = 0,             }, ['USoz'] ={ utype = 'volume',      scale = 0.003785411784/128, offset = 0,         }, ['USpt'] ={ utype = 'volume',      scale = 0.003785411784/8, offset = 0,           }, ['impgal']={ utype = 'volume',     scale = 0.00454609,     offset = 0,             }, ['impoz']={ utype = 'volume',      scale = 0.00454609/160, offset = 0,             }, ['imppt']={ utype = 'volume',      scale = 0.00454609/8,   offset = 0,             }, } -- Aliases. units['°K'] = units['K'] units['°C'] = units['C'] units['°F'] = units['F']

local defaultunits = { lookup = function (self, unit_table) -- Return true, s where s = name of unit's default output unit (or false, message). local baseunit = unit_table.baseunit local prefix = unit_table.prefix local unit = prefix .. baseunit local t = self[unit] if t ~= nil then return true, t[1] end t = self[baseunit] if t ~= nil and t.prefixes == true then local defaultunit = t[prefix] or t[1] return true, defaultunit end local msg = 'Unit %s has no default target conversion.' return false, msg:format(unit) end, -- Non-metric units default to one metric equivalent. ['ft'] = { 'm' }, ['yd'] = { 'm' }, ['in'] = { 'cm' }, ['lb'] = { 'kg' }, ['oz'] = { 'g' }, ['ozt'] = { 'g' }, ['mi'] = { 'km' }, ['F'] =  { 'C' }, ['°F'] = { '°C' }, ['sqft'] ={ 'm2' }, ['sqyd'] ={ 'm2' }, ['sqmi'] ={ 'km2' }, ['USgal']={ 'L' }, ['USoz'] ={ 'cL' }, ['USpt'] ={ 'dL' }, ['impgal']={ 'L' }, ['impoz']={ 'cL' }, ['imppt']={ 'dL' }, -- Metric units default to various non-metric units, according to SI prefix. ['g'] =  { 'oz',     prefixes = true,  k = 'lb', M = 'lb', G = 'lb' }, ['m'] =  { 'ft',     prefixes = true,  p = 'in', n = 'in', u = 'in', m = 'in', c = 'in', d = 'in', da = 'yd', H = 'yd', k = 'mi' }, ['K'] =  { 'C' }, ['C'] =  { 'F' }, ['°K'] = { '°C' }, ['°C'] = { '°F' }, ['m2'] = { 'sqyd' }, ['a'] =  { 'acre',   prefixes = true}, ['m3'] = { 'cuyd' }, ['L'] =  { 'imppt',   prefixes = true, m = 'impoz', c = 'impoz', d = 'impoz', da = 'impgal', H = 'impgal'}, }

---END DATA TABLE-

-- Configuration options to keep magic values in one location. local config = {}

local function get_config(frame) -- Return table of configuration options. -- Unclear if this is currently needed, but it may help if adapting -- code for a different wiki. local cfg = {} -- Following settings are defaults that can be overridden by template. cfg.numdot = '.'       -- decimal mark before fractional digits cfg.numsep = ','       -- thousands separator for numbers (',', '.', or nil) for k,v in frame:argumentPairs do       cfg[k] = v          -- arguments from template's     end -- Following settings are mandatory (to limit abuse). cfg.maxsigfig = 20     -- maximum number of significant figures return cfg end

local function withseparator(text) -- Return string for a number with thousand separators inserted. -- Parameter text is a string like "-12345" or "12345.6789". -- Separator is inserted only in the integer part (not in fraction). -- Four-digit integer parts have a separator (like "1,234"). local numsep = config.numsep if #numsep == 0 then return text end local function insert(text, first, last) local result = '' while last >= first do           if last >= first + 3 then result = numsep .. text:sub(last-2, last) .. result last = last - 3 else return text:sub(first, last) .. result end end return result end local first = 1 local sign = text:sub(first, 1) if sign == '+' or sign == '-' then -- To handle Unicode minus (multibyte), perhaps use following: -- first = text:find('%d') first = 2 else sign = '' end local last = text:find(config.numdot, first, true) if last == nil then last = #text else last = last - 1 end return sign .. insert(text, first, last) .. text:sub(last+1) end

local function formatnumber(value, sigfig) -- Return result of converting number 'value' to a string, -- rounded to 'sigfig' significant figures. local format = string.format local rep = string.rep local sign = '' local numdot = config.numdot local function zeropad(text, dot) count = sigfig - #text if count <= 0 then return text end return text .. dot .. rep('0', count) end if sigfig <= 0 then sigfig = 1 elseif sigfig > config.maxsigfig then sigfig = config.maxsigfig end if value == 0 then return zeropad('0', numdot) end if value < 0 then sign = '-' -- need proper Unicode minus value = -value end local digits local exp, frac = math.modf(math.log10(value)) if frac == 0 then -- Value 1 gives frac = 0, and 0.1 gives frac = -0 (negative zero). -- Both results give true in 'if frac == 0'. digits = zeropad('1', '') exp = exp + 1 -- adjust so dot is before digits else local prec = sigfig if value > 1 then prec = prec - 1 -- will be one sig fig before dot end digits = format(format('%%.%df', prec), 10^frac) if value < 1 then -- Is MediaWiki run in a locale where following might be '0,'? assert(digits:sub(1, 2) == '0.', 'Bug: rounded number not 0.xxx') digits = digits:sub(3) else if prec == 0 then assert(digits:find(numdot, 1, true) == nil, 'Bug: unexpected dot') else assert(digits:sub(2, 2) == numdot, 'Bug: rounded number not x.xxx') digits = digits:sub(1, 1) .. digits:sub(3) end exp = exp + 1 -- adjust so dot is before digits end end if exp >= #digits then digits = digits .. rep('0', exp - #digits) -- result has no dot elseif exp <= 0 then digits = '0' .. numdot .. rep('0', -exp) .. digits else digits = digits:sub(1, exp) .. numdot .. digits:sub(exp+1) end return sign .. digits end

local function require_number(value, missing, invalid) -- Return true, n where n = number equivalent to given value (or false, message). -- Thousand separators (valid or not) are first removed. if value == nil then return false, missing end if type(value) == 'number' then return true, value end local numsep = config.numsep if #numsep > 0 then value = string.gsub(value, numsep, '') end local number = tonumber(value) if number == nil then return false, invalid:format(value) end return true, number end

local function require_integer(value, missing, invalid) -- Return true, n where n = integer equivalent to given value (or false, message). local success, number = require_number(value, missing, invalid) if not success then return success, number end if number ~= math.floor(number) then return false, invalid:format(value) end return true, number end

local function get_parms(pframe) -- Return true, t where t is a table with all arguments passed to the template -- converted to named arguments. The numeric args are used to add named args: --  in_text, in_text2 (strings given for value, value2) --  value, in_unit, out_unit, value2, range, round_to -- (except for range, which is nil or a table, the named args that are   -- added here could be provided by the user of the template). local range_types = { -- text to separate input, output ranges ['and'] = {' and ', ' and '}, ['by'] = {' by ', ' by '}, ['to'] = {' to ', ' to '}, ['-'] = {'–', '–'},       ['to(-)'] = {' to ', '–'}, ['x'] = {' by ', ' × '}, ['+/-'] = {' ± ', ' ± '},   }    local success, t    local args = {}                         -- arguments passed to template for k,v in pframe:argumentPairs do       args[k] = v    end args.in_text = args[1] success, t = require_number(args.in_text, 'Need value', 'Value "%s" must be a number') if not success then return success, t else args.value = t end local in_unit = args[2] local i = 3 local range = range_types[in_unit] if range ~= nil then args.in_text2 = args[3] success, t = require_number(args.in_text2, 'Need second value', 'Second value "%s" must be a number') if not success then return success, t else args.value2 = t end in_unit = args[4] i = 5 end local out_unit = args[i] local round_to = args[i+1] if in_unit == nil then return false, 'Need input unit' end args.in_unit = in_unit args.out_unit = out_unit args.range = range args.round_to = args.round_to or round_to -- allow named parameter return true, args end

local function default_roundto(intext, factor) -- Return a default value for round_to (an integer like 2, 0, -2). -- prec = (precision implied in intext) --     = (#digits after dot, or negative of #zeroes before dot) -- If conversion is multiplication by a factor, and -- if factor >= 0.02, compensate prec by adding N where: --    N    factor is in range --    1     .02  :   .2   =    .1/5 :   .1*2    --     0     .2   :   2    =    1/5  :   1*2    --    -1     2    :  20    =   10/5  :  10*2    --    -2    20    : 200    =  100/5  : 100*2  etc. -- TODO Exception required for temperature. prec = 0 dot = intext:find('.', 1, true) if dot ~= nil then prec = intext:sub(dot+1):len if prec == 0 then intext = intext:sub(1, -2) end end if prec == 0 then prec = -intext:match('0*$'):len end if factor ~= nil and factor >= 0.02 then prec = prec - math.floor(math.log10(factor*5)) end return prec end

local function scaled(value, in_unit, out_unit) -- Return scaled value for a simple convert. return (value - in_unit.offset) * (in_unit.scale / out_unit.scale) + out_unit.offset end

local function cvtround(invalue, intext, parms) -- Return true, s where s = rounded, formatted string from converting invalue, -- using the rounding specified in parms (s = '' if invalue == nil). -- This code combines convert/round because some rounding requires -- knowledge of what we are converting. -- TODO Lots of checking required. Will need tweaks for special cases -- handled by old Template:Convert. -- TODO Limit values to avoid abuse (for example, can currently set   -- round_to to very large values like 999). local text = '' if invalue == nil then return true, text end local outvalue = scaled(invalue, parms.in_unit_table, parms.out_unit_table) local round_to = parms.round_to local sigfig = parms.sigfig local disp = parms.disp local auto = false if round_to then -- Ignore sigfig, disp. success, round_to = require_integer(round_to, 'Need value', 'round_to "%s" must be an integer') if not success then return success, round_to end elseif sigfig then -- Ignore disp. success, sigfig = require_integer(sigfig, 'Need value', 'sigfig "%s" must be an integer') if not success then return success, sigfig end if sigfig <= 0 then msg = 'sigfig "%s" must be positive' return false, msg:format(parms.sigfig) end text = formatnumber(outvalue, sigfig) elseif disp == '5' then local negative = false if outvalue < 0 then negative = true outvalue = -outvalue end outvalue = math.floor((outvalue / 5) + 0.5) * 5 if negative then outvalue = -outvalue end text = string.format('%.0f', outvalue) else auto = true -- using default rounding -- TODO If conversion is not multiplication by a number, need factor = nil. local factor = outvalue / invalue round_to = default_roundto(intext, factor) end if round_to then if round_to >= 0 then if auto then -- TODO No less than two significant figures. end -- It seems format('%d', x) uses modf to extract integer from x           -- with result '0' if x is 0 or -0 (negative zero). -- Using format('%.0f', x) gives '-0' if x is negative zero. local fmt = '%.' .. string.format('%d', round_to) .. 'f'           text = string.format(fmt, outvalue) else -- This always keeps two sig figs. Should that be done if not auto? round_to = -round_to -- #digits that want to zero local maxzeroes = 0 -- maximum #digits that should be zeroed if outvalue > 100 then maxzeroes = math.modf(math.log10(outvalue)) - 1 end if round_to > maxzeroes then round_to = maxzeroes end if round_to > 0 then local scaled = string.format('%.0f', outvalue/(10^round_to)) text = scaled .. string.rep('0', round_to) else text = formatnumber(outvalue, 2) -- can't zero digits; keep 2 sig figs end end end return true, withseparator(text) end

local disp_single = { ['or'] = '%s %s or %s %s', ['sqbr'] = '%s %s [%s %s]', ['comma'] = '%s %s, %s %s', ['slash'] = '%s %s / %s %s', ['s'] = '%s %s / %s %s', ['b'] = '%s %s (%s %s)', }

local disp_double = { ['or'] = '%s%s%s %s or %s%s%s %s', ['sqbr'] = '%s%s%s %s [%s%s%s %s]', ['comma'] = '%s%s%s %s, %s%s%s %s', ['slash'] = '%s%s%s %s / %s%s%s %s', ['s'] = '%s%s%s %s / %s%s%s %s', ['b'] = '%s%s%s %s (%s%s%s %s)', }

local function process(parms) -- Return true, s where s = final wikitext result (or false, message). local success, t   success, t = units:lookup(parms.in_unit) if not success then return success, t else parms.in_unit_table = t end if parms.out_unit == nil then          -- need to catch empty string also? success, t = defaultunits:lookup(parms.in_unit_table) if not success then return success, t else parms.out_unit = t end end success, t = units:lookup(parms.out_unit) if not success then return success, t else parms.out_unit_table = t end if parms.in_unit_table.utype ~= parms.out_unit_table.utype then local msg = 'Cannot convert %s to %s.' return false, msg:format(parms.in_unit_table.utype, parms.out_unit_table.utype) end local intext1, outtext1 = parms.in_text, nil local intext2, outtext2 = parms.in_text2, nil success, outtext1 = cvtround(parms.value, intext1, parms) if not success then return success, outtext1 end success, outtext2 = cvtround(parms.value2, intext2, parms) if not success then return success, outtext2 end local range = parms.range local disp = parms.disp local wikitext intext1 = withseparator(intext1) -- TODO what if intext1 already has commas? -   -- TODO Clean up following (a first try at using proper names/symbols). local inkey, outkey, symkey = 'name2', 'name2', 'symbol' if parms.value == 1 then inkey = 'name1' end local outvalue = 2    -- dummy value if outvalue == 1 then -- TODO need to know if value from cvtround needs singular or plural name outkey = 'name1' end if parms.sp == 'us' then inkey = inkey .. '_us' outkey = outkey .. '_us' symkey = 'sym_us' end local in_name = parms.in_unit_table.names[inkey]      -- will not need to calculate all of these local in_symbol = parms.in_unit_table.names[symkey] local out_name = parms.out_unit_table.names[outkey] local out_symbol = parms.out_unit_table.names[symkey] local abbr = parms.abbr local in_id, out_id if abbr == 'on' then           -- all symbols in_id = in_symbol out_id = out_symbol elseif abbr == 'off' then      -- all names in_id = in_name out_id = out_name elseif abbr == 'in' then       -- input symbols in_id = in_symbol out_id = out_symbol elseif abbr == 'out' then      -- output symbols [is this just the default?] in_id = in_name out_id = out_symbol elseif abbr == 'values' then   -- show only values -- LATER elseif abbr == 'mos' then      -- for ranges, abbreviate with input unit repeated -- LATER else                           -- default in_id = in_name out_id = out_symbol end if range == nil then if disp == 'output only' then wikitext = '%s %s' wikitext = wikitext:format(outtext1, out_id) elseif disp == 'output number only' or disp == 'number' then wikitext = outtext1 elseif disp == 'unit' then wikitext = in_id elseif disp == 'unit2' then wikitext = out_id elseif disp == 'flip' then wikitext = disp_single['b'] wikitext = wikitext:format(outtext1, out_id, intext1, in_id) else wikitext = disp_single[disp] or disp_single['b'] wikitext = wikitext:format(intext1, in_id, outtext1, out_id) end else -- TODO Need in_id, out_id (and more) here. wikitext = disp_double[disp] or disp_double['b'] wikitext = wikitext:format(intext1, range[1], intext2, in_id, outtext1, range[2], outtext2, out_id) end -   return true, wikitext end

-- Used by template. -- We will have to keep old undefined undefined for a long time, and run -- in parallel with undefined undefined while testing/developing. local p = {} local bodge = require "Module:mw" -- This fixes up mw.text.tag for us.

function p.convert(frame) config = get_config(frame) local pframe = frame:getParent local parms, text success, parms = get_parms(pframe) if success then success, text = process(parms) end if not success then local params = {style="color:black; background-color:orange;"} text=mw.text.tag({name="span", contents="Conversion error: " .. text, params=params}) end return text end

return p