result.sortkey = convert_unit.sortspan
if use_convert then
result.text = convert_unit.text
result.scaled_top = convert_unit.scaled_value
else
if want_link then
result.text = * .. result.symbol .. *
else
result.text = result.symbol
end
result.scaled_top = value
end
return result
end  
local function makeunit(value, options)
-- Return table of information for the requested unit and options, or
-- return nil if no unit.
options = options or {}
local unit
local ucode = options.u
local percode = options.per
if ucode then
unit = get_unit(ucode, value, nil, options)
elseif percode then
unit = { nospace = true, scaled_top = value }
else
return nil
end
local text = unit.text or ''
local sortkey = unit.sortkey
if percode then
local function bracketed(code, text)
return code:find('[*./]') and '(' .. text .. ')' or text
end
local perunit = get_unit(percode, 1, unit.scaled_top, options)
text = (ucode and bracketed(ucode, text) or '') ..
'/' .. bracketed(percode, perunit.text)
sortkey = perunit.sortkey
end
if not (unit.nospace or options.nospace) then
text = '&nbsp;' .. text
end
return { text = text, isangle = unit.isangle, sortkey = sortkey }
end  
local function list_units(mode)
-- Return wikitext to list the built-in units.
-- A unit code should not contain wikimarkup so don't bother escaping.
local data = mw.loadData(data_module)
local definitions = data.builtin_units .. data.builtin_units_long_scale
local last_was_blank = true
local n = 0
local result = {}
local function add(line)
if line == '' then
last_was_blank = true
else
if last_was_blank and n > 0 then
n = n + 1
result[n] = ''
end
last_was_blank = false
n = n + 1
result[n] = line
end
end
local si_prefixes = {
-- These are the prefixes recognized by convert; u is accepted for micro.
y = 'y',
z = 'z',
a = 'a',
f = 'f',
p = 'p',
n = 'n',
u = 'µ',
['µ'] = 'µ',
m = 'm',
c = 'c',
d = 'd',
da = 'da',
h = 'h',
k = 'k',
M = 'M',
G = 'G',
T = 'T',
P = 'P',
E = 'E',
Z = 'Z',
Y = 'Y',
}
local function is_valid(ucode, unit)
if unit and not unit.more_ignored then
assert(type(unit.symbol) == 'string' and unit.symbol ~= '')
if unit.alias then
if unit.link or unit.scale_text or unit.si then
return false
end
end
if unit.si then
if unit.scale_text then
return false
end
ucode = unit.ucode or ucode
local base = unit.symbol
if ucode == base then
unit.display = base
return true
end
local plen = #ucode - #base
if plen > 0 then
local prefix = si_prefixes[ucode:sub(1, plen)]
if prefix and ucode:sub(plen + 1) == base then
unit.display = prefix .. base
return true
end
end
else
unit.display = unit.symbol
return true
end
end
return false
end
local lookup = require(convert_module)._unit
local function show_convert(ucode, unit)
-- If a built-in unit defines a scale or sets the SI flag, any unit defined in
-- convert is not used (the scale or SI prefix's scale is used for a sort key).
-- If there is no scale or SI flag, and the unit is not defined in convert,
-- the sort key may not be correct; this allows such units to be identified.
if not (unit.si or unit.scale_text) then
if mode == 'convert' then
unit.show = not lookup(unit.alias and unit.symbol or ucode).unknown
unit.show_text = 'CONVERT'
elseif mode == 'unknown' then
unit.show = lookup(unit.alias and unit.symbol or ucode).unknown
unit.show_text = 'UNKNOWN'
elseif not unit.alias then
-- Show convert's scale in square brackets ('[1]' for an unknown unit).
-- Don't show scale for an alias because it's misleading for temperature
-- and an alias is probably not useful for anything else.
local scale = lookup(ucode, {value=1, sort='on'}).scaled_value
if type(scale) == 'number' then
scale = string.format('%.5g', scale):gsub('e%+?(%-?)0*(%d+)', 'e%1%2')
else
scale = '?'
end
unit.show = true
unit.show_text = '[' .. scale .. ']'
end
end
end
for line in definitions:gmatch('([^\n]*)\n') do
local pos, _ = line:find(' ', 1, true)
if pos then
local ucode = line:sub(1, pos - 1)
local unit = get_builtin_unit(ucode, '\n' .. line .. '\n')
if is_valid(ucode, unit) then
show_convert(ucode, unit)
local flags, text
if unit.alias then
text = unit.symbol
else
text = * .. unit.display .. *
end
if unit.isangle then
unit.nospace = nil -- don't show redundant flag
end
for _, f in ipairs({
{ 'alias', 'ALIAS' },
{ 'isangle', 'ANGLE' },
{ 'nospace', 'NOSPACE' },
{ 'si', 'SI' },
{ 'scale_text', unit.scale_text },
{ 'show', unit.show_text },
}) do
if unit[f[1]] then
local t = f[2]
if t:match('^%u+$') then
t = '<small>' .. t .. '</small>'
end
if flags then
flags = flags .. ' ' .. t
else
flags = t
end
end
end
if flags then
text = text .. ' • ' .. flags
end
add(ucode .. ' = ' .. text .. '
')
else
add(line .. ' ◆ <b>invalid definition</b>
')
end
else
add(line)
end
end
return table.concat(result, '\n')
end  
local delimit_groups = require('Module:Gapnum').groups
local function delimit(sign, numstr, fmt)
-- Return sign and numstr (unsigned digits or '.' only) after formatting.
-- Four-digit integers are not formatted with gaps.
fmt = (fmt or ''):lower
if fmt == * or (fmt == * and #numstr == 4 and numstr:match('^%d+$')) then
return sign .. numstr
end
-- Group number by integer and decimal parts.
-- If there is no decimal part, delimit_groups returns only one table.
local ipart, dpart = delimit_groups(numstr)
local result
if fmt == 'commas' then
result = sign .. table.concat(ipart, ',')
if dpart then
result = result .. '.' .. table.concat(dpart)
end
else
-- Delimit with a small gap by default.
local groups = {}
groups[1] = table.remove(ipart, 1)
for _, v in ipairs(ipart) do
table.insert(groups, '<span>' .. v .. '</span>')
end
if dpart then
table.insert(groups, '.' .. (table.remove(dpart, 1) or ''))
for _, v in ipairs(dpart) do
table.insert(groups, '<span>' .. v .. '</span>')
end
end
result = sign .. table.concat(groups)
end
return result
end  
local function sup_sub(sup, sub, align)
-- Return the same result as Module:Su except val defaults to align=.
if align == 'l' or align == '' then
elseif align == 'c' or align == '' then
else
end
return '<span>' .. sup .. '
' .. sub .. '</span>'
end  
local function range_text(items, unit_table, options)
local fmt = options.fmt
local nend = items.nend or ''
if items.isrepeat or unit_table.isangle then
nend = nend .. unit_table.text
end
local text = ''
for i = 1, #items do
if i % 2 == 0 then
text = text .. items[i]
else
text = text .. delimit(items[i].sign, items[i].clean, fmt) .. nend
end
end
return text
end  
local function uncertainty_text(uncertainty, unit_table, options)
local angle, text, need_parens
if unit_table.isangle then
angle = unit_table.text
end
local upper = uncertainty.upper or {}
local lower = uncertainty.lower or {}
local uncU = upper.clean
if uncU then
local fmt = options.fmt
local uncL = lower.clean
if uncL then
uncU = delimit('+', uncU, fmt) .. (upper.errend or '')
uncL = delimit('−', uncL, fmt) .. (lower.errend or '')
if angle then
uncU = uncU .. angle
uncL = uncL .. angle
end
text = (angle or '') ..
'<span>' ..
sup_sub(uncU, uncL, options.align) ..
'</span>'
else
if upper.parens then
text = '(' .. uncU .. ')' -- old template did not delimit
else
text = (angle or '') ..
'<span>±</span>' ..
delimit('', uncU, fmt)
need_parens = true
end
if uncertainty.errend then
text = text .. uncertainty.errend
end
if angle then
text = text .. angle
end
end
else
if angle then
text = angle
end
end
return text, need_parens
end  
local function _main(values, unit_spec, options)
if options.sandbox then
data_module = data_module .. '/sandbox'
convert_module = convert_module .. '/sandbox'
end
local action = options.action
if action then
if action == 'list' then
-- Kludge: am using the align parameter (a=xxx) for type of list.
return list_units(options.align)
end
return valerror('invalid action "' .. action .. '".', options.nocat)
end
local number = values.number or (values.numbers and values.numbers[1]) or {}
local e_10 = options.e or {}
local novalue = (number.value == nil and e_10.clean == nil)
local fmt = options.fmt
local want_sort = true
local sortable = options.sortable