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Permanently protected module
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local p = {}
-- Convert a value from one unit of measurement to another.
-- Example: {{convert|123|lb|kg}} --> 123 pounds (56 kg)
-- See [[:en:Template:Convert/Transwiki guide]] if copying to another wiki.


function p.factor(frame)
local MINUS = '−' -- Unicode U+2212 MINUS SIGN (UTF-8: e2 88 92)
-- Consider calling the parser function #expr
local abs = math.abs
-- to simplify a potential mathematical expression?
local floor = math.floor
number = tonumber(frame.args[1])
local format = string.format
if number == nil then
local log10 = math.log10
return '<strong class="error">Error: input not recognized as a number</strong>'
local ustring = mw.ustring
end
local ulen = ustring.len
local usub = ustring.sub


productSymbol = frame.args['product'] or '·'
-- Configuration options to keep magic values in one location.
bold = frame.args['bold'] and true
-- Conversion data and message text are defined in separate modules.
big = frame.args['big'] and true
local config, maxsigfig
serif = frame.args['serif'] and true
local numdot -- must be '.' or ',' or a character which works in a regex
primeLink = frame.args['prime'] and true
local numsep, numsep_remove, numsep_remove2
local data_code, all_units
local text_code
local varname -- can be a code to use variable names that depend on value
local from_en_table -- to translate an output string of en digits to local language
local to_en_table -- to translate an input string of digits in local language to en
-- Use translation_table in convert/text to change the following.
local en_default -- true uses lang=en unless convert has lang=local or local digits
local group_method = 3 -- code for how many digits are in a group
local per_word = 'per' -- for units like "liters per kilometer"
local plural_suffix = 's' -- only other useful value is probably '' to disable plural unit names
local omitsep -- true to omit separator before local symbol/name


number = math.floor(number)
-- All units should be defined in the data module. However, to cater for quick changes
if number < 2 or number > 1000000000 or number == math.huge then
-- and experiments, any unknown unit is looked up in an extra data module, if it exists.
return '<strong class="error">Error: ' .. number .. ' out of range</strong>'
-- That module would be transcluded in only a small number of pages, so there should be
end
-- little server overhead from making changes, and changes should propagate quickly.
local extra_module -- name of module with extra units
local extra_units -- nil or table of extra units from extra_module


result = ""
-- Some options in the invoking template can set variables used later in the module.
currentNumber = number
local currency_text -- for a user-defined currency symbol: {{convert|12|$/ha|$=€}} (euro replaces dollar)
power = 0
divisor = 2


-- Attempt factoring by the value of the divisor
local function from_en(text)
-- divisor increments by 2, except first iteration (2 to 3)
-- Input is a string representing a number in en digits with '.' decimal mark,
while divisor <= math.sqrt(currentNumber) do
-- without digit grouping (which is done just after calling this).
power = 0
-- Return the translation of the string with numdot and digits in local language.
while currentNumber % divisor == 0 do
if numdot ~= '.' then
currentNumber = currentNumber / divisor
text = text:gsub('%.', numdot)
power = power + 1
end
end
if from_en_table then
text = text:gsub('%d', from_en_table)
end
return text
end


-- Concat result and increment divisor
local function to_en(text)
-- when divisor is 2, go to 3. All other times, add 2
-- Input is a string representing a number in the local language with
result = result .. powerformat(divisor, power, productSymbol)
-- an optional numdot decimal mark and numsep digit grouping.
divisor = divisor + (divisor == 2 and 1 or 2)
-- Return the translation of the string with '.' mark and en digits,
end
-- and no separators (they have to be removed here to handle cases like
-- numsep = '.' and numdot = ',' with input "1.234.567,8").
if to_en_table then
text = ustring.gsub(text, '%d', to_en_table)
end
if numsep_remove then
text = text:gsub(numsep_remove, '')
end
if numsep_remove2 then
text = text:gsub(numsep_remove2, '')
end
if numdot ~= '.' then
text = text:gsub(numdot, '.')
end
return text
end


if currentNumber ~= 1 then
local function decimal_mark(text)
result = result .. currentNumber .. ' ' .. productSymbol .. ' '
-- Return ',' if text probably is using comma for decimal mark, or has no decimal mark.
end
-- Return '.' if text probably is using dot for decimal mark.
-- Otherwise return nothing (decimal mark not known).
if not text:find('[.,]') then return ',' end
text = text:gsub('^%-', ''):gsub('%+%d+/%d+$', ''):gsub('[Ee]%-?%d+$', '')
local decimal =
text:match('^0?([.,])%d+$') or
text:match('%d([.,])%d?%d?$') or
text:match('%d([.,])%d%d%d%d+$')
if decimal then return decimal end
if text:match('%.%d+%.') then return ',' end
if text:match('%,%d+,') then return '.' end
end


if currentNumber == number and primeLink then
local add_warning, with_separator -- forward declarations
return '[[prime number|prime]]'
local function to_en_with_check(text, parms)
end
-- Version of to_en() for a wiki using numdot = ',' and numsep = '.' to check
-- text (an input number as a string) which might have been copied from enwiki.
-- For example, in '1.234' the '.' could be a decimal mark or a group separator.
-- From viwiki.
if to_en_table then
text = ustring.gsub(text, '%d', to_en_table)
end
if decimal_mark(text) == '.' then
local original = text
text = text:gsub(',', '') -- for example, interpret "1,234.5" as an enwiki value
if parms then
add_warning(parms, 0, 'cvt_enwiki_num', original, with_separator({}, text))
end
else
if numsep_remove then
text = text:gsub(numsep_remove, '')
end
if numsep_remove2 then
text = text:gsub(numsep_remove2, '')
end
if numdot ~= '.' then
text = text:gsub(numdot, '.')
end
end
return text
end


result = string.sub(result,1,-4)
local function omit_separator(id)
-- Return true if there should be no separator before id (a unit symbol or name).
-- For zhwiki, there should be no separator if id uses local characters.
-- The following kludge should be a sufficient test.
if omitsep then
if id:sub(1, 2) == '-{' then -- for "-{...}-" content language variant
return true
end
if id:byte() > 127 then
local first = usub(id, 1, 1)
if first ~= 'Å' and first ~= '°' and first ~= 'µ' then
return true
end
end
end
return id:sub(1, 1) == '/' -- no separator before units like "/ha"
end


return format(result)
local spell_module -- name of module that can spell numbers
local speller -- function from that module to handle spelling (set if needed)
local wikidata_module, wikidata_data_module -- names of Wikidata modules
local wikidata_code, wikidata_data -- exported tables from those modules (set if needed)

local function set_config(args)
-- Set configuration options from template #invoke or defaults.
config = args
maxsigfig = config.maxsigfig or 14 -- maximum number of significant figures
local data_module, text_module
local sandbox = config.sandbox and ('/' .. config.sandbox) or ''
data_module = "Module:Convert/data" .. sandbox
text_module = "Module:Convert/text" .. sandbox
extra_module = "Module:Convert/extra" .. sandbox
wikidata_module = "Module:Convert/wikidata" .. sandbox
wikidata_data_module = "Module:Convert/wikidata/data" .. sandbox
spell_module = "Module:ConvertNumeric"
data_code = mw.loadData(data_module)
text_code = mw.loadData(text_module)
all_units = data_code.all_units
local translation = text_code.translation_table
if translation then
numdot = translation.numdot
numsep = translation.numsep
if numdot == ',' and numsep == '.' then
if text_code.all_messages.cvt_enwiki_num then
to_en = to_en_with_check
end
end
if translation.group then
group_method = translation.group
end
if translation.per_word then
per_word = translation.per_word
end
if translation.plural_suffix then
plural_suffix = translation.plural_suffix
end
varname = translation.varname
from_en_table = translation.from_en
local use_workaround = true
if use_workaround then
-- 2013-07-05 workaround bug by making a copy of the required table.
-- mw.ustring.gsub fails with a table (to_en_table) as the replacement,
-- if the table is accessed via mw.loadData.
local source = translation.to_en
if source then
to_en_table = {}
for k, v in pairs(source) do
to_en_table[k] = v
end
end
else
to_en_table = translation.to_en
end
if translation.lang == 'en default' then
en_default = true -- for hiwiki
end
omitsep = translation.omitsep -- for zhwiki
end
numdot = config.numdot or numdot or '.' -- decimal mark before fractional digits
numsep = config.numsep or numsep or ',' -- group separator for numbers
-- numsep should be ',' or '.' or '' or '&nbsp;' or a Unicode character.
-- numsep_remove must work in a regex to identify separators to be removed.
if numsep ~= '' then
numsep_remove = (numsep == '.') and '%.' or numsep
end
if numsep ~= ',' and numdot ~= ',' then
numsep_remove2 = ',' -- so numbers copied from enwiki will work
end
end
end


function powerformat(divisor, power, productSymbol)
local function collection()
if power < 1 then return ''
-- Return a table to hold items.
elseif power == 1 then return divisor .. ' ' .. productSymbol .. ' '
return {
else return divisor .. '<sup>' .. power .. '</sup>' .. productSymbol .. ' '
n = 0,
end
add = function (self, item)
self.n = self.n + 1
self[self.n] = item
end,
}
end
end


local function divide(numerator, denominator)
function format(numString)
if bold then
-- Return integers quotient, remainder resulting from dividing the two
numString = '<b>'..numString..'</b>'
-- given numbers, which should be unsigned integers.
end
local quotient, remainder = floor(numerator / denominator), numerator % denominator
if not (0 <= remainder and remainder < denominator) then
-- Floating point limits may need this, as in {{convert|160.02|Ym|ydftin}}.
remainder = 0
end
return quotient, remainder
end


ret = (serif or big) and '<span ' or ''
local function split(text, delimiter)
if serif then ret = ret .. 'class="texhtml" ' end
-- Return a numbered table with fields from splitting text.
if big then ret = ret .. 'style="font-size:165%" ' end
-- The delimiter is used in a regex without escaping (for example, '.' would fail).
ret = ret .. ((serif or big) and '>' or '') .. numString .. '</span>'
-- Each field has any leading/trailing whitespace removed.
local t = {}
text = text .. delimiter -- to get last item
for item in text:gmatch('%s*(.-)%s*' .. delimiter) do
table.insert(t, item)
end
return t
end

local function strip(text)
-- If text is a string, return its content with no leading/trailing
-- whitespace. Otherwise return nil (a nil argument gives a nil result).
if type(text) == 'string' then
return text:match("^%s*(.-)%s*$")
end
end

local function table_len(t)
-- Return length (<100) of a numbered table to replace #t which is
-- documented to not work if t is accessed via mw.loadData().
for i = 1, 100 do
if t[i] == nil then
return i - 1
end
end
end

local function wanted_category(catkey, catsort, want_warning)
-- Return message category if it is wanted in current namespace,
-- otherwise return ''.
local cat
local title = mw.title.getCurrentTitle()
if title then
local nsdefault = '0' -- default namespace: '0' = article; '0,10' = article and template
local namespace = title.namespace
for _, v in ipairs(split(config.nscat or nsdefault, ',')) do
if namespace == tonumber(v) then
cat = text_code.all_categories[want_warning and 'warning' or catkey]
if catsort and catsort ~= '' and cat:sub(-2) == ']]' then
cat = cat:sub(1, -3) .. '|' .. mw.text.nowiki(usub(catsort, 1, 20)) .. ']]'
end
break
end
end
end
return cat or ''
end

local function message(parms, mcode, is_warning)
-- Return wikitext for an error message, including category if specified
-- for the message type.
-- mcode = numbered table specifying the message:
-- mcode[1] = 'cvt_xxx' (string used as a key to get message info)
-- mcode[2] = 'parm1' (string to replace '$1' if any in message)
-- mcode[3] = 'parm2' (string to replace '$2' if any in message)
-- mcode[4] = 'parm3' (string to replace '$3' if any in message)
local msg
if type(mcode) == 'table' then
if mcode[1] == 'cvt_no_output' then
-- Some errors should cause convert to output an empty string,
-- for example, for an optional field in an infobox.
return ''
end
msg = text_code.all_messages[mcode[1]]
end
parms.have_problem = true
local function subparm(fmt, ...)
local rep = {}
for i, v in ipairs({...}) do
rep['$' .. i] = v
end
return (fmt:gsub('$%d+', rep))
end
if msg then
local parts = {}
local regex, replace = msg.regex, msg.replace
for i = 1, 3 do
local limit = 40
local s = mcode[i + 1]
if s then
if regex and replace then
s = s:gsub(regex, replace)
limit = nil -- allow long "should be" messages
end
-- Escape user input so it does not break the message.
-- To avoid tags (like {{convert|1<math>23</math>|m}}) breaking
-- the mouseover title, any strip marker starting with char(127) is
-- replaced with '...' (text not needing i18n).
local append
local pos = s:find(string.char(127), 1, true)
if pos then
append = '...'
s = s:sub(1, pos - 1)
end
if limit and ulen(s) > limit then
s = usub(s, 1, limit)
append = '...'
end
s = mw.text.nowiki(s) .. (append or '')
else
s = '?'
end
parts['$' .. i] = s
end
local function ispreview()
-- Return true if a prominent message should be shown.
if parms.test == 'preview' or parms.test == 'nopreview' then
-- For testing, can preview a real message or simulate a preview
-- when running automated tests.
return parms.test == 'preview'
end
local success, revid = pcall(function ()
return (parms.frame):preprocess('{{REVISIONID}}') end)
return success and (revid == '')
end
local want_warning = is_warning and
not config.warnings and -- show unobtrusive warnings if config.warnings not configured
not msg.nowarn -- but use msg settings, not standard warning, if specified
local title = string.gsub(msg[1] or 'Missing message', '$%d+', parts)
local text = want_warning and '*' or msg[2] or 'Missing message'
local cat = wanted_category(msg[3], mcode[2], want_warning)
local anchor = msg[4] or ''
local fmtkey = ispreview() and 'cvt_format_preview' or
(want_warning and 'cvt_format2' or msg.format or 'cvt_format')
local fmt = text_code.all_messages[fmtkey] or 'convert: bug'
return subparm(fmt, title:gsub('"', '&quot;'), text, cat, anchor)
end
return 'Convert internal error: unknown message'
end

function add_warning(parms, level, key, text1, text2) -- for forward declaration above
-- If enabled, add a warning that will be displayed after the convert result.
-- A higher level is more verbose: more kinds of warnings are displayed.
-- To reduce output noise, only the first warning is displayed.
if level <= (tonumber(config.warnings) or 1) then
if parms.warnings == nil then
parms.warnings = message(parms, { key, text1, text2 }, true)
end
end
end

local function spell_number(parms, inout, number, numerator, denominator)
-- Return result of spelling (number, numerator, denominator), or
-- return nil if spelling is not available or not supported for given text.
-- Examples (each value must be a string or nil):
-- number numerator denominator output
-- ------ --------- ----------- -------------------
-- "1.23" nil nil one point two three
-- "1" "2" "3" one and two thirds
-- nil "2" "3" two thirds
if not speller then
local function get_speller(module)
return require(module).spell_number
end
local success
success, speller = pcall(get_speller, spell_module)
if not success or type(speller) ~= 'function' then
add_warning(parms, 1, 'cvt_no_spell', 'spell')
return nil
end
end
local case
if parms.spell_upper == inout then
case = true
parms.spell_upper = nil -- only uppercase first word in a multiple unit
end
local sp = not parms.opt_sp_us
local adj = parms.opt_adjectival
return speller(number, numerator, denominator, case, sp, adj)
end

------------------------------------------------------------------------
-- BEGIN: Code required only for built-in units.
-- LATER: If need much more code, move to another module to simplify this module.
local function speed_of_sound(altitude)
-- This is for the Mach built-in unit of speed.
-- Return speed of sound in metres per second at given altitude in feet.
-- If no altitude given, use default (zero altitude = sea level).
-- Table gives speed of sound in miles per hour at various altitudes:
-- altitude = -17,499 to 302,499 feet
-- mach_table[a + 4] = s where
-- a = (altitude / 5000) rounded to nearest integer (-3 to 60)
-- s = speed of sound (mph) at that altitude
-- LATER: Should calculate result from an interpolation between the next
-- lower and higher altitudes in table, rather than rounding to nearest.
-- From: http://www.aerospaceweb.org/question/atmosphere/q0112.shtml
local mach_table = { -- a =
799.5, 787.0, 774.2, 761.207051, -- -3 to 0
748.0, 734.6, 721.0, 707.0, 692.8, 678.3, 663.5, 660.1, 660.1, 660.1, -- 1 to 10
660.1, 660.1, 660.1, 662.0, 664.3, 666.5, 668.9, 671.1, 673.4, 675.6, -- 11 to 20
677.9, 683.7, 689.9, 696.0, 702.1, 708.1, 714.0, 719.9, 725.8, 731.6, -- 21 to 30
737.3, 737.7, 737.7, 736.2, 730.5, 724.6, 718.8, 712.9, 707.0, 701.1, -- 31 to 40
695.0, 688.9, 682.8, 676.6, 670.4, 664.1, 657.8, 652.9, 648.3, 643.7, -- 41 to 50
639.1, 634.4, 629.6, 624.8, 620.0, 615.2, 613.2, 613.2, 613.2, 613.5, -- 51 to 60
}
altitude = altitude or 0
local a = (altitude < 0) and -altitude or altitude
a = floor(a / 5000 + 0.5)
if altitude < 0 then
a = -a
end
if a < -3 then
a = -3
elseif a > 60 then
a = 60
end
return mach_table[a + 4] * 0.44704 -- mph converted to m/s
end
-- END: Code required only for built-in units.
------------------------------------------------------------------------

local function get_range(word)
-- Return a range (string or table) corresponding to word (like "to"),
-- or return nil if not a range word.
local ranges = text_code.ranges
return ranges.types[word] or ranges.types[ranges.aliases[word]]
end

local function check_mismatch(unit1, unit2)
-- If unit1 cannot be converted to unit2, return an error message table.
-- This allows conversion between units of the same type, and between
-- Nm (normally torque) and ftlb (energy), as in gun-related articles.
-- This works because Nm is the base unit (scale = 1) for both the
-- primary type (torque), and the alternate type (energy, where Nm = J).
-- A match occurs if the primary types are the same, or if unit1 matches
-- the alternate type of unit2, and vice versa. That provides a whitelist
-- of which conversions are permitted between normally incompatible types.
if unit1.utype == unit2.utype or
(unit1.utype == unit2.alttype and unit1.alttype == unit2.utype) then
return nil
end
return { 'cvt_mismatch', unit1.utype, unit2.utype }
end

local function override_from(out_table, in_table, fields)
-- Copy the specified fields from in_table to out_table, but do not
-- copy nil fields (keep any corresponding field in out_table).
for _, field in ipairs(fields) do
if in_table[field] then
out_table[field] = in_table[field]
end
end
end

local function shallow_copy(t)
-- Return a shallow copy of table t.
-- Do not need the features and overhead of the Scribunto mw.clone().
local result = {}
for k, v in pairs(t) do
result[k] = v
end
return result
end

local unit_mt = {
-- Metatable to get missing values for a unit that does not accept SI prefixes.
-- Warning: The boolean value 'false' is returned for any missing field
-- so __index is not called twice for the same field in a given unit.
__index = function (self, key)
local value
if key == 'name1' or key == 'sym_us' then
value = self.symbol
elseif key == 'name2' then
value = self.name1 .. plural_suffix
elseif key == 'name1_us' then
value = self.name1
if not rawget(self, 'name2_us') then
-- If name1_us is 'foot', do not make name2_us by appending plural_suffix.
self.name2_us = self.name2
end
elseif key == 'name2_us' then
local raw1_us = rawget(self, 'name1_us')
if raw1_us then
value = raw1_us .. plural_suffix
else
value = self.name2
end
elseif key == 'link' then
value = self.name1
else
value = false
end
rawset(self, key, value)
return value
end
}

local function prefixed_name(unit, name, index)
-- Return unit name with SI prefix inserted at correct position.
-- index = 1 (name1), 2 (name2), 3 (name1_us), 4 (name2_us).
-- The position is a byte (not character) index, so use Lua's sub().
local pos = rawget(unit, 'prefix_position')
if type(pos) == 'string' then
pos = tonumber(split(pos, ',')[index])
end
if pos then
return name:sub(1, pos - 1) .. unit.si_name .. name:sub(pos)
end
return unit.si_name .. name
end

local unit_prefixed_mt = {
-- Metatable to get missing values for a unit that accepts SI prefixes.
-- Before use, fields si_name, si_prefix must be defined.
-- The unit must define _symbol, _name1 and
-- may define _sym_us, _name1_us, _name2_us
-- (_sym_us, _name2_us may be defined for a language using sp=us
-- to refer to a variant unrelated to U.S. units).
__index = function (self, key)
local value
if key == 'symbol' then
value = self.si_prefix .. self._symbol
elseif key == 'sym_us' then
value = rawget(self, '_sym_us')
if value then
value = self.si_prefix .. value
else
value = self.symbol
end
elseif key == 'name1' then
value = prefixed_name(self, self._name1, 1)
elseif key == 'name2' then
value = rawget(self, '_name2')
if value then
value = prefixed_name(self, value, 2)
else
value = self.name1 .. plural_suffix
end
elseif key == 'name1_us' then
value = rawget(self, '_name1_us')
if value then
value = prefixed_name(self, value, 3)
else
value = self.name1
end
elseif key == 'name2_us' then
value = rawget(self, '_name2_us')
if value then
value = prefixed_name(self, value, 4)
elseif rawget(self, '_name1_us') then
value = self.name1_us .. plural_suffix
else
value = self.name2
end
elseif key == 'link' then
value = self.name1
else
value = false
end
rawset(self, key, value)
return value
end
}

local unit_per_mt = {
-- Metatable to get values for a per unit of form "x/y".
-- This is never called to determine a unit name or link because per units
-- are handled as a special case.
-- Similarly, the default output is handled elsewhere, and for a symbol
-- this is only called from get_default() for default_exceptions.
__index = function (self, key)
local value
if key == 'symbol' then
local per = self.per
local unit1, unit2 = per[1], per[2]
if unit1 then
value = unit1[key] .. '/' .. unit2[key]
else
value = '/' .. unit2[key]
end
elseif key == 'sym_us' then
value = self.symbol
elseif key == 'scale' then
local per = self.per
local unit1, unit2 = per[1], per[2]
value = (unit1 and unit1.scale or 1) * self.scalemultiplier / unit2.scale
else
value = false
end
rawset(self, key, value)
return value
end
}

local function make_per(unitcode, unit_table, ulookup)
-- Return true, t where t is a per unit with unit codes expanded to unit tables,
-- or return false, t where t is an error message table.
local result = {
unitcode = unitcode,
utype = unit_table.utype,
per = {}
}
override_from(result, unit_table, { 'invert', 'iscomplex', 'default', 'link', 'symbol', 'symlink' })
result.symbol_raw = (result.symbol or false) -- to distinguish between a defined exception and a metatable calculation
local prefix
for i, v in ipairs(unit_table.per) do
if i == 1 and v == '' then
-- First unit symbol can be empty; that gives a nil first unit table.
elseif i == 1 and text_code.currency[v] then
prefix = currency_text or v
else
local success, t = ulookup(v)
if not success then return false, t end
result.per[i] = t
end
end
local multiplier = unit_table.multiplier
if not result.utype then
-- Creating an automatic per unit.
local unit1 = result.per[1]
local utype = (unit1 and unit1.utype or prefix or '') .. '/' .. result.per[2].utype
local t = data_code.per_unit_fixups[utype]
if t then
if type(t) == 'table' then
utype = t.utype or utype
result.link = result.link or t.link
multiplier = multiplier or t.multiplier
else
utype = t
end
end
result.utype = utype
end
result.scalemultiplier = multiplier or 1
result.vprefix = prefix or false -- set to non-nil to avoid calling __index
return true, setmetatable(result, unit_per_mt)
end

local function lookup(parms, unitcode, what, utable, fails, depth)
-- Return true, t where t is a copy of the unit's converter table,
-- or return false, t where t is an error message table.
-- Parameter 'what' determines whether combination units are accepted:
-- 'no_combination' : single unit only
-- 'any_combination' : single unit or combination or output multiple
-- 'only_multiple' : single unit or output multiple only
-- Parameter unitcode is a symbol (like 'g'), with an optional SI prefix (like 'kg').
-- If, for example, 'kg' is in this table, that entry is used;
-- otherwise the prefix ('k') is applied to the base unit ('g').
-- If unitcode is a known combination code (and if allowed by what),
-- a table of output multiple unit tables is included in the result.
-- For compatibility with the old template, an underscore in a unitcode is
-- replaced with a space so usage like {{convert|350|board_feet}} works.
-- Wikignomes may also put two spaces or "&nbsp;" in combinations, so
-- replace underscore, "&nbsp;", and multiple spaces with a single space.
utable = utable or parms.unittable or all_units
fails = fails or {}
depth = depth and depth + 1 or 1
if depth > 9 then
-- There are ways to mistakenly define units which result in infinite
-- recursion when lookup() is called. That gives a long delay and very
-- confusing error messages, so the depth parameter is used as a guard.
return false, { 'cvt_lookup', unitcode }
end
if unitcode == nil or unitcode == '' then
return false, { 'cvt_no_unit' }
end
unitcode = unitcode:gsub('_', ' '):gsub('&nbsp;', ' '):gsub(' +', ' ')
local function call_make_per(t)
return make_per(unitcode, t,
function (ucode) return lookup(parms, ucode, 'no_combination', utable, fails, depth) end
)
end
local t = utable[unitcode]
if t then
if t.shouldbe then
return false, { 'cvt_should_be', t.shouldbe }
end
if t.sp_us then
parms.opt_sp_us = true
end
local target = t.target -- nil, or unitcode is an alias for this target
if target then
local success, result = lookup(parms, target, what, utable, fails, depth)
if not success then return false, result end
override_from(result, t, { 'customary', 'default', 'link', 'symbol', 'symlink' })
local multiplier = t.multiplier
if multiplier then
result.multiplier = tostring(multiplier)
result.scale = result.scale * multiplier
end
return true, result
end
if t.per then
return call_make_per(t)
end
local combo = t.combination -- nil or a table of unitcodes
if combo then
local multiple = t.multiple
if what == 'no_combination' or (what == 'only_multiple' and not multiple) then
return false, { 'cvt_bad_unit', unitcode }
end
-- Recursively create a combination table containing the
-- converter table of each unitcode.
local result = { utype = t.utype, multiple = multiple, combination = {} }
local cvt = result.combination
for i, v in ipairs(combo) do
local success, t = lookup(parms, v, multiple and 'no_combination' or 'only_multiple', utable, fails, depth)
if not success then return false, t end
cvt[i] = t
end
return true, result
end
local result = shallow_copy(t)
result.unitcode = unitcode
if result.prefixes then
result.si_name = ''
result.si_prefix = ''
return true, setmetatable(result, unit_prefixed_mt)
end
return true, setmetatable(result, unit_mt)
end
local SIprefixes = text_code.SIprefixes
for plen = SIprefixes[1] or 2, 1, -1 do
-- Look for an SI prefix; should never occur with an alias.
-- Check for longer prefix first ('dam' is decametre).
-- SIprefixes[1] = prefix maximum #characters (as seen by mw.ustring.sub).
local prefix = usub(unitcode, 1, plen)
local si = SIprefixes[prefix]
if si then
local t = utable[usub(unitcode, plen+1)]
if t and t.prefixes then
local result = shallow_copy(t)
result.unitcode = unitcode
result.si_name = parms.opt_sp_us and si.name_us or si.name
result.si_prefix = si.prefix or prefix
result.scale = t.scale * 10 ^ (si.exponent * t.prefixes)
return true, setmetatable(result, unit_prefixed_mt)
end
end
end
-- Accept any unit with an engineering notation prefix like "e6cuft"
-- (million cubic feet), but not chained prefixes like "e3e6cuft",
-- and not if the unit is a combination or multiple,
-- and not if the unit has an offset or is a built-in.
-- Only en digits are accepted.
local has_plus = unitcode:find('+', 1, true)
if not has_plus then
local exponent, baseunit = unitcode:match('^e(%d+)(.*)')
if exponent then
local engscale = text_code.eng_scales[exponent]
if engscale then
local success, result = lookup(parms, baseunit, 'no_combination', utable, fails, depth)
if success and not (result.offset or result.builtin or result.engscale) then
result.unitcode = unitcode -- 'e6cuft' not 'cuft'
result.defkey = unitcode -- key to lookup default exception
result.engscale = engscale
result.scale = result.scale * 10 ^ tonumber(exponent)
return true, result
end
end
end
end
-- Accept user-defined combinations like "acre+m2+ha" or "acre m2 ha" for output.
-- If '+' is used, each unit code can include a space, and any error is fatal.
-- If ' ' is used and if each space-separated word is a unit code, it is a combo,
-- but errors are not fatal so the unit code can be looked up as an extra unit.
local err_is_fatal
local combo = collection()
if has_plus then
err_is_fatal = true
for item in (unitcode .. '+'):gmatch('%s*(.-)%s*%+') do
if item ~= '' then
combo:add(item)
end
end
elseif unitcode:find('%s') then
for item in unitcode:gmatch('%S+') do
combo:add(item)
end
end
if combo.n > 1 then
local function lookup_combo()
if what == 'no_combination' or what == 'only_multiple' then
return false, { 'cvt_bad_unit', unitcode }
end
local result = { combination = {} }
local cvt = result.combination
for i, v in ipairs(combo) do
local success, t = lookup(parms, v, 'only_multiple', utable, fails, depth)
if not success then return false, t end
if i == 1 then
result.utype = t.utype
else
local mismatch = check_mismatch(result, t)
if mismatch then
return false, mismatch
end
end
cvt[i] = t
end
return true, result
end
local success, result = lookup_combo()
if success or err_is_fatal then
return success, result
end
end
-- Look for x/y; split on right-most slash to get scale correct (x/y/z is x/y per z).
local top, bottom = unitcode:match('^(.-)/([^/]+)$')
if top and not unitcode:find('e%d') then
-- If valid, create an automatic per unit for an "x/y" unit code.
-- The unitcode must not include extraneous spaces.
-- Engineering notation (apart from at start and which has been stripped before here),
-- is not supported so do not make a per unit if find text like 'e3' in unitcode.
local success, result = call_make_per({ per = {top, bottom} })
if success then
return true, result
end
end
if not parms.opt_ignore_error and not get_range(unitcode) then
-- Want the "what links here" list for the extra_module to show only cases
-- where an extra unit is used, so do not require it if invoked from {{val}}
-- or if looking up a range word which cannot be a unit.
if not extra_units then
local success, extra = pcall(function () return require(extra_module).extra_units end)
if success and type(extra) == 'table' then
extra_units = extra
end
end
if extra_units then
-- A unit in one data table might refer to a unit in the other table, so
-- switch between them, relying on fails or depth to terminate loops.
if not fails[unitcode] then
fails[unitcode] = true
local other = (utable == all_units) and extra_units or all_units
local success, result = lookup(parms, unitcode, what, other, fails, depth)
if success then
return true, result
end
end
end
end
if to_en_table then
-- At fawiki it is common to translate all digits so a unit like "km2" becomes "km۲".
local en_code = ustring.gsub(unitcode, '%d', to_en_table)
if en_code ~= unitcode then
return lookup(parms, en_code, what, utable, fails, depth)
end
end
return false, { 'cvt_unknown', unitcode }
end

local function valid_number(num)
-- Return true if num is a valid number.
-- In Scribunto (different from some standard Lua), when expressed as a string,
-- overflow or other problems are indicated with text like "inf" or "nan"
-- which are regarded as invalid here (each contains "n").
if type(num) == 'number' and tostring(num):find('n', 1, true) == nil then
return true
end
end

local function hyphenated(name, parts)
-- Return a hyphenated form of given name (for adjectival usage).
-- The name may be linked and the target of the link must not be changed.
-- Hypothetical examples:
-- [[long ton|ton]] → [[long ton|ton]] (no change)
-- [[tonne|long ton]] → [[tonne|long-ton]]
-- [[metric ton|long ton]] → [[metric ton|long-ton]]
-- [[long ton]] → [[long ton|long-ton]]
-- Input can also have multiple links in a single name like:
-- [[United States customary units|U.S.]] [[US gallon|gallon]]
-- [[mile]]s per [[United States customary units|U.S.]] [[quart]]
-- [[long ton]]s per [[short ton]]
-- Assume that links cannot be nested (never like "[[abc[[def]]ghi]]").
-- This uses a simple and efficient procedure that works for most cases.
-- Some units (if used) would require more, and can later think about
-- adding a method to handle exceptions.
-- The procedure is to replace each space with a hyphen, but
-- not a space after ')' [for "(pre-1954&nbsp;US) nautical mile"], and
-- not spaces immediately before '(' or in '(...)' [for cases like
-- "British thermal unit (ISO)" and "Calorie (International Steam Table)"].
if name:find(' ', 1, true) then
if parts then
local pos
if name:sub(1, 1) == '(' then
pos = name:find(')', 1, true)
if pos then
return name:sub(1, pos+1) .. name:sub(pos+2):gsub(' ', '-')
end
elseif name:sub(-1) == ')' then
pos = name:find('(', 1, true)
if pos then
return name:sub(1, pos-2):gsub(' ', '-') .. name:sub(pos-1)
end
end
return name:gsub(' ', '-')
end
parts = collection()
for before, item, after in name:gmatch('([^[]*)(%[%[[^[]*%]%])([^[]*)') do
if item:find(' ', 1, true) then
local prefix
local plen = item:find('|', 1, true)
if plen then
prefix = item:sub(1, plen)
item = item:sub(plen + 1, -3)
else
prefix = item:sub(1, -3) .. '|'
item = item:sub(3, -3)
end
item = prefix .. hyphenated(item, parts) .. ']]'
end
parts:add(before:gsub(' ', '-') .. item .. after:gsub(' ', '-'))
end
if parts.n == 0 then
-- No link like "[[...]]" was found in the original name.
parts:add(hyphenated(name, parts))
end
return table.concat(parts)
end
return name
end

local function hyphenated_maybe(parms, want_name, sep, id, inout)
-- Return s, f where
-- s = id, possibly modified
-- f = true if hyphenated
-- Possible modifications: hyphenate; prepend '-'; append mid text.
if id == nil or id == '' then
return ''
end
local mid = (inout == (parms.opt_flip and 'out' or 'in')) and parms.mid or ''
if want_name then
if parms.opt_adjectival then
return '-' .. hyphenated(id) .. mid, true
end
if parms.opt_add_s and id:sub(-1) ~= 's' then
id = id .. 's' -- for nowiki
end
end
return sep .. id .. mid
end

local function use_minus(text)
-- Return text with Unicode minus instead of '-', if present.
if text:sub(1, 1) == '-' then
return MINUS .. text:sub(2)
end
return text
end

local function digit_groups(parms, text, method)
-- Return a numbered table of groups of digits (left-to-right, in local language).
-- Parameter method is a number or nil:
-- 3 for 3-digit grouping (default), or
-- 2 for 3-then-2 grouping (only for digits before decimal mark).
local len_right
local len_left = text:find('.', 1, true)
if len_left then
len_right = #text - len_left
len_left = len_left - 1
else
len_left = #text
end
local twos = method == 2 and len_left > 5
local groups = collection()
local run = len_left
local n
if run < 4 or (run == 4 and parms.opt_comma5) then
if parms.opt_gaps then
n = run
else
n = #text
end
elseif twos then
n = run % 2 == 0 and 1 or 2
else
n = run % 3 == 0 and 3 or run % 3
end
while run > 0 do
groups:add(n)
run = run - n
n = (twos and run > 3) and 2 or 3
end
if len_right then
if groups.n == 0 then
groups:add(0)
end
if parms.opt_gaps and len_right > 3 then
local want4 = not parms.opt_gaps3 -- true gives no gap before trailing single digit
local isfirst = true
run = len_right
while run > 0 do
n = (want4 and run == 4) and 4 or (run > 3 and 3 or run)
if isfirst then
isfirst = false
groups[groups.n] = groups[groups.n] + 1 + n
else
groups:add(n)
end
run = run - n
end
else
groups[groups.n] = groups[groups.n] + 1 + len_right
end
end
local pos = 1
for i, length in ipairs(groups) do
groups[i] = from_en(text:sub(pos, pos + length - 1))
pos = pos + length
end
return groups
end

function with_separator(parms, text) -- for forward declaration above
-- Input text is a number in en digits with optional '.' decimal mark.
-- Return an equivalent, formatted for display:
-- with a custom decimal mark instead of '.', if wanted
-- with thousand separators inserted, if wanted
-- digits in local language
-- The given text is like '123' or '123.' or '12345.6789'.
-- The text has no sign (caller inserts that later, if necessary).
-- When using gaps, they are inserted before and after the decimal mark.
-- Separators are inserted only before the decimal mark.
-- A trailing dot (as in '123.') is removed because their use appears to
-- be accidental, and such a number should be shown as '123' or '123.0'.
-- It is useful for convert to suppress the dot so, for example, '4000.'
-- is a simple way of indicating that all the digits are significant.
if text:sub(-1) == '.' then
text = text:sub(1, -2)
end
if #text < 4 or parms.opt_nocomma or numsep == '' then
return from_en(text)
end
local groups = digit_groups(parms, text, group_method)
if parms.opt_gaps then
if groups.n <= 1 then
return groups[1] or ''
end
local nowrap = '<span style="white-space: nowrap">'
local gap = '<span style="margin-left: 0.25em">'
local close = '</span>'
return nowrap .. groups[1] .. gap .. table.concat(groups, close .. gap, 2, groups.n) .. close .. close
end
return table.concat(groups, numsep)
end

-- An input value like 1.23e12 is displayed using scientific notation (1.23×10¹²).
-- That also makes the output use scientific notation, except for small values.
-- In addition, very small or very large output values use scientific notation.
-- Use format(fmtpower, significand, '10', exponent) where each argument is a string.
local fmtpower = '%s<span style="margin:0 .15em 0 .25em">×</span>%s<sup>%s</sup>'

local function with_exponent(parms, show, exponent)
-- Return wikitext to display the implied value in scientific notation.
-- Input uses en digits; output uses digits in local language.
return format(fmtpower, with_separator(parms, show), from_en('10'), use_minus(from_en(tostring(exponent))))
end

local function make_sigfig(value, sigfig)
-- Return show, exponent that are equivalent to the result of
-- converting the number 'value' (where value >= 0) to a string,
-- rounded to 'sigfig' significant figures.
-- The returned items are:
-- show: a string of digits; no sign and no dot;
-- there is an implied dot before show.
-- exponent: a number (an integer) to shift the implied dot.
-- Resulting value = tonumber('.' .. show) * 10^exponent.
-- Examples:
-- make_sigfig(23.456, 3) returns '235', 2 (.235 * 10^2).
-- make_sigfig(0.0023456, 3) returns '235', -2 (.235 * 10^-2).
-- make_sigfig(0, 3) returns '000', 1 (.000 * 10^1).
if sigfig <= 0 then
sigfig = 1
elseif sigfig > maxsigfig then
sigfig = maxsigfig
end
if value == 0 then
return string.rep('0', sigfig), 1
end
local exp, fracpart = math.modf(log10(value))
if fracpart >= 0 then
fracpart = fracpart - 1
exp = exp + 1
end
local digits = format('%.0f', 10^(fracpart + sigfig))
if #digits > sigfig then
-- Overflow (for sigfig=3: like 0.9999 rounding to "1000"; need "100").
digits = digits:sub(1, sigfig)
exp = exp + 1
end
assert(#digits == sigfig, 'Bug: rounded number has wrong length')
return digits, exp
end

-- Fraction output format.
local fracfmt = {
{ -- Like {{frac}} (fraction slash).
-- 1/2 : sign, numerator, denominator
-- 1+2/3 : signed_wholenumber, numerator, denominator
'<span class="frac nowrap">%s<sup>%s</sup>&frasl;<sub>%s</sub></span>',
'<span class="frac nowrap">%s<span class="visualhide">&nbsp;</span><sup>%s</sup>&frasl;<sub>%s</sub></span>',
},
{ -- Like {{sfrac}} (fraction horizontal bar).
-- 1//2 : sign, numerator, denominator (sign should probably be before the fraction, but then it can wrap, and html is already too long)
-- 1+2//3 : signed_wholenumber, numerator, denominator
'<span class="sfrac nowrap" style="display:inline-block; vertical-align:-0.5em; font-size:85%%; text-align:center;"><span style="display:block; line-height:1em; padding:0 0.1em;">%s%s</span><span class="visualhide">/</span><span style="display:block; line-height:1em; padding:0 0.1em; border-top:1px solid;">%s</span></span>',
'<span class="sfrac nowrap">%s<span class="visualhide">&nbsp;</span><span style="display:inline-block; vertical-align:-0.5em; font-size:85%%; text-align:center;"><span style="display:block; line-height:1em; padding:0 0.1em;">%s</span><span class="visualhide">/</span><span style="display:block; line-height:1em; padding:0 0.1em; border-top:1px solid;">%s</span></span></span>',
},
}

local function format_fraction(parms, inout, negative, wholestr, numstr, denstr, do_spell, style)
-- Return wikitext for a fraction, possibly spelled.
-- Inputs use en digits and have no sign; output uses digits in local language.
local wikitext
if not style then
style = parms.opt_fraction_horizontal and 2 or 1
end
if wholestr == '' then
wholestr = nil
end
if wholestr then
local decorated = with_separator(parms, wholestr)
if negative then
decorated = MINUS .. decorated
end
local fmt = fracfmt[style][2]
wikitext = format(fmt, decorated, from_en(numstr), from_en(denstr))
else
local sign = negative and MINUS or ''
wikitext = format(fracfmt[style][1], sign, from_en(numstr), from_en(denstr))
end
if do_spell then
if negative then
if wholestr then
wholestr = '-' .. wholestr
else
numstr = '-' .. numstr
end
end
wikitext = spell_number(parms, inout, wholestr, numstr, denstr) or wikitext
end
return wikitext
end

local function format_number(parms, show, exponent, isnegative)
-- Parameter show is a string or a table containing strings.
-- Each string is a formatted number in en digits and optional '.' decimal mark.
-- A table represents a fraction: integer, numerator, denominator;
-- if a table is given, exponent must be nil.
-- Return t where t is a table with fields:
-- show = wikitext formatted to display implied value
-- (digits in local language)
-- is_scientific = true if show uses scientific notation
-- clean = unformatted show (possibly adjusted and with inserted '.')
-- (en digits)
-- sign = '' or MINUS
-- exponent = exponent (possibly adjusted)
-- The clean and exponent fields can be used to calculate the
-- rounded absolute value, if needed.
--
-- The value implied by the arguments is found from:
-- exponent is nil; and
-- show is a string of digits (no sign), with an optional dot;
-- show = '123.4' is value 123.4, '1234' is value 1234.0;
-- or:
-- exponent is an integer indicating where dot should be;
-- show is a string of digits (no sign and no dot);
-- there is an implied dot before show;
-- show does not start with '0';
-- show = '1234', exponent = 3 is value 0.1234*10^3 = 123.4.
--
-- The formatted result:
-- * Is for an output value and is spelled if wanted and possible.
-- * Includes a Unicode minus if isnegative and not spelled.
-- * Uses a custom decimal mark, if wanted.
-- * Has digits grouped where necessary, if wanted.
-- * Uses scientific notation if requested, or for very small or large values
-- (which forces result to not be spelled).
-- * Has no more than maxsigfig significant digits
-- (same as old template and {{#expr}}).
local xhi, xlo -- these control when scientific notation (exponent) is used
if parms.opt_scientific then
xhi, xlo = 4, 2 -- default for output if input uses e-notation
elseif parms.opt_scientific_always then
xhi, xlo = 0, 0 -- always use scientific notation (experimental)
else
xhi, xlo = 10, 4 -- default
end
local sign = isnegative and MINUS or ''
local maxlen = maxsigfig
local tfrac
if type(show) == 'table' then
tfrac = show
show = tfrac.wholestr
assert(exponent == nil, 'Bug: exponent given with fraction')
end
if not tfrac and not exponent then
local integer, dot, decimals = show:match('^(%d*)(%.?)(.*)')
if integer == '0' or integer == '' then
local zeros, figs = decimals:match('^(0*)([^0]?.*)')
if #figs == 0 then
if #zeros > maxlen then
show = '0.' .. zeros:sub(1, maxlen)
end
elseif #zeros >= xlo then
show = figs
exponent = -#zeros
elseif #figs > maxlen then
show = '0.' .. zeros .. figs:sub(1, maxlen)
end
elseif #integer >= xhi then
show = integer .. decimals
exponent = #integer
else
maxlen = maxlen + #dot
if #show > maxlen then
show = show:sub(1, maxlen)
end
end
end
if exponent then
local function zeros(n)
return string.rep('0', n)
end
if #show > maxlen then
show = show:sub(1, maxlen)
end
if exponent > xhi or exponent <= -xlo or (exponent == xhi and show ~= '1' .. zeros(xhi - 1)) then
-- When xhi, xlo = 10, 4 (the default), scientific notation is used if the
-- rounded value satisfies: value >= 1e9 or value < 1e-4 (1e9 = 0.1e10),
-- except if show is '1000000000' (1e9), for example:
-- {{convert|1000000000|m|m|sigfig=10}} → 1,000,000,000 metres (1,000,000,000 m)
local significand
if #show > 1 then
significand = show:sub(1, 1) .. '.' .. show:sub(2)
else
significand = show
end
return {
clean = '.' .. show,
exponent = exponent,
sign = sign,
show = sign .. with_exponent(parms, significand, exponent-1),
is_scientific = true,
}
end
if exponent >= #show then
show = show .. zeros(exponent - #show) -- result has no dot
elseif exponent <= 0 then
show = '0.' .. zeros(-exponent) .. show
else
show = show:sub(1, exponent) .. '.' .. show:sub(exponent+1)
end
end
local formatted_show
if tfrac then
show = tostring(tfrac.value) -- to set clean in returned table
formatted_show = format_fraction(parms, 'out', isnegative, tfrac.wholestr, tfrac.numstr, tfrac.denstr, parms.opt_spell_out)
else
if isnegative and show:match('^0.?0*$') then
sign = '' -- don't show minus if result is negative but rounds to zero
end
formatted_show = sign .. with_separator(parms, show)
if parms.opt_spell_out then
formatted_show = spell_number(parms, 'out', sign .. show) or formatted_show
end
end
return {
clean = show,
sign = sign,
show = formatted_show,
is_scientific = false, -- to avoid calling __index
}
end

local function extract_fraction(parms, text, negative)
-- If text represents a fraction, return
-- value, altvalue, show, denominator
-- where
-- value is a number (value of the fraction in argument text)
-- altvalue is an alternate interpretation of any fraction for the hands
-- unit where "12.1+3/4" means 12 hands 1.75 inches
-- show is a string (formatted text for display of an input value,
-- and is spelled if wanted and possible)
-- denominator is value of the denominator in the fraction
-- Otherwise, return nil.
-- Input uses en digits and '.' decimal mark (input has been translated).
-- Output uses digits in local language and local decimal mark, if any.
------------------------------------------------------------------------
-- Originally this function accepted x+y/z where x, y, z were any valid
-- numbers, possibly with a sign. For example '1.23e+2+1.2/2.4' = 123.5,
-- and '2-3/8' = 1.625. However, such usages were found to be errors or
-- misunderstandings, so since August 2014 the following restrictions apply:
-- x (if present) is an integer or has a single digit after decimal mark
-- y and z are unsigned integers
-- e-notation is not accepted
-- The overall number can start with '+' or '-' (so '12+3/4' and '+12+3/4'
-- and '-12-3/4' are valid).
-- Any leading negative sign is removed by the caller, so only inputs
-- like the following are accepted here (may have whitespace):
-- negative = false false true (there was a leading '-')
-- text = '2/3' '+2/3' '2/3'
-- text = '1+2/3' '+1+2/3' '1-2/3'
-- text = '12.3+1/2' '+12.3+1/2' '12.3-1/2'
-- Values like '12.3+1/2' are accepted, but are intended only for use
-- with the hands unit (not worth adding code to enforce that).
------------------------------------------------------------------------
local leading_plus, prefix, numstr, slashes, denstr =
text:match('^%s*(%+?)%s*(.-)%s*(%d+)%s*(/+)%s*(%d+)%s*$')
if not leading_plus then
-- Accept a single U+2044 fraction slash because that may be pasted.
leading_plus, prefix, numstr, denstr =
text:match('^%s*(%+?)%s*(.-)%s*(%d+)%s*⁄%s*(%d+)%s*$')
slashes = '/'
end
local numerator = tonumber(numstr)
local denominator = tonumber(denstr)
if numerator == nil or denominator == nil or (negative and leading_plus ~= '') then
return nil
end
local whole, wholestr
if prefix == '' then
wholestr = ''
whole = 0
else
-- Any prefix must be like '12+' or '12-' (whole number and fraction sign);
-- '12.3+' and '12.3-' are also accepted (single digit after decimal point)
-- because '12.3+1/2 hands' is valid (12 hands 3½ inches).
local num1, num2, frac_sign = prefix:match('^(%d+)(%.?%d?)%s*([+%-])$')
if num1 == nil then return nil end
if num2 == '' then -- num2 must be '' or like '.1' but not '.' or '.12'
wholestr = num1
else
if #num2 ~= 2 then return nil end
wholestr = num1 .. num2
end
if frac_sign ~= (negative and '-' or '+') then return nil end
whole = tonumber(wholestr)
if whole == nil then return nil end
end
local value = whole + numerator / denominator
if not valid_number(value) then return nil end
local altvalue = whole + numerator / (denominator * 10)
local style = #slashes -- kludge: 1 or 2 slashes can be used to select style
if style > 2 then style = 2 end
local wikitext = format_fraction(parms, 'in', negative, leading_plus .. wholestr, numstr, denstr, parms.opt_spell_in, style)
return value, altvalue, wikitext, denominator
end

local function extract_number(parms, text, another, no_fraction)
-- Return true, info if can extract a number from text,
-- where info is a table with the result,
-- or return false, t where t is an error message table.
-- Input can use en digits or digits in local language and can
-- have references at the end. Accepting references is intended
-- for use in infoboxes with a field for a value passed to convert.
-- Parameter another = true if the expected value is not the first.
-- Before processing, the input text is cleaned:
-- * Any thousand separators (valid or not) are removed.
-- * Any sign (and optional following whitespace) is replaced with
-- '-' (if negative) or '' (otherwise).
-- That replaces Unicode minus with '-'.
-- If successful, the returned info table contains named fields:
-- value = a valid number
-- altvalue = a valid number, usually same as value but different
-- if fraction used (for hands unit)
-- singular = true if value is 1 or -1 (to use singular form of units)
-- clean = cleaned text with any separators and sign removed
-- (en digits and '.' decimal mark)
-- show = text formatted for output, possibly with ref strip markers
-- (digits in local language and custom decimal mark)
-- The resulting show:
-- * Is for an input value and is spelled if wanted and possible.
-- * Has a rounded value, if wanted.
-- * Has digits grouped where necessary, if wanted.
-- * If negative, a Unicode minus is used; otherwise the sign is
-- '+' (if the input text used '+'), or is '' (if no sign in input).
text = strip(text or '')
local reference
local pos = text:find('\127', 1, true)
if pos then
local before = text:sub(1, pos - 1)
local remainder = text:sub(pos)
local refs = {}
while #remainder > 0 do
local ref, spaces
ref, spaces, remainder = remainder:match('^(\127[^\127]*UNIQ[^\127]*%-ref[^\127]*\127)(%s*)(.*)')
if ref then
table.insert(refs, ref)
else
refs = {}
break
end
end
if #refs > 0 then
text = strip(before)
reference = table.concat(refs)
end
end
local clean = to_en(text, parms)
if clean == '' then
return false, { another and 'cvt_no_num2' or 'cvt_no_num' }
end
local isnegative, propersign = false, '' -- most common case
local singular, show, denominator
local value = tonumber(clean)
local altvalue
if value then
local sign = clean:sub(1, 1)
if sign == '+' or sign == '-' then
propersign = (sign == '+') and '+' or MINUS
clean = clean:sub(2)
end
if value < 0 then
isnegative = true
value = -value
end
else
local valstr
for _, prefix in ipairs({ '-', MINUS, '&minus;' }) do
-- Including '-' means inputs like '- 2' (with space) are accepted as -2.
-- It also sets isnegative in case input is a fraction like '-2-3/4'.
local plen = #prefix
if clean:sub(1, plen) == prefix then
valstr = clean:sub(plen + 1)
break
end
end
if valstr then
isnegative = true
propersign = MINUS
clean = valstr
value = tonumber(clean)
end
if value == nil then
if not no_fraction then
value, altvalue, show, denominator = extract_fraction(parms, clean, isnegative)
end
if value == nil then
return false, { 'cvt_bad_num', text }
end
if value <= 1 then
singular = true -- for example, "½ mile" or "one half mile" (singular unit)
end
end
end
if not valid_number(value) then -- for example, "1e310" may overflow
return false, { 'cvt_invalid_num' }
end
if show == nil then
-- clean is a non-empty string with no spaces, and does not represent a fraction,
-- and value = tonumber(clean) is a number >= 0.
-- If the input uses e-notation, show will be displayed using a power of ten, but
-- we use the number as given so it might not be normalized scientific notation.
-- The input value is spelled if specified so any e-notation is ignored;
-- that allows input like 2e6 to be spelled as "two million" which works
-- because the spell module converts '2e6' to '2000000' before spelling.
local function rounded(value, default, exponent)
local precision = parms.opt_ri
if precision then
local fmt = '%.' .. format('%d', precision) .. 'f'
local result = fmt:format(tonumber(value) + 2e-14) -- fudge for some common cases of bad rounding
if not exponent then
singular = (tonumber(result) == 1)
end
return result
end
return default
end
singular = (value == 1)
local scientific
local significand, exponent = clean:match('^([%d.]+)[Ee]([+%-]?%d+)')
if significand then
show = with_exponent(parms, rounded(significand, significand, exponent), exponent)
scientific = true
else
show = with_separator(parms, rounded(value, clean))
end
show = propersign .. show
if parms.opt_spell_in then
show = spell_number(parms, 'in', propersign .. rounded(value, clean)) or show
scientific = false
end
if scientific then
parms.opt_scientific = true
end
end
if isnegative and (value ~= 0) then
value = -value
altvalue = -(altvalue or value)
end
return true, {
value = value,
altvalue = altvalue or value,
singular = singular,
clean = clean,
show = show .. (reference or ''),
denominator = denominator,
}
end

local function get_number(text)
-- Return v, f where:
-- v = nil (text is not a number)
-- or
-- v = value of text (text is a number)
-- f = true if value is an integer
-- Input can use en digits or digits in local language,
-- but no separators, no Unicode minus, and no fraction.
if text then
local number = tonumber(to_en(text))
if number then
local _, fracpart = math.modf(number)
return number, (fracpart == 0)
end
end
end

local function gcd(a, b)
-- Return the greatest common denominator for the given values,
-- which are known to be positive integers.
if a > b then
a, b = b, a
end
if a <= 0 then
return b
end
local r = b % a
if r <= 0 then
return a
end
if r == 1 then
return 1
end
return gcd(r, a)
end

local function fraction_table(value, denominator)
-- Return value as a string or a table:
-- * If result is a string, there is no fraction, and the result
-- is value formatted as a string of en digits.
-- * If result is a table, it represents a fraction with named fields:
-- wholestr, numstr, denstr (strings of en digits for integer, numerator, denominator).
-- The result is rounded to the nearest multiple of (1/denominator).
-- If the multiple is zero, no fraction is included.
-- No fraction is included if value is very large as the fraction would
-- be unhelpful, particularly if scientific notation is required.
-- Input value is a non-negative number.
-- Input denominator is a positive integer for the desired fraction.
if value <= 0 then
return '0'
end
if denominator <= 0 or value > 1e8 then
return format('%.2f', value)
end
local integer, decimals = math.modf(value)
local numerator = floor((decimals * denominator) +
0.5 + 2e-14) -- add fudge for some common cases of bad rounding
if numerator >= denominator then
integer = integer + 1
numerator = 0
end
local wholestr = tostring(integer)
if numerator > 0 then
local div = gcd(numerator, denominator)
if div > 1 then
numerator = numerator / div
denominator = denominator / div
end
return {
wholestr = (integer > 0) and wholestr or '',
numstr = tostring(numerator),
denstr = tostring(denominator),
value = value,
}
end
return wholestr
end

local function preunits(count, preunit1, preunit2)
-- If count is 1:
-- ignore preunit2
-- return p1
-- else:
-- preunit1 is used for preunit2 if the latter is empty
-- return p1, p2
-- where:
-- p1 is text to insert before the input unit
-- p2 is text to insert before the output unit
-- p1 or p2 may be nil to mean "no preunit"
-- Using '+ ' gives output like "5+ feet" (no preceding space).
local function withspace(text, i)
-- Insert space at beginning if i == 1, or at end if i == -1.
-- However, no space is inserted if there is a space or '&nbsp;'
-- or '-' at that position ('-' is for adjectival text).
local current = text:sub(i, i)
if current == ' ' or current == '-' then
return text
end
if i == 1 then
current = text:sub(1, 6)
else
current = text:sub(-6, -1)
end
if current == '&nbsp;' then
return text
end
if i == 1 then
return ' ' .. text
end
return text .. ' '
end
preunit1 = preunit1 or ''
local trim1 = strip(preunit1)
if count == 1 then
if trim1 == '' then
return nil
end
return withspace(withspace(preunit1, 1), -1)
end
preunit2 = preunit2 or ''
local trim2 = strip(preunit2)
if trim1 == '' and trim2 == '' then
return nil, nil
end
if trim1 ~= '+' then
preunit1 = withspace(preunit1, 1)
end
if trim2 == '&#32;' then -- trick to make preunit2 empty
preunit2 = nil
elseif trim2 == '' then
preunit2 = preunit1
elseif trim2 ~= '+' then
preunit2 = withspace(preunit2, 1)
end
return preunit1, preunit2
end

local function range_text(range, want_name, parms, before, after, inout)
-- Return before .. rtext .. after
-- where rtext is the text that separates two values in a range.
local rtext, adj_text, exception
if type(range) == 'table' then
-- Table must specify range text for ('off' and 'on') or ('input' and 'output'),
-- and may specify range text for 'adj=on',
-- and may specify exception = true.
rtext = range[want_name and 'off' or 'on'] or
range[((inout == 'in') == (parms.opt_flip == true)) and 'output' or 'input']
adj_text = range['adj']
exception = range['exception']
else
rtext = range
end
if parms.opt_adjectival then
if want_name or (exception and parms.abbr_org == 'on') then
rtext = adj_text or rtext:gsub(' ', '-'):gsub('&nbsp;', '-')
end
end
if rtext == '–' and after:sub(1, #MINUS) == MINUS then
rtext = '&nbsp;– '
end
return before .. rtext .. after
end

local function get_composite(parms, iparm, in_unit_table)
-- Look for a composite input unit. For example, {{convert|1|yd|2|ft|3|in}}
-- would result in a call to this function with
-- iparm = 3 (parms[iparm] = "2", just after the first unit)
-- in_unit_table = (unit table for "yd"; contains value 1 for number of yards)
-- Return true, iparm, unit where
-- iparm = index just after the composite units (7 in above example)
-- unit = composite unit table holding all input units,
-- or return true if no composite unit is present in parms,
-- or return false, t where t is an error message table.
local default, subinfo
local composite_units, count = { in_unit_table }, 1
local fixups = {}
local total = in_unit_table.valinfo[1].value
local subunit = in_unit_table
while subunit.subdivs do -- subdivs is nil or a table of allowed subdivisions
local subcode = strip(parms[iparm+1])
local subdiv = subunit.subdivs[subcode] or subunit.subdivs[(all_units[subcode] or {}).target]
if not subdiv then
break
end
local success
success, subunit = lookup(parms, subcode, 'no_combination')
if not success then return false, subunit end -- should never occur
success, subinfo = extract_number(parms, parms[iparm])
if not success then return false, subinfo end
iparm = iparm + 2
subunit.inout = 'in'
subunit.valinfo = { subinfo }
-- Recalculate total as a number of subdivisions.
-- subdiv[1] = number of subdivisions per previous unit (integer > 1).
total = total * subdiv[1] + subinfo.value
if not default then -- set by the first subdiv with a default defined
default = subdiv.default
end
count = count + 1
composite_units[count] = subunit
if subdiv.unit or subdiv.name then
fixups[count] = { unit = subdiv.unit, name = subdiv.name, valinfo = subunit.valinfo }
end
end
if count == 1 then
return true -- no error and no composite unit
end
for i, fixup in pairs(fixups) do
local unit = fixup.unit
local name = fixup.name
if not unit or (count > 2 and name) then
composite_units[i].fixed_name = name
else
local success, alternate = lookup(parms, unit, 'no_combination')
if not success then return false, alternate end -- should never occur
alternate.inout = 'in'
alternate.valinfo = fixup.valinfo
composite_units[i] = alternate
end
end
return true, iparm, {
utype = in_unit_table.utype,
scale = subunit.scale, -- scale of last (least significant) unit
valinfo = { { value = total, clean = subinfo.clean, denominator = subinfo.denominator } },
composite = composite_units,
default = default or in_unit_table.default
}
end

local function translate_parms(parms, kv_pairs)
-- Update fields in parms by translating each key:value in kv_pairs to terms
-- used by this module (may involve translating from local language to English).
-- Also, checks are performed which may display warnings, if enabled.
-- Return true if successful or return false, t where t is an error message table.
currency_text = nil -- local testing can hold module in memory; must clear globals
local accept_any_text = {
input = true,
qid = true,
qual = true,
stylein = true,
styleout = true,
tracking = true,
}
if kv_pairs.adj and kv_pairs.sing then
-- For enwiki (before translation), warn if attempt to use adj and sing
-- as the latter is a deprecated alias for the former.
if kv_pairs.adj ~= kv_pairs.sing and kv_pairs.sing ~= '' then
add_warning(parms, 1, 'cvt_unknown_option', 'sing=' .. kv_pairs.sing)
end
kv_pairs.sing = nil
end
for loc_name, loc_value in pairs(kv_pairs) do
local en_name = text_code.en_option_name[loc_name]
if en_name then
local en_value
if en_name == '$' or en_name == 'frac' or en_name == 'sigfig' then
if loc_value == '' then
add_warning(parms, 2, 'cvt_empty_option', loc_name)
elseif en_name == '$' then
-- Value should be a single character like "€" for the euro currency symbol, but anything is accepted.
currency_text = (loc_value == 'euro') and '€' or loc_value
else
local minimum
local number, is_integer = get_number(loc_value)
if en_name == 'frac' then
minimum = 2
if number and number < 0 then
parms.opt_fraction_horizontal = true
number = -number
end
else
minimum = 1
end
if number and is_integer and number >= minimum then
en_value = number
else
add_warning(parms, 1, (en_name == 'frac' and 'cvt_bad_frac' or 'cvt_bad_sigfig'), loc_name .. '=' .. loc_value)
end
end
elseif accept_any_text[en_name] then
en_value = loc_value ~= '' and loc_value or nil -- accept non-empty user text with no validation
if en_name == 'input' then
-- May have something like {{convert|input=}} (empty input) if source is an infobox
-- with optional fields. In that case, want to output nothing rather than an error.
parms.input_text = loc_value -- keep input because parms.input is nil if loc_value == ''
end
else
en_value = text_code.en_option_value[en_name][loc_value]
if en_value and en_value:sub(-1) == '?' then
en_value = en_value:sub(1, -2)
add_warning(parms, -1, 'cvt_deprecated', loc_name .. '=' .. loc_value)
end
if en_value == nil then
if loc_value == '' then
add_warning(parms, 2, 'cvt_empty_option', loc_name)
else
add_warning(parms, 1, 'cvt_unknown_option', loc_name .. '=' .. loc_value)
end
elseif en_value == '' then
en_value = nil -- an ignored option like adj=off
elseif type(en_value) == 'string' and en_value:sub(1, 4) == 'opt_' then
for _, v in ipairs(split(en_value, ',')) do
local lhs, rhs = v:match('^(.-)=(.+)$')
if rhs then
parms[lhs] = tonumber(rhs) or rhs
else
parms[v] = true
end
end
en_value = nil
end
end
parms[en_name] = en_value
else
add_warning(parms, 1, 'cvt_unknown_option', loc_name .. '=' .. loc_value)
end
end
local abbr_entered = parms.abbr
local cfg_abbr = config.abbr
if cfg_abbr then
-- Don't warn if invalid because every convert would show that warning.
if cfg_abbr == 'on always' then
parms.abbr = 'on'
elseif cfg_abbr == 'off always' then
parms.abbr = 'off'
elseif parms.abbr == nil then
if cfg_abbr == 'on default' then
parms.abbr = 'on'
elseif cfg_abbr == 'off default' then
parms.abbr = 'off'
end
end
end
if parms.abbr then
if parms.abbr == 'unit' then
parms.abbr = 'on'
parms.number_word = true
end
parms.abbr_org = parms.abbr -- original abbr, before any flip
elseif parms.opt_hand_hh then
parms.abbr_org = 'on'
parms.abbr = 'on'
else
parms.abbr = 'out' -- default is to abbreviate output only (use symbol, not name)
end
if parms.opt_order_out then
-- Disable options that do not work in a useful way with order=out.
parms.opt_flip = nil -- override adj=flip
parms.opt_spell_in = nil
parms.opt_spell_out = nil
parms.opt_spell_upper = nil
end
if parms.opt_spell_out and not abbr_entered then
parms.abbr = 'off' -- should show unit name when spelling the output value
end
if parms.opt_flip then
local function swap_in_out(option)
local value = parms[option]
if value == 'in' then
parms[option] = 'out'
elseif value == 'out' then
parms[option] = 'in'
end
end
swap_in_out('abbr')
swap_in_out('lk')
if parms.opt_spell_in and not parms.opt_spell_out then
-- For simplicity, and because it does not appear to be needed,
-- user cannot set an option to spell the output only.
parms.opt_spell_in = nil
parms.opt_spell_out = true
end
end
if parms.opt_spell_upper then
parms.spell_upper = parms.opt_flip and 'out' or 'in'
end
if parms.opt_table or parms.opt_tablecen then
if abbr_entered == nil and parms.lk == nil then
parms.opt_values = true
end
parms.table_align = parms.opt_table and 'right' or 'center'
end
if parms.table_align or parms.opt_sortable_on then
parms.need_table_or_sort = true
end
local disp_joins = text_code.disp_joins
local default_joins = disp_joins['b']
parms.join_between = default_joins[3] or '; '
local disp = parms.disp
if disp == nil then -- special case for the most common setting
parms.joins = default_joins
elseif disp == 'x' then
-- Later, parms.joins is set from the input parameters.
else
-- Old template does this.
local abbr = parms.abbr
if disp == 'slash' then
if abbr_entered == nil then
disp = 'slash-nbsp'
elseif abbr == 'in' or abbr == 'out' then
disp = 'slash-sp'
else
disp = 'slash-nosp'
end
elseif disp == 'sqbr' then
if abbr == 'on' then
disp = 'sqbr-nbsp'
else
disp = 'sqbr-sp'
end
end
parms.joins = disp_joins[disp] or default_joins
parms.join_between = parms.joins[3] or parms.join_between
parms.wantname = parms.joins.wantname
end
if (en_default and not parms.opt_lang_local and (parms[1] or ''):find('%d')) or parms.opt_lang_en then
from_en_table = nil
end
if en_default and from_en_table then
-- For hiwiki: localized symbol/name is defined with the US symbol/name field,
-- and is used if output uses localized numbers.
parms.opt_sp_us = true
end
return true
end

local function get_values(parms)
-- If successful, update parms and return true, v, i where
-- v = table of input values
-- i = index to next entry in parms after those processed here
-- or return false, t where t is an error message table.
local valinfo = collection() -- numbered table of input values
local range = collection() -- numbered table of range items (having, for example, 2 range items requires 3 input values)
local had_nocomma -- true if removed "nocomma" kludge from second parameter (like "tonocomma")
local parm2 = strip(parms[2])
if parm2 and parm2:sub(-7, -1) == 'nocomma' then
parms[2] = strip(parm2:sub(1, -8))
parms.opt_nocomma = true
had_nocomma = true
end
local function extractor(i)
-- If the parameter is not a value, try unpacking it as a range ("1-23" for "1 to 23").
-- However, "-1-2/3" is a negative fraction (-1⅔), so it must be extracted first.
-- Do not unpack a parameter if it is like "3-1/2" which is sometimes incorrectly
-- used instead of "3+1/2" (and which should not be interpreted as "3 to ½").
-- Unpacked items are inserted into the parms table.
-- The tail recursion allows combinations like "1x2 to 3x4".
local valstr = strip(parms[i]) -- trim so any '-' as a negative sign will be at start
local success, result = extract_number(parms, valstr, i > 1)
if not success and valstr and i < 20 then -- check i to limit abuse
local lhs, sep, rhs = valstr:match('^(%S+)%s+(%S+)%s+(%S.*)')
if lhs and not (sep == '-' and rhs:match('/')) then
if sep:find('%d') then
return success, result -- to reject {{convert|1 234 567|m}} with a decent message (en only)
end
parms[i] = rhs
table.insert(parms, i, sep)
table.insert(parms, i, lhs)
return extractor(i)
end
if not valstr:match('%-.*/') then
for _, sep in ipairs(text_code.ranges.words) do
local start, stop = valstr:find(sep, 2, true) -- start at 2 to skip any negative sign for range '-'
if start then
parms[i] = valstr:sub(stop + 1)
table.insert(parms, i, sep)
table.insert(parms, i, valstr:sub(1, start - 1))
return extractor(i)
end
end
end
end
return success, result
end
local i = 1
local is_change
while true do
local success, info = extractor(i) -- need to set parms.opt_nocomma before calling this
if not success then return false, info end
i = i + 1
if is_change then
info.is_change = true -- value is after "±" and so is a change (significant for range like {{convert|5|±|5|°C}})
is_change = nil
end
valinfo:add(info)
local range_item = get_range(strip(parms[i]))
if not range_item then
break
end
i = i + 1
range:add(range_item)
if type(range_item) == 'table' then
-- For range "x", if append unit to some values, append it to all.
parms.in_range_x = parms.in_range_x or range_item.in_range_x
parms.out_range_x = parms.out_range_x or range_item.out_range_x
parms.abbr_range_x = parms.abbr_range_x or range_item.abbr_range_x
is_change = range_item.is_range_change
end
end
if range.n > 0 then
if range.n > 30 then -- limit abuse, although 4 is a more likely upper limit
return false, { 'cvt_invalid_num' } -- misleading message but it will do
end
parms.range = range
elseif had_nocomma then
return false, { 'cvt_unknown', parm2 }
end
return true, valinfo, i
end

local function simple_get_values(parms)
-- If input is like "{{convert|valid_value|valid_unit|...}}",
-- return true, i, in_unit, in_unit_table
-- i = index in parms of what follows valid_unit, if anything.
-- The valid_value is not negative and does not use a fraction, and
-- no options requiring further processing of the input are used.
-- Otherwise, return nothing or return false, parm1 for caller to interpret.
-- Testing shows this function is successful for 96% of converts in articles,
-- and that on average it speeds up converts by 8%.
if parms.opt_ri or parms.opt_spell_in then return end
local clean = to_en(strip(parms[1] or ''), parms)
if #clean > 10 or not clean:match('^[0-9.]+$') then
return false, clean
end
local value = tonumber(clean)
if not value then return end
local info = {
value = value,
altvalue = value,
singular = (value == 1),
clean = clean,
show = with_separator(parms, clean),
}
local in_unit = strip(parms[2])
local success, in_unit_table = lookup(parms, in_unit, 'no_combination')
if not success then return end
in_unit_table.valinfo = { info }
return true, 3, in_unit, in_unit_table
end

local function wikidata_call(parms, operation, ...)
-- Return true, s where s is the result of a Wikidata operation,
-- or return false, t where t is an error message table.
local function worker(...)
wikidata_code = wikidata_code or require(wikidata_module)
wikidata_data = wikidata_data or mw.loadData(wikidata_data_module)
return wikidata_code[operation](wikidata_data, ...)
end
local success, status, result = pcall(worker, ...)
if success then
return status, result
end
if parms.opt_sortable_debug then
-- Use debug=yes to crash if an error while accessing Wikidata.
error('Error accessing Wikidata: ' .. status, 0)
end
return false, { 'cvt_wd_fail' }
end

local function get_parms(parms, args)
-- If successful, update parms and return true, unit where
-- parms is a table of all arguments passed to the template
-- converted to named arguments, and
-- unit is the input unit table;
-- or return false, t where t is an error message table.
-- For special processing (not a convert), can also return
-- true, wikitext where wikitext is the final result.
-- The returned input unit table may be for a fake unit using the specified
-- unit code as the symbol and name, and with bad_mcode = message code table.
-- MediaWiki removes leading and trailing whitespace from the values of
-- named arguments. However, the values of numbered arguments include any
-- whitespace entered in the template, and whitespace is used by some
-- parameters (example: the numbered parameters associated with "disp=x").
local kv_pairs = {} -- table of input key:value pairs where key is a name; needed because cannot iterate parms and add new fields to it
for k, v in pairs(args) do
if type(k) == 'number' or k == 'test' then -- parameter "test" is reserved for testing and is not translated
parms[k] = v
else
kv_pairs[k] = v
end
end
if parms.test == 'wikidata' then
local ulookup = function (ucode)
-- Use empty table for parms so it does not accumulate results when used repeatedly.
return lookup({}, ucode, 'no_combination')
end
return wikidata_call(parms, '_listunits', ulookup)
end
local success, msg = translate_parms(parms, kv_pairs)
if not success then return false, msg end
if parms.input then
success, msg = wikidata_call(parms, '_adjustparameters', parms, 1)
if not success then return false, msg end
end
local success, i, in_unit, in_unit_table = simple_get_values(parms)
if not success then
if type(i) == 'string' and i:match('^NNN+$') then
-- Some infoboxes have examples like {{convert|NNN|m}} (3 or more "N").
-- Output an empty string for these.
return false, { 'cvt_no_output' }
end
local valinfo
success, valinfo, i = get_values(parms)
if not success then return false, valinfo end
in_unit = strip(parms[i])
i = i + 1
success, in_unit_table = lookup(parms, in_unit, 'no_combination')
if not success then
in_unit = in_unit or ''
if parms.opt_ignore_error then -- display given unit code with no error (for use with {{val}})
in_unit_table = '' -- suppress error message and prevent processing of output unit
end
in_unit_table = setmetatable({
symbol = in_unit, name2 = in_unit, utype = in_unit,
scale = 1, default = '', defkey = '', linkey = '',
bad_mcode = in_unit_table }, unit_mt)
end
in_unit_table.valinfo = valinfo
end
if parms.test == 'msg' then
-- Am testing the messages produced when no output unit is specified, and
-- the input unit has a missing or invalid default.
-- Set two units for testing that.
-- LATER: Remove this code.
if in_unit == 'chain' then
in_unit_table.default = nil -- no default
elseif in_unit == 'rd' then
in_unit_table.default = "ft!X!m" -- an invalid expression
end
end
in_unit_table.inout = 'in' -- this is an input unit
if not parms.range then
local success, inext, composite_unit = get_composite(parms, i, in_unit_table)
if not success then return false, inext end
if composite_unit then
in_unit_table = composite_unit
i = inext
end
end
if in_unit_table.builtin == 'mach' then
-- As with old template, a number following Mach as the input unit is the altitude,
-- and there is no way to specify an altitude for the output unit.
-- Could put more code in this function to get any output unit and check for
-- an altitude following that unit.
local success, info = extract_number(parms, parms[i], false, true)
if success then
i = i + 1
in_unit_table.altitude = info.value
end
end
local word = strip(parms[i])
i = i + 1
local precision, is_bad_precision
local function set_precision(text)
local number, is_integer = get_number(text)
if number then
if is_integer then
precision = number
else
precision = text
is_bad_precision = true
end
return true -- text was used for precision, good or bad
end
end
if word and not set_precision(word) then
parms.out_unit = parms.out_unit or word
if set_precision(strip(parms[i])) then
i = i + 1
end
end
if parms.opt_adj_mid then
word = parms[i]
i = i + 1
if word then -- mid-text words
if word:sub(1, 1) == '-' then
parms.mid = word
else
parms.mid = ' ' .. word
end
end
end
if parms.opt_one_preunit then
parms[parms.opt_flip and 'preunit2' or 'preunit1'] = preunits(1, parms[i])
i = i + 1
end
if parms.disp == 'x' then
-- Following is reasonably compatible with the old template.
local first = parms[i] or ''
local second = parms[i+1] or ''
i = i + 2
if strip(first) == '' then -- user can enter '&#32;' rather than ' ' to avoid the default
first = ' [&nbsp;' .. first
second = '&nbsp;]' .. second
end
parms.joins = { first, second }
elseif parms.opt_two_preunits then
local p1, p2 = preunits(2, parms[i], parms[i+1])
i = i + 2
if parms.preunit1 then
-- To simplify documentation, allow unlikely use of adj=pre with disp=preunit
-- (however, an output unit must be specified with adj=pre and with disp=preunit).
parms.preunit1 = parms.preunit1 .. p1
parms.preunit2 = p2
else
parms.preunit1, parms.preunit2 = p1, p2
end
end
if precision == nil then
if set_precision(strip(parms[i])) then
i = i + 1
end
end
if is_bad_precision then
add_warning(parms, 1, 'cvt_bad_prec', precision)
else
parms.precision = precision
end
return true, in_unit_table
end

local function record_default_precision(parms, out_current, precision)
-- If necessary, adjust parameters and return a possibly adjusted precision.
-- When converting a range of values where a default precision is required,
-- that default is calculated for each value because the result sometimes
-- depends on the precise input and output values. This function may cause
-- the entire convert process to be repeated in order to ensure that the
-- same default precision is used for each individual convert.
-- If that were not done, a range like 1000 to 1000.4 may give poor results
-- because the first output could be heavily rounded, while the second is not.
-- For range 1000.4 to 1000, this function can give the second convert the
-- same default precision that was used for the first.
if not parms.opt_round_each then
local maxdef = out_current.max_default_precision
if maxdef then
if maxdef < precision then
parms.do_convert_again = true
out_current.max_default_precision = precision
else
precision = out_current.max_default_precision
end
else
out_current.max_default_precision = precision
end
end
return precision
end

local function default_precision(parms, invalue, inclean, denominator, outvalue, in_current, out_current, extra)
-- Return a default value for precision (an integer like 2, 0, -2).
-- If denominator is not nil, it is the value of the denominator in inclean.
-- Code follows procedures used in old template.
local fudge = 1e-14 -- {{Order of magnitude}} adds this, so we do too
local prec, minprec, adjust
local subunit_ignore_trailing_zero
local subunit_more_precision -- kludge for "in" used in input like "|2|ft|6|in"
local composite = in_current.composite
if composite then
subunit_ignore_trailing_zero = true -- input "|2|st|10|lb" has precision 0, not -1
if composite[#composite].exception == 'subunit_more_precision' then
subunit_more_precision = true -- do not use standard precision with input like "|2|ft|6|in"
end
end
if denominator and denominator > 0 then
prec = math.max(log10(denominator), 1)
else
-- Count digits after decimal mark, handling cases like '12.345e6'.
local exponent
local integer, dot, decimals, expstr = inclean:match('^(%d*)(%.?)(%d*)(.*)')
local e = expstr:sub(1, 1)
if e == 'e' or e == 'E' then
exponent = tonumber(expstr:sub(2))
end
if dot == '' then
prec = subunit_ignore_trailing_zero and 0 or -integer:match('0*$'):len()
else
prec = #decimals
end
if exponent then
-- So '1230' and '1.23e3' both give prec = -1, and '0.00123' and '1.23e-3' give 5.
prec = prec - exponent
end
end
if in_current.istemperature and out_current.istemperature then
-- Converting between common temperatures (°C, °F, °R, K); not keVT.
-- Kelvin value can be almost zero, or small but negative due to precision problems.
-- Also, an input value like -300 C (below absolute zero) gives negative kelvins.
-- Calculate minimum precision from absolute value.
adjust = 0
local kelvin = abs((invalue - in_current.offset) * in_current.scale)
if kelvin < 1e-8 then -- assume nonzero due to input or calculation precision problem
minprec = 2
else
minprec = 2 - floor(log10(kelvin) + fudge) -- 3 sigfigs in kelvin
end
else
if invalue == 0 or outvalue <= 0 then
-- We are never called with a negative outvalue, but it might be zero.
-- This is special-cased to avoid calculation exceptions.
return record_default_precision(parms, out_current, 0)
end
if out_current.exception == 'integer_more_precision' and floor(invalue) == invalue then
-- With certain output units that sometimes give poor results
-- with default rounding, use more precision when the input
-- value is equal to an integer. An example of a poor result
-- is when input 50 gives a smaller output than input 49.5.
-- Experiment shows this helps, but it does not eliminate all
-- surprises because it is not clear whether "50" should be
-- interpreted as "from 45 to 55" or "from 49.5 to 50.5".
adjust = -log10(in_current.scale)
elseif subunit_more_precision then
-- Conversion like "{{convert|6|ft|1|in|cm}}" (where subunit is "in")
-- has a non-standard adjust value, to give more output precision.
adjust = log10(out_current.scale) + 2
else
adjust = log10(abs(invalue / outvalue))
end
adjust = adjust + log10(2)
-- Ensure that the output has at least two significant figures.
minprec = 1 - floor(log10(outvalue) + fudge)
end
if extra then
adjust = extra.adjust or adjust
minprec = extra.minprec or minprec
end
return record_default_precision(parms, out_current, math.max(floor(prec + adjust), minprec))
end

local function convert(parms, invalue, info, in_current, out_current)
-- Convert given input value from one unit to another.
-- Return output_value (a number) if a simple convert, or
-- return f, t where
-- f = true, t = table of information with results, or
-- f = false, t = error message table.
local inscale = in_current.scale
local outscale = out_current.scale
if not in_current.iscomplex and not out_current.iscomplex then
return invalue * (inscale / outscale) -- minimize overhead for most common case
end
if in_current.invert or out_current.invert then
-- Inverted units, such as inverse length, inverse time, or
-- fuel efficiency. Built-in units do not have invert set.
if (in_current.invert or 1) * (out_current.invert or 1) < 0 then
return 1 / (invalue * inscale * outscale)
end
return invalue * (inscale / outscale)
elseif in_current.offset then
-- Temperature (there are no built-ins for this type of unit).
if info.is_change then
return invalue * (inscale / outscale)
end
return (invalue - in_current.offset) * (inscale / outscale) + out_current.offset
else
-- Built-in unit.
local in_builtin = in_current.builtin
local out_builtin = out_current.builtin
if in_builtin and out_builtin then
if in_builtin == out_builtin then
return invalue
end
-- There are no cases (yet) where need to convert from one
-- built-in unit to another, so this should never occur.
return false, { 'cvt_bug_convert' }
end
if in_builtin == 'mach' or out_builtin == 'mach' then
local adjust
if in_builtin == 'mach' then
inscale = speed_of_sound(in_current.altitude)
adjust = outscale / 0.1
else
outscale = speed_of_sound(out_current.altitude)
adjust = 0.1 / inscale
end
return true, {
outvalue = invalue * (inscale / outscale),
adjust = log10(adjust) + log10(2),
}
elseif in_builtin == 'hand' then
-- 1 hand = 4 inches; 1.2 hands = 6 inches.
-- Decimals of a hand are only defined for the first digit, and
-- the first fractional digit should be a number of inches (1, 2 or 3).
-- However, this code interprets the entire fractional part as the number
-- of inches / 10 (so 1.75 inches would be 0.175 hands).
-- A value like 12.3 hands is exactly 12*4 + 3 inches; base default precision on that.
local integer, fracpart = math.modf(invalue)
local inch_value = 4 * integer + 10 * fracpart -- equivalent number of inches
local factor = inscale / outscale
if factor == 4 then
-- Am converting to inches: show exact result, and use "inches" not "in" by default.
if parms.abbr_org == nil then
out_current.usename = true
end
local show = format('%g', abs(inch_value)) -- show and clean are unsigned
if not show:find('e', 1, true) then
return true, {
invalue = inch_value,
outvalue = inch_value,
clean = show,
show = show,
}
end
end
local outvalue = (integer + 2.5 * fracpart) * factor
local fracstr = info.clean:match('%.(.*)') or ''
local fmt
if fracstr == '' then
fmt = '%.0f'
else
fmt = '%.' .. format('%d', #fracstr - 1) .. 'f'
end
return true, {
invalue = inch_value,
clean = format(fmt, inch_value),
outvalue = outvalue,
minprec = 0,
}
end
end
return false, { 'cvt_bug_convert' } -- should never occur
end

local function user_style(parms, i)
-- Return text for a user-specified style for a table cell, or '' if none,
-- given i = 1 (input style) or 2 (output style).
local style = parms[(i == 1) and 'stylein' or 'styleout']
if style then
style = style:gsub('"', '')
if style ~= '' then
if style:sub(-1) ~= ';' then
style = style .. ';'
end
return style
end
end
return ''
end

local function make_table_or_sort(parms, invalue, info, in_current, scaled_top)
-- Set options to handle output for a table or a sort key, or both.
-- The text sort key is based on the value resulting from converting
-- the input to a fake base unit with scale = 1, and other properties
-- required for a conversion derived from the input unit.
-- For other modules, return the sort key in a hidden span element, and
-- the scaled value used to generate the sort key.
-- If scaled_top is set, it is the scaled value of the numerator of a per unit
-- to be combined with this unit (the denominator) to make the sort key.
-- Scaling only works with units that convert with a factor (not temperature).
local sortkey, scaled_value
if parms.opt_sortable_on then
local base = { -- a fake unit with enough fields for a valid convert
scale = 1,
invert = in_current.invert and 1,
iscomplex = in_current.iscomplex,
offset = in_current.offset and 0,
}
local outvalue, extra = convert(parms, invalue, info, in_current, base)
if extra then
outvalue = extra.outvalue
end
if in_current.istemperature then
-- Have converted to kelvin; assume numbers close to zero have a
-- rounding error and should be zero.
if abs(outvalue) < 1e-12 then
outvalue = 0
end
end
if scaled_top and outvalue ~= 0 then
outvalue = scaled_top / outvalue
end
scaled_value = outvalue
if not valid_number(outvalue) then
if outvalue < 0 then
sortkey = '1000000000000000000'
else
sortkey = '9000000000000000000'
end
elseif outvalue == 0 then
sortkey = '5000000000000000000'
else
local mag = floor(log10(abs(outvalue)) + 1e-14)
local prefix
if outvalue > 0 then
prefix = 7000 + mag
else
prefix = 2999 - mag
outvalue = outvalue + 10^(mag+1)
end
sortkey = format('%d', prefix) .. format('%015.0f', floor(outvalue * 10^(14-mag)))
end
end
local sortspan
if sortkey and (parms.opt_sortable_debug or not parms.table_align) then
sortspan = parms.opt_sortable_debug and
'<span style="border:1px solid;display:inline;" class="sortkey">' .. sortkey .. '♠</span>' or
'<span style="display:none" class="sortkey">' .. sortkey .. '♠</span>'
parms.join_before = sortspan
end
if parms.table_align then
local style = 'style="text-align:' .. parms.table_align .. ';'
local sort = sortkey and ' data-sort-value="' .. sortkey .. '"' or ''
local joins = {}
for i = 1, 2 do
joins[i] = (i == 1 and '' or '\n|') .. style .. user_style(parms, i) .. '"' .. sort .. '|'
end
parms.table_joins = joins
end
return sortspan, scaled_value
end

local cvt_to_hand

local function cvtround(parms, info, in_current, out_current)
-- Return true, t where t is a table with the conversion results; fields:
-- show = rounded, formatted string with the result of converting value in info,
-- using the rounding specified in parms.
-- singular = true if result (after rounding and ignoring any negative sign)
-- is "1", or like "1.00", or is a fraction with value < 1;
-- (and more fields shown below, and a calculated 'absvalue' field).
-- or return false, t where t is an error message table.
-- Input info.clean uses en digits (it has been translated, if necessary).
-- Output show uses en or non-en digits as appropriate, or can be spelled.
if out_current.builtin == 'hand' then
return cvt_to_hand(parms, info, in_current, out_current)
end
local invalue = in_current.builtin == 'hand' and info.altvalue or info.value
local outvalue, extra = convert(parms, invalue, info, in_current, out_current)
if parms.need_table_or_sort then
parms.need_table_or_sort = nil -- process using first input value only
make_table_or_sort(parms, invalue, info, in_current)
end
if extra then
if not outvalue then return false, extra end
invalue = extra.invalue or invalue
outvalue = extra.outvalue
end
if not valid_number(outvalue) then
return false, { 'cvt_invalid_num' }
end
local isnegative
if outvalue < 0 then
isnegative = true
outvalue = -outvalue
end
local precision, show, exponent
local denominator = out_current.frac
if denominator then
show = fraction_table(outvalue, denominator)
else
precision = parms.precision
if not precision then
if parms.sigfig then
show, exponent = make_sigfig(outvalue, parms.sigfig)
elseif parms.opt_round then
local n = parms.opt_round
if n == 0.5 then
local integer, fracpart = math.modf(floor(2 * outvalue + 0.5) / 2)
if fracpart == 0 then
show = format('%.0f', integer)
else
show = format('%.1f', integer + fracpart)
end
else
show = format('%.0f', floor((outvalue / n) + 0.5) * n)
end
else
local inclean = info.clean
if extra then
inclean = extra.clean or inclean
show = extra.show
end
if not show then
precision = default_precision(parms, invalue, inclean, info.denominator, outvalue, in_current, out_current, extra)
end
end
end
end
if precision then
if precision >= 0 then
local fudge
if precision <= 8 then
-- Add a fudge to handle common cases of bad rounding due to inability
-- to precisely represent some values. This makes the following work:
-- {{convert|-100.1|C|K}} and {{convert|5555000|um|m|2}}.
-- Old template uses #expr round, which invokes PHP round().
-- LATER: Investigate how PHP round() works.
fudge = 2e-14
else
fudge = 0
end
local fmt = '%.' .. format('%d', precision) .. 'f'
local success
success, show = pcall(format, fmt, outvalue + fudge)
if not success then
return false, { 'cvt_big_prec', tostring(precision) }
end
else
precision = -precision -- #digits to zero (in addition to any digits after dot)
local shift = 10 ^ precision
show = format('%.0f', outvalue/shift)
if show ~= '0' then
exponent = #show + precision
end
end
end
local t = format_number(parms, show, exponent, isnegative)
if type(show) == 'string' then
-- Set singular using match because on some systems 0.99999999999999999 is 1.0.
if exponent then
t.singular = (exponent == 1 and show:match('^10*$'))
else
t.singular = (show == '1' or show:match('^1%.0*$'))
end
else
t.fraction_table = show
t.singular = (outvalue <= 1) -- cannot have 'fraction == 1', but if it were possible it would be singular
end
t.raw_absvalue = outvalue -- absolute value before rounding
return true, setmetatable(t, {
__index = function (self, key)
if key == 'absvalue' then
-- Calculate absolute value after rounding, if needed.
local clean, exponent = rawget(self, 'clean'), rawget(self, 'exponent')
local value = tonumber(clean) -- absolute value (any negative sign has been ignored)
if exponent then
value = value * 10^exponent
end
rawset(self, key, value)
return value
end
end })
end

function cvt_to_hand(parms, info, in_current, out_current)
-- Convert input to hands, inches.
-- Return true, t where t is a table with the conversion results;
-- or return false, t where t is an error message table.
if parms.abbr_org == nil then
out_current.usename = true -- default is to show name not symbol
end
local precision = parms.precision
local frac = out_current.frac
if not frac and precision and precision > 1 then
frac = (precision == 2) and 2 or 4
end
local out_next = out_current.out_next
if out_next then
-- Use magic knowledge to determine whether the next unit is inches without requiring i18n.
-- The following ensures that when the output combination "hand in" is used, the inches
-- value is rounded to match the hands value. Also, displaying say "61½" instead of 61.5
-- is better as 61.5 implies the value is not 61.4.
if out_next.exception == 'subunit_more_precision' then
out_next.frac = frac
end
end
-- Convert to inches; calculate hands from that.
local dummy_unit_table = { scale = out_current.scale / 4, frac = frac }
local success, outinfo = cvtround(parms, info, in_current, dummy_unit_table)
if not success then return false, outinfo end
local tfrac = outinfo.fraction_table
local inches = outinfo.raw_absvalue
if tfrac then
inches = floor(inches) -- integer part only; fraction added later
else
inches = floor(inches + 0.5) -- a hands measurement never shows decimals of an inch
end
local hands, inches = divide(inches, 4)
outinfo.absvalue = hands + inches/4 -- supposed to be the absolute rounded value, but this is close enough
local inchstr = tostring(inches) -- '0', '1', '2' or '3'
if precision and precision <= 0 then -- using negative or 0 for precision rounds to nearest hand
hands = floor(outinfo.raw_absvalue/4 + 0.5)
inchstr = ''
elseif tfrac then
-- Always show an integer before fraction (like "15.0½") because "15½" means 15-and-a-half hands.
inchstr = numdot .. format_fraction(parms, 'out', false, inchstr, tfrac.numstr, tfrac.denstr)
else
inchstr = numdot .. from_en(inchstr)
end
outinfo.show = outinfo.sign .. with_separator(parms, format('%.0f', hands)) .. inchstr
return true, outinfo
end

local function evaluate_condition(value, condition)
-- Return true or false from applying a conditional expression to value,
-- or throw an error if invalid.
-- A very limited set of expressions is supported:
-- v < 9
-- v * 9 < 9
-- where
-- 'v' is replaced with value
-- 9 is any number (as defined by Lua tonumber)
-- only en digits are accepted
-- '<' can also be '<=' or '>' or '>='
-- In addition, the following form is supported:
-- LHS and RHS
-- where
-- LHS, RHS = any of above expressions.
local function compare(value, text)
local arithop, factor, compop, limit = text:match('^%s*v%s*([*]?)(.-)([<>]=?)(.*)$')
if arithop == nil then
error('Invalid default expression', 0)
elseif arithop == '*' then
factor = tonumber(factor)
if factor == nil then
error('Invalid default expression', 0)
end
value = value * factor
end
limit = tonumber(limit)
if limit == nil then
error('Invalid default expression', 0)
end
if compop == '<' then
return value < limit
elseif compop == '<=' then
return value <= limit
elseif compop == '>' then
return value > limit
elseif compop == '>=' then
return value >= limit
end
error('Invalid default expression', 0) -- should not occur
end
local lhs, rhs = condition:match('^(.-%W)and(%W.*)')
if lhs == nil then
return compare(value, condition)
end
return compare(value, lhs) and compare(value, rhs)
end

local function get_default(value, unit_table)
-- Return true, s where s = name of unit's default output unit,
-- or return false, t where t is an error message table.
-- Some units have a default that depends on the input value
-- (the first value if a range of values is used).
-- If '!' is in the default, the first bang-delimited field is an
-- expression that uses 'v' to represent the input value.
-- Example: 'v < 120 ! small ! big ! suffix' (suffix is optional)
-- evaluates 'v < 120' as a boolean with result
-- 'smallsuffix' if (value < 120), or 'bigsuffix' otherwise.
-- Input must use en digits and '.' decimal mark.
local default = data_code.default_exceptions[unit_table.defkey or unit_table.symbol] or unit_table.default
if not default then
local per = unit_table.per
if per then
local function a_default(v, u)
local success, ucode = get_default(v, u)
if not success then
return '?' -- an unlikely error has occurred; will cause lookup of default to fail
end
-- Attempt to use only the first unit if a combination or output multiple.
-- This is not bulletproof but should work for most cases.
-- Where it does not work, the convert will need to specify the wanted output unit.
local t = all_units[ucode]
if t then
local combo = t.combination
if combo then
-- For a multiple like ftin, the "first" unit (ft) is last in the combination.
local i = t.multiple and table_len(combo) or 1
ucode = combo[i]
end
else
-- Try for an automatically generated combination.
local item = ucode:match('^(.-)%+') or ucode:match('^(%S+)%s')
if all_units[item] then
return item
end
end
return ucode
end
local unit1, unit2 = per[1], per[2]
local def1 = (unit1 and a_default(value, unit1) or unit_table.vprefix or '')
local def2 = a_default(1, unit2) -- 1 because per unit of denominator
return true, def1 .. '/' .. def2
end
return false, { 'cvt_no_default', unit_table.symbol }
end
if default:find('!', 1, true) == nil then
return true, default
end
local t = split(default, '!')
if #t == 3 or #t == 4 then
local success, result = pcall(evaluate_condition, value, t[1])
if success then
default = result and t[2] or t[3]
if #t == 4 then
default = default .. t[4]
end
return true, default
end
end
return false, { 'cvt_bad_default', unit_table.symbol }
end

local linked_pages -- to record linked pages so will not link to the same page more than once

local function unlink(unit_table)
-- Forget that the given unit has previously been linked (if it has).
-- That is needed when processing a range of inputs or outputs when an id
-- for the first range value may have been evaluated, but only an id for
-- the last value is displayed, and that id may need to be linked.
linked_pages[unit_table.unitcode or unit_table] = nil
end

local function make_link(link, id, unit_table)
-- Return wikilink "[[link|id]]", possibly abbreviated as in examples:
-- [[Mile|mile]] --> [[mile]]
-- [[Mile|miles]] --> [[mile]]s
-- However, just id is returned if:
-- * no link given (so caller does not need to check if a link was defined); or
-- * link has previously been used during the current convert (to avoid overlinking).
local link_key
if unit_table then
link_key = unit_table.unitcode or unit_table
else
link_key = link
end
if not link or link == '' or linked_pages[link_key] then
return id
end
linked_pages[link_key] = true
-- Following only works for language en, but it should be safe on other wikis,
-- and overhead of doing it generally does not seem worthwhile.
local l = link:sub(1, 1):lower() .. link:sub(2)
if link == id or l == id then
return '[[' .. id .. ']]'
elseif link .. 's' == id or l .. 's' == id then
return '[[' .. id:sub(1, -2) .. ']]s'
else
return '[[' .. link .. '|' .. id .. ']]'
end
end

local function variable_name(clean, unit_table)
-- For slwiki, a unit name depends on the value.
-- Parameter clean is the unsigned rounded value in en digits, as a string.
-- Value Source Example for "m"
-- integer 1: name1 meter (also is the name of the unit)
-- integer 2: var{1} metra
-- integer 3 and 4: var{2} metri
-- integer else: var{3} metrov (0 and 5 or more)
-- real/fraction: var{4} metra
-- var{i} means the i'th field in unit_table.varname if it exists and has
-- an i'th field, otherwise name2.
-- Fields are separated with "!" and are not empty.
-- A field for a unit using an SI prefix has the prefix name inserted,
-- replacing '#' if found, or before the field otherwise.
local vname
if clean == '1' then
vname = unit_table.name1
elseif unit_table.varname then
local i
if clean == '2' then
i = 1
elseif clean == '3' or clean == '4' then
i = 2
elseif clean:find('.', 1, true) then
i = 4
else
i = 3
end
if i > 1 and varname == 'pl' then
i = i - 1
end
vname = split(unit_table.varname, '!')[i]
end
if vname then
local si_name = rawget(unit_table, 'si_name') or ''
local pos = vname:find('#', 1, true)
if pos then
vname = vname:sub(1, pos - 1) .. si_name .. vname:sub(pos + 1)
else
vname = si_name .. vname
end
return vname
end
return unit_table.name2
end

local function linked_id(parms, unit_table, key_id, want_link, clean)
-- Return final unit id (symbol or name), optionally with a wikilink,
-- and update unit_table.sep if required.
-- key_id is one of: 'symbol', 'sym_us', 'name1', 'name1_us', 'name2', 'name2_us'.
local abbr_on = (key_id == 'symbol' or key_id == 'sym_us')
if abbr_on and want_link then
local symlink = rawget(unit_table, 'symlink')
if symlink then
return symlink -- for exceptions that have the linked symbol built-in
end
end
local multiplier = rawget(unit_table, 'multiplier')
local per = unit_table.per
if per then
local paren1, paren2 = '', '' -- possible parentheses around bottom unit
local unit1 = per[1] -- top unit_table, or nil
local unit2 = per[2] -- bottom unit_table
if abbr_on then
if not unit1 then
unit_table.sep = '' -- no separator in "$2/acre"
end
if not want_link then
local symbol = unit_table.symbol_raw
if symbol then
return symbol -- for exceptions that have the symbol built-in
end
end
if (unit2.symbol):find('⋅', 1, true) then
paren1, paren2 = '(', ')'
end
end
local key_id2 -- unit2 is always singular
if key_id == 'name2' then
key_id2 = 'name1'
elseif key_id == 'name2_us' then
key_id2 = 'name1_us'
else
key_id2 = key_id
end
local result
if abbr_on then
result = '/'
elseif omitsep then
result = per_word
elseif unit1 then
result = ' ' .. per_word .. ' '
else
result = per_word .. ' '
end
if want_link and unit_table.link then
if abbr_on or not varname then
result = (unit1 and linked_id(parms, unit1, key_id, false, clean) or '') .. result .. linked_id(parms, unit2, key_id2, false, '1')
else
result = (unit1 and variable_name(clean, unit1) or '') .. result .. variable_name('1', unit2)
end
if omit_separator(result) then
unit_table.sep = ''
end
return make_link(unit_table.link, result, unit_table)
end
if unit1 then
result = linked_id(parms, unit1, key_id, want_link, clean) .. result
if unit1.sep then
unit_table.sep = unit1.sep
end
elseif omitsep then
unit_table.sep = ''
end
return result .. paren1 .. linked_id(parms, unit2, key_id2, want_link, '1') .. paren2
end
if multiplier then
-- A multiplier (like "100" in "100km") forces the unit to be plural.
multiplier = from_en(multiplier)
if not omitsep then
multiplier = multiplier .. (abbr_on and '&nbsp;' or ' ')
end
if not abbr_on then
if key_id == 'name1' then
key_id = 'name2'
elseif key_id == 'name1_us' then
key_id = 'name2_us'
end
end
else
multiplier = ''
end
local id = unit_table.fixed_name or ((varname and not abbr_on) and variable_name(clean, unit_table) or unit_table[key_id])
if omit_separator(id) then
unit_table.sep = ''
end
if want_link then
local link = data_code.link_exceptions[unit_table.linkey or unit_table.symbol] or unit_table.link
if link then
local before = ''
local i = unit_table.customary
if i == 1 and parms.opt_sp_us then
i = 2 -- show "U.S." not "US"
end
if i == 3 and abbr_on then
i = 4 -- abbreviate "imperial" to "imp"
end
local customary = text_code.customary_units[i]
if customary then
-- LATER: This works for language en only, but it's esoteric so ignore for now.
local pertext
if id:sub(1, 1) == '/' then
-- Want unit "/USgal" to display as "/U.S. gal", not "U.S. /gal".
pertext = '/'
id = id:sub(2)
elseif id:sub(1, 4) == 'per ' then
-- Similarly want "per U.S. gallon", not "U.S. per gallon" (but in practice this is unlikely to be used).
pertext = 'per '
id = id:sub(5)
else
pertext = ''
end
-- Omit any "US"/"U.S."/"imp"/"imperial" from start of id since that will be inserted.
local removes = (i < 3) and { 'US&nbsp;', 'US ', 'U.S.&nbsp;', 'U.S. ' } or { 'imp&nbsp;', 'imp ', 'imperial ' }
for _, prefix in ipairs(removes) do
local plen = #prefix
if id:sub(1, plen) == prefix then
id = id:sub(plen + 1)
break
end
end
before = pertext .. make_link(customary.link, customary[1]) .. ' '
end
id = before .. make_link(link, id, unit_table)
end
end
return multiplier .. id
end

local function make_id(parms, which, unit_table)
-- Return id, f where
-- id = unit name or symbol, possibly modified
-- f = true if id is a name, or false if id is a symbol
-- using the value for index 'which', and for 'in' or 'out' (unit_table.inout).
-- Result is '' if no symbol/name is to be used.
-- In addition, set unit_table.sep = ' ' or '&nbsp;' or ''
-- (the separator that caller will normally insert before the id).
if parms.opt_values then
unit_table.sep = ''
return ''
end
local inout = unit_table.inout
local info = unit_table.valinfo[which]
local abbr_org = parms.abbr_org
local adjectival = parms.opt_adjectival
local lk = parms.lk
local want_link = (lk == 'on' or lk == inout)
local usename = unit_table.usename
local singular = info.singular
local want_name
if usename then
want_name = true
else
if abbr_org == nil then
if parms.wantname then
want_name = true
end
if unit_table.usesymbol then
want_name = false
end
end
if want_name == nil then
local abbr = parms.abbr
if abbr == 'on' or abbr == inout or (abbr == 'mos' and inout == 'out') then
want_name = false
else
want_name = true
end
end
end
local key
if want_name then
if lk == nil and unit_table.builtin == 'hand' then
want_link = true
end
if parms.opt_use_nbsp then
unit_table.sep = '&nbsp;'
else
unit_table.sep = ' '
end
if parms.opt_singular then
local value
if inout == 'in' then
value = info.value
else
value = info.absvalue
end
if value then -- some unusual units do not always set value field
value = abs(value)
singular = (0 < value and value < 1.0001)
end
end
if unit_table.engscale then
-- engscale: so "|1|e3kg" gives "1 thousand kilograms" (plural)
singular = false
end
key = (adjectival or singular) and 'name1' or 'name2'
if parms.opt_sp_us then
key = key .. '_us'
end
else
if unit_table.builtin == 'hand' then
if parms.opt_hand_hh then
unit_table.symbol = 'hh' -- LATER: might want i18n applied to this
end
end
unit_table.sep = '&nbsp;'
key = parms.opt_sp_us and 'sym_us' or 'symbol'
end
return linked_id(parms, unit_table, key, want_link, info.clean), want_name
end

local function decorate_value(parms, unit_table, which, number_word)
-- If needed, update unit_table so values will be shown with extra information.
-- For consistency with the old template (but different from fmtpower),
-- the style to display powers of 10 includes "display:none" to allow some
-- browsers to copy, for example, "10³" as "10^3", rather than as "103".
local info
local engscale = unit_table.engscale
local prefix = unit_table.vprefix
if engscale or prefix then
info = unit_table.valinfo[which]
if info.decorated then
return -- do not redecorate if repeating convert
end
info.decorated = true
if engscale then
local inout = unit_table.inout
local abbr = parms.abbr
if (abbr == 'on' or abbr == inout) and not parms.number_word then
info.show = info.show ..
'<span style="margin-left:0.2em">×<span style="margin-left:0.1em">' ..
from_en('10') ..
'</span></span><s style="display:none">^</s><sup>' ..
from_en(tostring(engscale.exponent)) .. '</sup>'
elseif number_word then
local number_id
local lk = parms.lk
if lk == 'on' or lk == inout then
number_id = make_link(engscale.link, engscale[1])
else
number_id = engscale[1]
end
-- WP:NUMERAL recommends "&nbsp;" in values like "12 million".
info.show = info.show .. (parms.opt_adjectival and '-' or '&nbsp;') .. number_id
end
end
if prefix then
info.show = prefix .. info.show
end
end
end

local function process_input(parms, in_current)
-- Processing required once per conversion.
-- Return block of text to represent input (value/unit).
if parms.opt_output_only or parms.opt_output_number_only or parms.opt_output_unit_only then
parms.joins = { '', '' }
return ''
end
local first_unit
local composite = in_current.composite -- nil or table of units
if composite then
first_unit = composite[1]
else
first_unit = in_current
end
local id1, want_name = make_id(parms, 1, first_unit)
local sep = first_unit.sep -- separator between value and unit, set by make_id
local preunit = parms.preunit1
if preunit then
sep = '' -- any separator is included in preunit
else
preunit = ''
end
if parms.opt_input_unit_only then
parms.joins = { '', '' }
if composite then
local parts = { id1 }
for i, unit in ipairs(composite) do
if i > 1 then
table.insert(parts, (make_id(parms, 1, unit)))
end
end
id1 = table.concat(parts, ' ')
end
if want_name and parms.opt_adjectival then
return preunit .. hyphenated(id1)
end
return preunit .. id1
end
if parms.opt_also_symbol and not composite then
local join1 = parms.joins[1]
if join1 == ' (' or join1 == ' [' then
parms.joins = { ' [' .. first_unit[parms.opt_sp_us and 'sym_us' or 'symbol'] .. ']' .. join1 , parms.joins[2] }
end
end
if in_current.builtin == 'mach' and first_unit.sep ~= '' then -- '' means omitsep with non-enwiki name
local prefix = id1 .. '&nbsp;'
local range = parms.range
local valinfo = first_unit.valinfo
local result = prefix .. valinfo[1].show
if range then
-- For simplicity and because more not needed, handle one range item only.
local prefix2 = make_id(parms, 2, first_unit) .. '&nbsp;'
result = range_text(range[1], want_name, parms, result, prefix2 .. valinfo[2].show, 'in')
end
return preunit .. result
end
if composite then
-- Simplify: assume there is no range, and no decoration.
local mid = (not parms.opt_flip) and parms.mid or ''
local sep1 = '&nbsp;'
local sep2 = ' '
if parms.opt_adjectival and want_name then
sep1 = '-'
sep2 = '-'
end
if omitsep and sep == '' then
-- Testing the id of the most significant unit should be sufficient.
sep1 = ''
sep2 = ''
end
local parts = { first_unit.valinfo[1].show .. sep1 .. id1 }
for i, unit in ipairs(composite) do
if i > 1 then
table.insert(parts, unit.valinfo[1].show .. sep1 .. (make_id(parms, 1, unit)))
end
end
return table.concat(parts, sep2) .. mid
end
local add_unit = (parms.abbr == 'mos') or
parms[parms.opt_flip and 'out_range_x' or 'in_range_x'] or
(not want_name and parms.abbr_range_x)
local range = parms.range
if range and not add_unit then
unlink(first_unit)
end
local id = range and make_id(parms, range.n + 1, first_unit) or id1
local extra, was_hyphenated = hyphenated_maybe(parms, want_name, sep, id, 'in')
if was_hyphenated then
add_unit = false
end
local result
local valinfo = first_unit.valinfo
if range then
for i = 0, range.n do
local number_word
if i == range.n then
add_unit = false
number_word = true
end
decorate_value(parms, first_unit, i+1, number_word)
local show = valinfo[i+1].show
if add_unit then
show = show .. first_unit.sep .. (i == 0 and id1 or make_id(parms, i+1, first_unit))
end
if i == 0 then
result = show
else
result = range_text(range[i], want_name, parms, result, show, 'in')
end
end
else
decorate_value(parms, first_unit, 1, true)
result = valinfo[1].show
end
return result .. preunit .. extra
end

local function process_one_output(parms, out_current)
-- Processing required for each output unit.
-- Return block of text to represent output (value/unit).
local inout = out_current.inout -- normally 'out' but can be 'in' for order=out
local id1, want_name = make_id(parms, 1, out_current)
local sep = out_current.sep -- set by make_id
local preunit = parms.preunit2
if preunit then
sep = '' -- any separator is included in preunit
else
preunit = ''
end
if parms.opt_output_unit_only then
if want_name and parms.opt_adjectival then
return preunit .. hyphenated(id1)
end
return preunit .. id1
end
if out_current.builtin == 'mach' and out_current.sep ~= '' then -- '' means omitsep with non-enwiki name
local prefix = id1 .. '&nbsp;'
local range = parms.range
local valinfo = out_current.valinfo
local result = prefix .. valinfo[1].show
if range then
-- For simplicity and because more not needed, handle one range item only.
result = range_text(range[1], want_name, parms, result, prefix .. valinfo[2].show, inout)
end
return preunit .. result
end
local add_unit = (parms[parms.opt_flip and 'in_range_x' or 'out_range_x'] or
(not want_name and parms.abbr_range_x)) and
not parms.opt_output_number_only
local range = parms.range
if range and not add_unit then
unlink(out_current)
end
local id = range and make_id(parms, range.n + 1, out_current) or id1
local extra, was_hyphenated = hyphenated_maybe(parms, want_name, sep, id, inout)
if was_hyphenated then
add_unit = false
end
local result
local valinfo = out_current.valinfo
if range then
for i = 0, range.n do
local number_word
if i == range.n then
add_unit = false
number_word = true
end
decorate_value(parms, out_current, i+1, number_word)
local show = valinfo[i+1].show
if add_unit then
show = show .. out_current.sep .. (i == 0 and id1 or make_id(parms, i+1, out_current))
end
if i == 0 then
result = show
else
result = range_text(range[i], want_name, parms, result, show, inout)
end
end
else
decorate_value(parms, out_current, 1, true)
result = valinfo[1].show
end
if parms.opt_output_number_only then
return result
end
return result .. preunit .. extra
end

local function make_output_single(parms, in_unit_table, out_unit_table)
-- Return true, item where item = wikitext of the conversion result
-- for a single output (which is not a combination or a multiple);
-- or return false, t where t is an error message table.
if parms.opt_order_out and in_unit_table.unitcode == out_unit_table.unitcode then
out_unit_table.valinfo = in_unit_table.valinfo
else
out_unit_table.valinfo = collection()
for _, v in ipairs(in_unit_table.valinfo) do
local success, info = cvtround(parms, v, in_unit_table, out_unit_table)
if not success then return false, info end
out_unit_table.valinfo:add(info)
end
end
return true, process_one_output(parms, out_unit_table)
end

local function make_output_multiple(parms, in_unit_table, out_unit_table)
-- Return true, item where item = wikitext of the conversion result
-- for an output which is a multiple (like 'ftin');
-- or return false, t where t is an error message table.
local inout = out_unit_table.inout -- normally 'out' but can be 'in' for order=out
local multiple = out_unit_table.multiple -- table of scaling factors (will not be nil)
local combos = out_unit_table.combination -- table of unit tables (will not be nil)
local abbr = parms.abbr
local abbr_org = parms.abbr_org
local disp = parms.disp
local want_name = (abbr_org == nil and (disp == 'or' or disp == 'slash')) or
not (abbr == 'on' or abbr == inout or abbr == 'mos')
local want_link = (parms.lk == 'on' or parms.lk == inout)
local mid = parms.opt_flip and parms.mid or ''
local sep1 = '&nbsp;'
local sep2 = ' '
if parms.opt_adjectival and want_name then
sep1 = '-'
sep2 = '-'
end
local do_spell = parms.opt_spell_out
parms.opt_spell_out = nil -- so the call to cvtround does not spell the value
local function make_result(info, isfirst)
local fmt, outvalue, sign
local results = {}
for i = 1, #combos do
local tfrac, thisvalue, strforce
local out_current = combos[i]
out_current.inout = inout
local scale = multiple[i]
if i == 1 then -- least significant unit ('in' from 'ftin')
local decimals
out_current.frac = out_unit_table.frac
local success, outinfo = cvtround(parms, info, in_unit_table, out_current)
if not success then return false, outinfo end
if isfirst then
out_unit_table.valinfo = { outinfo } -- in case output value of first least significant unit is needed
end
sign = outinfo.sign
tfrac = outinfo.fraction_table
if outinfo.is_scientific then
strforce = outinfo.show
decimals = ''
elseif tfrac then
decimals = ''
else
local show = outinfo.show -- number as a string in local language
local p1, p2 = show:find(numdot, 1, true)
decimals = p1 and show:sub(p2 + 1) or '' -- text after numdot, if any
end
fmt = '%.' .. ulen(decimals) .. 'f' -- to reproduce precision
if decimals == '' then
if tfrac then
outvalue = floor(outinfo.raw_absvalue) -- integer part only; fraction added later
else
outvalue = floor(outinfo.raw_absvalue + 0.5) -- keep all integer digits of least significant unit
end
else
outvalue = outinfo.absvalue
end
end
if scale then
outvalue, thisvalue = divide(outvalue, scale)
else
thisvalue = outvalue
end
local id
if want_name then
if varname then
local clean
if strforce or tfrac then
clean = '.1' -- dummy value to force name for floating point
else
clean = format(fmt, thisvalue)
end
id = variable_name(clean, out_current)
else
local key = 'name2'
if parms.opt_adjectival then
key = 'name1'
elseif tfrac then
if thisvalue == 0 then
key = 'name1'
end
elseif parms.opt_singular then
if 0 < thisvalue and thisvalue < 1.0001 then
key = 'name1'
end
else
if thisvalue == 1 then
key = 'name1'
end
end
id = out_current[key]
end
else
id = out_current['symbol']
end
if i == 1 and omit_separator(id) then
-- Testing the id of the least significant unit should be sufficient.
sep1 = ''
sep2 = ''
end
if want_link then
local link = out_current.link
if link then
id = make_link(link, id, out_current)
end
end
local strval
local spell_inout = (i == #combos or outvalue == 0) and inout or '' -- trick so the last value processed (first displayed) has uppercase, if requested
if strforce and outvalue == 0 then
sign = '' -- any sign is in strforce
strval = strforce -- show small values in scientific notation; will only use least significant unit
elseif tfrac then
local wholestr = (thisvalue > 0) and tostring(thisvalue) or nil
strval = format_fraction(parms, spell_inout, false, wholestr, tfrac.numstr, tfrac.denstr, do_spell)
else
strval = (thisvalue == 0) and from_en('0') or with_separator(parms, format(fmt, thisvalue))
if do_spell then
strval = spell_number(parms, spell_inout, strval) or strval
end
end
table.insert(results, strval .. sep1 .. id)
if outvalue == 0 then
break
end
fmt = '%.0f' -- only least significant unit can have a non-integral value
end
local reversed, count = {}, #results
for i = 1, count do
reversed[i] = results[count + 1 - i]
end
return true, sign .. table.concat(reversed, sep2)
end
local valinfo = in_unit_table.valinfo
local success, result = make_result(valinfo[1], true)
if not success then return false, result end
local range = parms.range
if range then
for i = 1, range.n do
local success, result2 = make_result(valinfo[i+1])
if not success then return false, result2 end
result = range_text(range[i], want_name, parms, result, result2, inout)
end
end
return true, result .. mid
end

local function process(parms, in_unit_table, out_unit_table)
-- Return true, s, outunit where s = final wikitext result,
-- or return false, t where t is an error message table.
linked_pages = {}
local success, bad_output
local bad_input_mcode = in_unit_table.bad_mcode -- nil if input unit is a valid convert unit
local out_unit = parms.out_unit
if out_unit == nil or out_unit == '' or type(out_unit) == 'function' then
if bad_input_mcode or parms.opt_input_unit_only then
bad_output = ''
else
local getdef = type(out_unit) == 'function' and out_unit or get_default
success, out_unit = getdef(in_unit_table.valinfo[1].value, in_unit_table)
parms.out_unit = out_unit
if not success then
bad_output = out_unit
end
end
end
if not bad_output and not out_unit_table then
success, out_unit_table = lookup(parms, out_unit, 'any_combination')
if success then
local mismatch = check_mismatch(in_unit_table, out_unit_table)
if mismatch then
bad_output = mismatch
end
else
bad_output = out_unit_table
end
end
local lhs, rhs
local flipped = parms.opt_flip and not bad_input_mcode
if bad_output then
rhs = (bad_output == '') and '' or message(parms, bad_output)
elseif parms.opt_input_unit_only then
rhs = ''
else
local combos -- nil (for 'ft' or 'ftin'), or table of unit tables (for 'm ft')
if not out_unit_table.multiple then -- nil/false ('ft' or 'm ft'), or table of factors ('ftin')
combos = out_unit_table.combination
end
local frac = parms.frac -- nil or denominator of fraction for output values
if frac then
-- Apply fraction to the unit (if only one), or to non-SI units (if a combination),
-- except that if a precision is also specified, the fraction only applies to
-- the hand unit; that allows the following result:
-- {{convert|156|cm|in hand|1|frac=2}} → 156 centimetres (61.4 in; 15.1½ hands)
-- However, the following is handled elsewhere as a special case:
-- {{convert|156|cm|hand in|1|frac=2}} → 156 centimetres (15.1½ hands; 61½ in)
if combos then
local precision = parms.precision
for _, unit in ipairs(combos) do
if unit.builtin == 'hand' or (not precision and not unit.prefixes) then
unit.frac = frac
end
end
else
out_unit_table.frac = frac
end
end
local outputs = {}
local imax = combos and #combos or 1 -- 1 (single unit) or number of unit tables
if imax == 1 then
parms.opt_order_out = nil -- only useful with an output combination
end
if not flipped and not parms.opt_order_out then
-- Process left side first so any duplicate links (from lk=on) are suppressed
-- on right. Example: {{convert|28|e9pc|e9ly|abbr=off|lk=on}}
lhs = process_input(parms, in_unit_table)
end
for i = 1, imax do
local success, item
local out_current = combos and combos[i] or out_unit_table
out_current.inout = 'out'
if i == 1 then
if imax > 1 and out_current.builtin == 'hand' then
out_current.out_next = combos[2] -- built-in hand can influence next unit in a combination
end
if parms.opt_order_out then
out_current.inout = 'in'
end
end
if out_current.multiple then
success, item = make_output_multiple(parms, in_unit_table, out_current)
else
success, item = make_output_single(parms, in_unit_table, out_current)
end
if not success then return false, item end
outputs[i] = item
end
if parms.opt_order_out then
lhs = outputs[1]
table.remove(outputs, 1)
end
local sep = parms.table_joins and parms.table_joins[2] or parms.join_between
rhs = table.concat(outputs, sep)
end
if flipped or not lhs then
local input = process_input(parms, in_unit_table)
if flipped then
lhs = rhs
rhs = input
else
lhs = input
end
end
if parms.join_before then
lhs = parms.join_before .. lhs
end
local wikitext
if bad_input_mcode then
if bad_input_mcode == '' then
wikitext = lhs
else
wikitext = lhs .. message(parms, bad_input_mcode)
end
elseif parms.table_joins then
wikitext = parms.table_joins[1] .. lhs .. parms.table_joins[2] .. rhs
else
wikitext = lhs .. parms.joins[1] .. rhs .. parms.joins[2]
end
if parms.warnings and not bad_input_mcode then
wikitext = wikitext .. parms.warnings
end
return true, wikitext, out_unit_table
end

local function main_convert(frame)
-- Do convert, and if needed, do it again with higher default precision.
local parms = { frame = frame } -- will hold template arguments, after translation
set_config(frame.args)
local success, result = get_parms(parms, frame:getParent().args)
if success then
if type(result) ~= 'table' then
return tostring(result)
end
local in_unit_table = result
local out_unit_table
for _ = 1, 2 do -- use counter so cannot get stuck repeating convert
success, result, out_unit_table = process(parms, in_unit_table, out_unit_table)
if success and parms.do_convert_again then
parms.do_convert_again = false
else
break
end
end
end
-- If input=x gives a problem, the result should be just the user input
-- (if x is a property like P123 it has been replaced with '').
-- An unknown input unit would display the input and an error message
-- with success == true at this point.
-- Also, can have success == false with a message that outputs an empty string.
if parms.input_text then
if success and not parms.have_problem then
return result
end
local cat
if parms.tracking then
-- Add a tracking category using the given text as the category sort key.
-- There is currently only one type of tracking, but in principle multiple
-- items could be tracked, using different sort keys for convenience.
cat = wanted_category('tracking', parms.tracking)
end
return parms.input_text .. (cat or '')
end
return success and result or message(parms, result)
end


return ret
local function _unit(unitcode, options)
-- Helper function for Module:Val to look up a unit.
-- Parameter unitcode must be a string to identify the wanted unit.
-- Parameter options must be nil or a table with optional fields:
-- value = number (for sort key; default value is 1)
-- scaled_top = nil for a normal unit, or a number for a unit which is
-- the denominator of a per unit (for sort key)
-- si = { 'symbol', 'link' }
-- (a table with two strings) to make an SI unit
-- that will be used for the look up
-- link = true if result should be [[linked]]
-- sort = 'on' or 'debug' if result should include a sort key in a
-- span element ('debug' makes the key visible)
-- name = true for the name of the unit instead of the symbol
-- us = true for the US spelling of the unit, if any
-- Return nil if unitcode is not a non-empty string.
-- Otherwise return a table with fields:
-- text = requested symbol or name of unit, optionally linked
-- scaled_value = input value adjusted by unit scale; used for sort key
-- sortspan = span element with sort key like that provided by {{ntsh}},
-- calculated from the result of converting value
-- to a base unit with scale 1.
-- unknown = true if the unitcode was not known
unitcode = strip(unitcode)
if unitcode == nil or unitcode == '' then
return nil
end
set_config({})
linked_pages = {}
options = options or {}
local parms = {
abbr = options.name and 'off' or 'on',
lk = options.link and 'on' or nil,
opt_sp_us = options.us and true or nil,
opt_ignore_error = true, -- do not add pages using this function to 'what links here' for Module:Convert/extra
opt_sortable_on = options.sort == 'on' or options.sort == 'debug',
opt_sortable_debug = options.sort == 'debug',
}
if options.si then
-- Make a dummy table of units (just one unit) for lookup to use.
-- This makes lookup recognize any SI prefix in the unitcode.
local symbol = options.si[1] or '?'
parms.unittable = { [symbol] = {
_name1 = symbol,
_name2 = symbol,
_symbol = symbol,
utype = symbol,
scale = symbol == 'g' and 0.001 or 1,
prefixes = 1,
default = symbol,
link = options.si[2],
}}
end
local success, unit_table = lookup(parms, unitcode, 'no_combination')
if not success then
unit_table = setmetatable({
symbol = unitcode, name2 = unitcode, utype = unitcode,
scale = 1, default = '', defkey = '', linkey = '' }, unit_mt)
end
local value = tonumber(options.value) or 1
local clean = tostring(abs(value))
local info = {
value = value,
altvalue = value,
singular = (clean == '1'),
clean = clean,
show = clean,
}
unit_table.inout = 'in'
unit_table.valinfo = { info }
local sortspan, scaled_value
if options.sort then
sortspan, scaled_value = make_table_or_sort(parms, value, info, unit_table, options.scaled_top)
end
return {
text = make_id(parms, 1, unit_table),
sortspan = sortspan,
scaled_value = scaled_value,
unknown = not success and true or nil,
}
end
end


return p
return { convert = main_convert, _unit = _unit }

Revision as of 15:00, 18 January 2018

local p = {}

function p.factor(frame)
	-- Consider calling the parser function #expr
	--   to simplify a potential mathematical expression?
    number = tonumber(frame.args[1])
    if number == nil then
    	return '<strong class="error">Error: input not recognized as a number</strong>'
    end

    productSymbol = frame.args['product'] or '·'
    bold = frame.args['bold'] and true
    big = frame.args['big'] and true
    serif = frame.args['serif'] and true
    primeLink = frame.args['prime'] and true

    number = math.floor(number)
    if number < 2 or number > 1000000000 or number == math.huge then
        return '<strong class="error">Error: ' .. number .. ' out of range</strong>'
    end

    result = ""
    currentNumber = number
    power = 0
    divisor = 2

    -- Attempt factoring by the value of the divisor
    --   divisor increments by 2, except first iteration (2 to 3)
    while divisor <= math.sqrt(currentNumber) do
        power = 0
        while currentNumber % divisor == 0 do
            currentNumber = currentNumber / divisor
            power = power + 1
        end

		-- Concat result and increment divisor
		-- when divisor is 2, go to 3. All other times, add 2
		result = result .. powerformat(divisor, power, productSymbol)
        divisor = divisor + (divisor == 2 and 1 or 2)
    end

    if currentNumber ~= 1 then
        result = result .. currentNumber .. ' ' .. productSymbol .. ' '
    end

    if currentNumber == number and primeLink then
        return '[[prime number|prime]]'
    end

    result = string.sub(result,1,-4)

    return format(result)
end

function powerformat(divisor, power, productSymbol)
	if power < 1      then return ''
    elseif power == 1 then return divisor .. ' ' .. productSymbol .. ' '
    else return divisor .. '<sup>' .. power .. '</sup>' .. productSymbol .. ' '
    end
end

function format(numString)
    if bold then
    	numString = '<b>'..numString..'</b>'
    end

	ret = (serif or big) and '<span ' or ''
	if serif then ret = ret .. 'class="texhtml" ' end
	if big   then ret = ret .. 'style="font-size:165%" ' end
	ret = ret .. ((serif or big) and '>' or '') .. numString .. '</span>'

    return ret
end

return p
Retrieved from "https://en.wikipedia.org/w/index.php?title=Module:Factorization&oldid=821122884"