--
-- Converts numbers to a specified base between 2 and 36, for use in
-- templates such as {{binary}}, {{octal}}, {{hexadecimal}}, etc.
--
-- from - the base of the input. Defaults to 10 (or 16 if the input has a
-- leading '0x'). Note that bases other than 10 are not supported if the
-- input has a fractional part.
-- precision - number of digits to be rendered after the radix point. Trailing
-- zeros will be added if needed. If not specified, however many digits are
-- needed will be shown, up to 10.
-- width - minimum number of digits to be rendered before the radix point.
-- Leading zeros will be added if needed.
--
local p = {}
local digits = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'
function p._convert(n, base, from, precision, width)
n = '' .. n -- convert to a string
-- strip off any leading '0x' (unless x is a valid digit in the input base)
from = tonumber(from)
if not from or from < 34 then
local c
n, c = n:gsub('^(-?)0[Xx]', '%1')
if c > 0 and not from then from = 16 end
end
-- check for a negative sign. Do this while the input is still in string form,
-- because tonumber doesn't support negative numbers in non-10 bases.
local sign = ''
local c
n, c = n:gsub('^-', '')
if c > 0 then sign = '-' end
from = from or 10
local num = tonumber(n, from)
base = tonumber(base)
precision = tonumber(precision)
width = tonumber(width)
if not num or not base then return n end
local i, f = math.modf(num)
local t = {}
repeat
local d = (i % base) + 1
i = math.floor(i / base)
table.insert(t, 1, digits:sub(d, d))
until i == 0
while #t < (width or 0) do
table.insert(t, 1, '0')
end
local intPart = table.concat(t, '')
-- compute the fractional part
local tf = {}
while f > 0 and #tf < (precision or 10) do
f = f * base
i, f = math.modf(f)
table.insert(tf, digits:sub(i + 1, i + 1))
end
-- add trailing zeros if needed
if precision and #tf < precision then
for i = 1, precision - #tf do
table.insert(tf, '0')
end
end
fracPart = table.concat(tf, '')
-- remove trailing zeros if not needed
if not precision then
fracPart = fracPart:gsub('0*$', '')
end
-- add the radix point if needed
if #fracPart > 0 then
fracPart = '.' .. fracPart
end
return sign .. intPart .. fracPart
end
function p.convert(frame)
local n = frame.args.n
local base = frame.args.base
local from = frame.args.from
local precision = frame.args.precision
local width = frame.args.width
return p._convert(n, base, from, precision, width)
end
return p
