Module:BaseConvert
Converts numbers to a specified base between 2 and 36, for use in templates such as {{binary}}, {{octal}}, {{hexadecimal}}, etc.
Example usage:
local BaseConvert = require('Module:BaseConvert')
BaseConvert.convert({n = 14600926, base = 16}) -- returns 'DECADE'
Arguments:
- n - (required) the number to be converted, as a string. It may be a number instead, if the input base is 10.
- base - (required) the base to which the number should be converted. May be between 2 and 36, inclusive.
- 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.
- default - Value to return if n is empty or non-numeric. Defaults to the value of n.
- prefix / suffix - wikitext to add before/after the returned result. Will not be added if n is empty or non-numeric. For example, you might use a prefix of
0xwhen converting to hex, or a suffix of<sub>8</sub>when converting to octal.
local p = {}
local digits = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'
function normalizeFullWidthChars(s)
return mw.ustring.gsub(s, '[！-～]', function(s)
return mw.ustring.char(mw.ustring.codepoint(s, 1) - 0xFEE0)
end)
end
function _convert(n, base, from, precision, width, default, prefix, suffix)
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
-- replace any full-width Unicode characters in the string with their ASCII equivalents
n = normalizeFullWidthChars(n)
-- handle scientific notation with whitespace around the 'e' e.g. '5 e7'
n = n:gsub('%s*[eE]%s*', 'e')
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 default or 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 (prefix or '') .. sign .. intPart .. fracPart .. (suffix or '')
end
function p.convert(frame)
-- Allow for invocation via #invoke or directly from another module
local args
if frame == mw.getCurrentFrame() then
args = frame.args
else
args = frame
end
local n = args.n
local base = args.base
local from = args.from
local precision = args.precision
local width = args.width
local default = args.default
local prefix = args.prefix
local suffix = args.suffix
return _convert(n, base, from, precision, width, default, prefix, suffix)
end
return p
