luhn-generator
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A generator of numbers that passes the validation of Luhn algorithm or Luhn formula, also known as the 'modulus 10' or 'mod 10' algorithm
47 lines (42 loc) • 1.31 kB
JavaScript
var arrayEach = require('./_arrayEach'),
arrayIncludes = require('./_arrayIncludes');
/** Used to compose bitmasks for function metadata. */
var WRAP_BIND_FLAG = 1,
WRAP_BIND_KEY_FLAG = 2,
WRAP_CURRY_FLAG = 8,
WRAP_CURRY_RIGHT_FLAG = 16,
WRAP_PARTIAL_FLAG = 32,
WRAP_PARTIAL_RIGHT_FLAG = 64,
WRAP_ARY_FLAG = 128,
WRAP_REARG_FLAG = 256,
WRAP_FLIP_FLAG = 512;
/** Used to associate wrap methods with their bit flags. */
var wrapFlags = [
['ary', WRAP_ARY_FLAG],
['bind', WRAP_BIND_FLAG],
['bindKey', WRAP_BIND_KEY_FLAG],
['curry', WRAP_CURRY_FLAG],
['curryRight', WRAP_CURRY_RIGHT_FLAG],
['flip', WRAP_FLIP_FLAG],
['partial', WRAP_PARTIAL_FLAG],
['partialRight', WRAP_PARTIAL_RIGHT_FLAG],
['rearg', WRAP_REARG_FLAG]
];
/**
* Updates wrapper `details` based on `bitmask` flags.
*
* @private
* @returns {Array} details The details to modify.
* @param {number} bitmask The bitmask flags. See `createWrap` for more details.
* @returns {Array} Returns `details`.
*/
function updateWrapDetails(details, bitmask) {
arrayEach(wrapFlags, function(pair) {
var value = '_.' + pair[0];
if ((bitmask & pair[1]) && !arrayIncludes(details, value)) {
details.push(value);
}
});
return details.sort();
}
module.exports = updateWrapDetails;