swift_ids

Convert numeric IDs to human and web friendly string and back.

integer	swift_id
0	GX08
1	HY9U
2	JA2Q
5	D9YU
1000	SF7B
10000000	GM1Y3Q

features of generated id

• easy to write down / spell over the phone because generated string uses:
  • only uppercase letters,
  • no confusing digits: O=0 and I=L=1
  • no two consecutive characters are the same
• fast to convert back and forth (algorithm uses mostly binary operations)
• seems random (user can't browse trough entities easily or tell how many entities there are)
• generated id is shorter than original int as decimal (5 characters can save 8388608 ids)
• free from accidental profanities (and words in general)
• minimum length and initial zero code is configurable

usage

var encode = new Id(5);
print("${encode.value} == ${encode.toString()}"); //5 == D9YU
var decode = new Id.fromString('D9YU');
print("${decode.value} == ${decode.toString()}"); //4 == C84X

var encode2 = new Id(5, minLength:10, zero:0x55555555555);
print("${encode2.value} == ${encode2.toString()}"); //5 == HBQ8H7E85B
//same zero/minLength need to be used when decoding
var decode2 = new Id.fromString('HBQ8H7E85B', minLength:10, zero:0x55555555555);
print("${decode2.value} == ${decode2.toString()}"); //4 == C84X

//you can also create single converter instance to encode ints and decode Strings:
var converter = new IdConverter(minLength: 9, zero: 0x1234512345);
converter.decode('5S4YD9X01'); //101
converter.encode(101); //'5S4YD9X01'

zero is an initial value that is XORed with input that can be used to:

• make separate entities ids not overlap (so user with id=5 won't have same hash as message with id=5)
• mangle initial integer to prevent repetitions for small integers with large minLength
• zero should have maximum (5 * minLength) - (2 * (minLength / 3)) bits.