Is it possible to work with big numbers like 256 bit unsigned integers in Motoko?

Developers
1

Hello Dears!

Is it possible to work with big numbers like 256 bit unsigned integers in Motoko?

2

Nat will represent numbers that large, but it’s not specific to a certain bit width.

When you say “working with”, what operations do you need?

Nat is described here (partly): Nat :: Internet Computer

3

I mean multiplication of two numbers like this one 123456789123456789 * 123456789123456789
when I did this then it produces “lost precision” error

4

Strange. I just tried the same multiplication in the Motoko repl and got this (no error):

Motoko compiler 0.6.5 (source ac3psafn-rp9bj68x-67s21qfv-z7fygv81)
> 123456789123456789 * 123456789123456789
  ;;
15_241_578_780_673_678_515_622_620_750_190_521 : Nat
>

You get that error from the Motoko compiler, during compile time?

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5

Oh sorry, it works for me also. But the actual problem is causes from conversion more than 64bit number to Float. Now actual question is: Is there any way to get square root of numbers bigger than 64 bits?
Here the code:

var num = 112345678912345678900 * 112345678912345678900; // OK
var ftval = Float.fromInt(num); // <- error
var sqr = Float.sqrt(ftval);

canister trapped explicitly: losing precision

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6

I opened new topic for this question

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7

Oh, hey if youre still here, I think Floating point numbers only have like x number of decimal precisioin for any language. If you want to use super big numbers you have to use massive ints but consider the last x number as “decimal” digits

1 Like