o1-labs / integers_stubs_js Goto Github PK

The native version of Unsigned.UInt32.to_int64 returns an int64 holding the exact same value as the given uint32, which I suppose is the expected behavior. The js stubs version, when the leftmost bit is 1, yields a different, very large number instead. I suspect the stubs are filling the 32 leftmost bits with ones instead zeroes.

let ui32 = Unsigned.UInt32.of_int 3748276426 in
let i64 = Unsigned.UInt32.to_int64 ui32 in
Format.eprintf "%Ld@." i64

Native output: 3748276426
Javascript output: 281478724987082

Saved me lot of time when I tried to port some code for the browser!

The way UInt64s are handled does not properly install the written comparison function.

I believe this is because uint64 values are actually represented as int64 so the setting of custom functions here does nothing:

    caml_custom_ops["integers:uint64"] =
    { serialize: caml_int64_marshal
    , deserialize: caml_int64_unmarshal
    , hash: caml_int64_hash
    , compare: integers_uint64_compare };

As a result, the compare function for uint64s is the signed compare, and thus does not work correctly.