Floating Point Numbers in Offchain Workers

[apopiak]

Because we don't rely on determinism in offchain workers we could support floating point numbers in principle.
What are the obstacles for enabling this?

[kianenigma]

I am bit unsure what we would even have to do to support float? I thought that it is always there, we just discourage it.

[xlc]

How do you ensure the float included code will not get called by on-chain logic?

We are using fixed point number and it is doing fine for us.

[jak-pan]

This probably spun out of my question.

The reason I asked this initially was that we wanted to get a price from an oracle included in the blockchain which is deserialized as float and method from_fraction() of Fixed numbers is hidden behind std flag. We all understand that we shouldn't use floats in runtime but it seemed like these convenience functions should be available.

@apopiak however pointed other way to do this easily by using lite-json so it might be non-issue.

The question IMO is still interesting though. As long as you pass correct data to the runtime, why should ocw logic be constrained like runtime is?

[gui1117]

The question IMO is still interesting though. As long as you pass correct data to the runtime, why should ocw logic be constrained like runtime is?

I think feature gating float usage with flag "std" allowed us not to use float accidentally in the runtime. As far as I know float are supported in the runtime and you can use them.

Maybe we could introduce a new feature "ocw" and always ensure the runtime (without offchain worker) compiles without "ocw" feature and pass test suite. But this doesn't completely prevent us from using "ocw" feature accidentally in the runtime.