FRC-0046 First draft of fungible token standard.

[anorth]

This is the first draft of a fungible token standard API for native actors, as discussed in #407

An implementation of this standard is in development at https://github.com/helix-onchain/filecoin/tree/main/fil_fungible_token

FYI @jsuresh, @alexytsu @ZenGround0

[Kubuxu]

I see that decimals() was discarded. Should we provide something like granularity() from EIP-777. While rejecting transactions internally is the correct thing to do, I can see a need for knowing what is the granularity of a given token. For example a generic wallet application and users wanting to transfer half of their tokens.

[jsuresh]

@Kubuxu - I understood the purpose of granularity differently. Love a few more examples from you as I may have missed important use cases.

my understanding is everything has 18 DP as this being different is an endless source of client bugs. However, in certain use cases it doesn’t make sense to hold or transact partial tokens.

my goto example is games. Eg. Rupees in Zelda have to be ‘whole’ for use in game and therefore trading.

My assumption was in filecoin this kind of use case would be rare. However, would love to hear other motivations/examples of ways you think this would come in handy.

[anorth]

Let's take granularity discussion to #407 (comment) and leave this review for FRC style/completeness.

[jennijuju]

hi - this is our FRC-0046

[anorth]

I have pushed a new commit which:

• adds granularity method
• expands the return values from some methods
• adds tokenData separate from operatorData for the receiver hook
• clarifies a few things

[jennijuju]

is this ready for review? for fip editor?

[anorth]

@jennijuju I think it is, but I think there's one more round of minor tweaks coming, so let's wait just a week more.

[anorth]

I have pushed updates to

• make the receiver hook universal
• use FRC-42 compliant method names

Let's leave this for a day or two, but then I think it's ready for merge. Of course it's still in draft.