Lesson 12: How Close Must the Implementation be to the ERC-20 Specification?

[PCWCFA]

I noted the ERC-20 specification used in Lesson 12 calls for an allowance function, but the example ManualToken implementation does not have an allowance function. Yes, I understand the allowance is accounted for in transferFrom, but how close must ManualToken's implementation be to the specification in order for it to be considered ERC-20? Can a function be dropped and the implementation still be ERC-20?

[krakxn]

It just that we have not implemented a getter function for allowance (we indeed are using allowances to account for vector attacks though - via a mapping/hash map) which is specified in the EIP-20.

And as for "Can a function be dropped and the implementation still be ERC-20?" - I'm pretty sure it has to follow the general concept as described in the proposal for it to conform to the ERC-20 standard (if you are technical: "ERC-20 contains several functions and events that a token must implement. Keep in mind that this standard also governs actions that smart contracts take for the tokens being created. The minimum of functions and information needed in an ERC-20 compliant token are the ones listed in the EIP") Hope this answers your doubts!

[PCWCFA]

Krakxn, thanks. Based on your answer, then all functions and events that are not marked optional need to be implemented.

[krakxn]

You're welcome, and yes, you got it. I will emphasize the bold text again just for clarity: The minimum of functions and information needed in an ERC-20 compliant token are the ones listed in the EIP. Good luck with the course!