Use string for name and symbol

[brianmcmichael]

Recent versions of solc do not treat bytes32 and string in the same way that it used to, they are no longer comparable or directly castable. Therefore, creating token integrations with more recent versions of solc have difficulty processing the DS-Token's bytes32 return from name and string. The ERC20 standard does call for string types to be used for these optional returns so I'm just putting this forth as a suggestion.

[d-xo]

Is there some nice way to have these strings be constant? dynamic types and memory parameters are quite annoying for FV.

[brianmcmichael]

@xwvvvvwx that gets into a philosophical discussion. In ds-token now, they symbol is set via the constructor and the name is set via a setter function. To be constant you'd have to hard-code them into the contract prior to deployment and you wouldn't be able to pass them as params. I don't want to change those patterns without the blessing of the maintainers. solc 0.6.5+ allows for immutable variables to be set via a constructor, but I'm not sure if that would achieve any benefit by way of formal verification, and the existing ds-token isn't 0.6.x compatible anyways.

[gbalabasquer]

Unfortunately immutable doesn't work with string type.

[d-xo]

@brianmcmichael If you rebase this onto latest master I will merge

[brianmcmichael]

Rebased.

[d-xo]

oops, looks like merging the decimals PR created a conflict here, can you rebase again.

[brianmcmichael]

Rebased again.