Support Sets with Decimal Place Component Quantities

[felix2feng]

Motivation:

We need to provide more flexibility in the token quantities that can be instantiated as they currently can only be done in whole quantities. For example, we are currently able to instantiate a Set with 1x Token A and 2x Token B with whole numbers:

Deploy with the following parameters([`address_token_a`, `address_token_b`],[1, 2], 'AB_Set`, `AB`)

If the price of Token A and Token B are sufficiently different, it will require large units of Token A and Token B to achieve certain percentage splits at a clean price. In the case that Token A is $100 and Token B is $1 and we want to achieve a 50/50 split, we'd need to have 1x Token A and 100x Token B. This results in a total Set price of $200. If a user wanted to purchase $1 of a Set, they'd need to purchase 0.005 of this Set, a figure that is psychologically unappealing.

If we wanted to represent the Set at a price of $1, we need to support decimal place representations in quantities with Set instantiation. In the same example, if we wanted to represent AB_Set with the same mix and have an initial price of $1, we can instantiate the Set with 0.05 Token A when Token A is $100 and 0.5 Token B that is $1.

Solution

In solidity, the standard ERC20 token supports up to 18 decimal places. We can support the same number in a Set.

Note: We do need to be mindful of the individual components and their decimal place limitations. For example, TRON is a ERC20 token that only supports 6 decimal places.