Messages and queries can be sent from smart contracts in the EVM. This is by an opt-in basis, so you’ll need to use the EVM message/query constructors when instantiating your messages and queries to enable EVM support.

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Supported Types

Below are the Go types available to use in struct fields when utilizing using EVM supported messages and queries.

  • []byte (resolves to bytes in ABI encoding)
  • string
  • bool
  • int8 - int64
  • uint8 - uint64
  • github.com/ethereum/go-ethereum/common.Address (resolves to address in ABI encoding)
  • *math/big.Int (resolves to a specified int or uint above 64 bits i.e. uint128)

Additionally, slices of all the above types work as well.

When using *big.Int, you MUST use a special “evm” struct tag to indicate which underlying evm integer type you want to resolve to. This is due to go-ethereum using *big.Int for any uint or int greater than 64 bits.

Example:

type Foo struct {
    Num *big.Int `evm:"uint256"`
}