[Feature] support simplify Provider type

[sunliang711]

Component

provider, pubsub

Describe the feature you would like

I want to create a function to return Provider type,but I must use type alias to define a looong provider type:

type Provider = alloy::providers::fillers::FillProvider<
    alloy::providers::fillers::JoinFill<
        alloy::providers::fillers::JoinFill<
            alloy::providers::Identity,
            alloy::providers::fillers::JoinFill<
                alloy::providers::fillers::GasFiller,
                alloy::providers::fillers::JoinFill<
                    alloy::providers::fillers::BlobGasFiller,
                    alloy::providers::fillers::JoinFill<
                        alloy::providers::fillers::NonceFiller,
                        alloy::providers::fillers::ChainIdFiller,
                    >,
                >,
            >,
        >,
        alloy::providers::fillers::WalletFiller<EthereumWallet>,
    >,
    alloy::providers::RootProvider<alloy::transports::http::Http<alloy::transports::http::Client>>,
    alloy::transports::http::Http<alloy::transports::http::Client>,
    alloy::network::Ethereum,
>;
pub fn provider_with(rpc_url: &str, wallet: EthereumWallet) -> Result<Provider> {
    let url = Url::parse(rpc_url)?;
    let provider_builder = ProviderBuilder::new().with_recommended_fillers();
    let provider = provider_builder.wallet(wallet).on_http(url);

    Ok(provider)
}

how do i simplify this code ? thanks in advance .

Additional context

No response

[scaraven]

I struggled with this for a while as well, simply because I am relatively new to rust.

Assuming that you are happy with being constrained to an HTTP Provider, I would use either:

pub fn provider_with(rpc_url: &str, wallet: EthereumWallet) -> Result<impl Provider<Http<Client>>> {}

or

pub fn provider_with(rpc_url: &str, wallet: EthereumWallet) -> Result<Box<dyn Provider<Http<Client>>>> {}

depending on whether you only care about using this specific provider but want to hide the return type from any callers (impl) or you potentially want to work with lots of different providers (dyn).

Additionally, if you want to abstract even further, then it might be worth using on_builtin() rather than on_http() but that opens another can of worms.