# Rust and Alloy-RS

Learning Rust and Alloy-RS

## Checksum an Address

### Before

use std::str::FromStr;

use alloy_primitives::{Address, U256};


pub fn checksum(address: &str) -> String {
    match Address::from_str(address) {
        Ok(addr) => addr.to_checksum(None),
        Err(_) => {
            tracing::error!("Invalid address: {}", address);
            address.to_string()
        }
    }
}

### After

use std::str::FromStr;

use alloy_primitives::{Address, U256};


pub fn checksum(address: &str) -> String {
    Address::from_str(address)
        .map(|addr| addr.to_checksum(None))
        .unwrap_or_else(|_| {
            tracing::error!("Invalid address: {}", address);
            address.to_string()
        })
}

### Diff

------ checksum.rs
++++++ checksum.rs
@|-1,14 +1,13 ============================================================
 |use std::str::FromStr;
 |
 |use alloy_primitives::{Address, U256};
 |
 |
 |pub fn checksum(address: &str) -> String {
-|    match Address::from_str(address) {
-|        Ok(addr) => addr.to_checksum(None),
-|        Err(_) => {
+|    Address::from_str(address)
+|        .map(|addr| addr.to_checksum(None))
+|        .unwrap_or_else(|_| {
 |            tracing::error!("Invalid address: {}", address);
 |            address.to_string()
-|        }
-|    }
+|        })
 |}

## Hash to Name

### Before

pub fn hash_to_name(hash: &str) -> String {
    if !hash.starts_with("0x0000") {
        return hash[1..6].to_lowercase();
    }

    let len = hash.len();
    let trimmed = hash.trim_start_matches("0x").trim_start_matches('0');
    let trimmed = if trimmed.len() < 4 { &hash[len - 4..] } else { trimmed };

    format!("x{}", &trimmed[..4].to_lowercase())
}

### After

pub fn hash_to_name(hash: &str) -> String {
    if !hash.starts_with("0x0000") {
        return hash[1..6].to_lowercase();
    }

    let trimmed = hash.trim_start_matches("0x").trim_start_matches('0');
    let slice = if trimmed.len() < 4 {
        &hash[hash.len().saturating_sub(4)..]
    } else {
        &trimmed[..4]
    };

    format!("x{}", slice.to_lowercase())
}