Module errors 

Error types for the semioscan library.

This module provides strongly-typed errors for all public APIs in semioscan. It follows a hybrid approach:

• Module-specific errors for fine-grained error handling (BlockWindowError, GasCalculationError, etc.)
• Unified error type (SemioscanError) for convenience when you don’t need to distinguish between error sources

Architecture

Each major module has its own error type:

• BlockWindowError - Errors from block window calculations
• GasCalculationError - Errors from gas cost calculations
• PriceCalculationError - Errors from price calculations (wraps crate::price::PriceSourceError)
• EventProcessingError - Errors from event scanning and processing
• RetrievalError - Errors from combined data retrieval operations

Additionally, RpcError provides shared error variants for blockchain RPC operations.

Examples

Fine-grained error handling

use semioscan::{BlockWindowCalculator, BlockWindowError};
use alloy_chains::NamedChain;
use chrono::NaiveDate;

async fn example() -> Result<(), Box<dyn std::error::Error>> {
    let calculator = BlockWindowCalculator::with_disk_cache(provider, "cache.json")?;
    let date = NaiveDate::from_ymd_opt(2024, 1, 15).unwrap();

    match calculator.get_daily_window(NamedChain::Arbitrum, date).await {
        Ok(window) => println!("Block window: {:?}", window),
        Err(BlockWindowError::InvalidRange { reason }) => {
            eprintln!("Invalid range: {}", reason);
        }
        Err(BlockWindowError::Rpc(rpc_err)) => {
            eprintln!("RPC failure, retrying...: {}", rpc_err);
        }
        Err(e) => eprintln!("Other error: {}", e),
    }
    Ok(())
}

Using the unified error type

use semioscan::{SemioscanError, BlockWindowCalculator};
use alloy_chains::NamedChain;
use chrono::NaiveDate;

async fn example() -> Result<(), SemioscanError> {
    let calculator = BlockWindowCalculator::with_disk_cache(provider, "cache.json")?;
    let date = NaiveDate::from_ymd_opt(2024, 1, 15).unwrap();
    let window = calculator.get_daily_window(NamedChain::Arbitrum, date).await?;
    // Errors automatically convert to SemioscanError via From implementations
    Ok(())
}

Enums

BlockWindowError

Errors that can occur during block window calculations.

EventProcessingError

Errors that can occur during event processing.

GasCalculationError

Errors that can occur during gas cost calculations.

PriceCalculationError

Errors that can occur during price calculations.

RetrievalError

Errors that can occur during data retrieval operations.

RpcError

Errors that can occur during blockchain RPC operations.

SemioscanError

Unified error type for all semioscan operations.