errors-and-types.md

Errors and Shared Types

Silkworm uses a small set of error variants and shared type aliases to keep spider code lightweight and ergonomic.

Errors

SilkwormError provides error categories for HTTP, selectors, spider logic, pipeline handling, configuration, and IO.

Code:

• Error types: ../src/errors.rs

pub enum SilkwormError {
    Http(String),
    Selector(String),
    Spider(String),
    Pipeline(String),
    Config(String),
    Io(std::io::Error),
}

Shared Types

Type aliases simplify signatures throughout the API:

• Headers: HashMap<String, String>
• Params: HashMap<String, String>
• Meta: HashMap<String, serde_json::Value>
• Item: serde_json::Value

Conversion helpers:

• item_from: serialize a typed struct into Item.
• item_into: deserialize an Item back into a typed struct.

Code:

• Type aliases and helpers: ../src/types.rs

use serde::{Deserialize, Serialize};
use silkworm::{item_from, item_into, Item};

#[derive(Serialize, Deserialize)]
struct User {
    id: u64,
    name: String,
}

let item: Item = item_from(User { id: 1, name: "Ada".to_string() })?;
let user: User = item_into(item)?;