cdumay_context

A flexible context management library that provides a trait-based approach for handling key-value data with support for multiple serialization formats.

Features

• Generic context management through the Context trait
• Support for multiple serialization formats (with feature flags):
  • JSON (feature: "json")
  • TOML (feature: "toml")
  • YAML (feature: "yaml")
• Type-safe error handling with the Error enum

Example Usage

use std::collections::BTreeMap;
use serde::{Serialize, Deserialize};
use cdumay_context::{Context, Error};

#[derive(Default, Serialize, Deserialize)]
struct MyContext {
    data: BTreeMap<String, serde_value::Value>
}

impl Context for MyContext {
    fn new() -> Self {
        Self::default()
    }

    fn insert(&mut self, k: String, v: serde_value::Value) {
        self.data.insert(k, v);
    }

    fn get(&self, k: &str) -> Option<&serde_value::Value> {
        self.data.get(k)
    }

    fn extend(&mut self, data: BTreeMap<String, serde_value::Value>) {
        self.data.extend(data);
    }

    fn inner(&self) -> BTreeMap<String, serde_value::Value> {
        self.data.clone()
    }
}

// Basic usage
let mut ctx = MyContext::new();
ctx.insert("name".to_string(), serde_value::Value::String("Alice".to_string()));

// JSON serialization (requires "json" feature)
#[cfg(feature = "json")]
{
    let json = ctx.to_json(true).unwrap();
    let ctx_from_json = MyContext::from_json(&json).unwrap();
    assert_eq!(ctx.get("name"), ctx_from_json.get("name"));
}

// TOML serialization (requires "toml" feature)
#[cfg(feature = "toml")]
{
    let toml = ctx.to_toml(true).unwrap();
    let ctx_from_toml = MyContext::from_toml(&toml).unwrap();
    assert_eq!(ctx.get("name"), ctx_from_toml.get("name"));
}

Error Handling

The library provides a comprehensive error handling system through the Error enum:

use std::collections::BTreeMap;
use serde::{Serialize, Deserialize};
use cdumay_context::{Context, Error};
use rand::Rng;

#[derive(Default, Serialize, Deserialize)]
struct MyContext {
    data: BTreeMap<String, serde_value::Value>
}

impl Context for MyContext {
    fn new() -> Self {
        Self::default()
    }

    fn insert(&mut self, k: String, v: serde_value::Value) {
        self.data.insert(k, v);
    }

    fn get(&self, k: &str) -> Option<&serde_value::Value> {
        self.data.get(k)
    }

    fn extend(&mut self, data: BTreeMap<String, serde_value::Value>) {
        self.data.extend(data);
    }

    fn inner(&self) -> BTreeMap<String, serde_value::Value> {
        self.data.clone()
    }
}

fn example_error_handling() -> Result<(), Error> {
    let mut rng = rand::thread_rng();
    let dice_roll: u8 = rng.gen_range(1..=6);

    // Generic error
    if dice_roll == 7 {
        return Err(Error::Generic("Something went wrong".to_string()));
    }

    // JSON error (with "json" feature)
    #[cfg(feature = "json")]
    {
        let invalid_json = "{ invalid: json }";
        let result = MyContext::from_json(invalid_json);
        assert!(matches!(result, Err(Error::Json(_))));
    }
    Ok(())
}