🎯 CAND - Colorful And Nice Debugging

Beautiful embedded-first Rust logging library for ESP32 to servers with colorful output and zero-panic design.

✨ Why Choose CAND?

Feature	Benefit	Use Case
🎨 Smart Colors	Spot issues instantly	`logger.log_err("❌ Clear visibility")`
⚡ no_std Ready	Runs everywhere	ESP32, STM32, WASM, bare metal
🛡️ Never Panic	Production safe	`try_run()` handles all errors gracefully
🔌 Pluggable	Your infrastructure	Files, UART, RTT, databases, networks
📦 Tiny Binary	<1KB overhead	Perfect for memory-constrained devices
🎯 2-Line Setup	Start in seconds	Works out of the box

🚀 Quick Start

Desktop/Server

[dependencies]
cand = "0.1"

use cand::Logger;
use std::time::Instant;

fn main() {
  let mut logger = Logger(Instant::now(), ());
    
  logger.log_ok("🚀 Server started successfully!");
  logger.log_info("📡 Listening on port 8080");
  logger.log_warn("⚠️ High memory usage: 87%");
  logger.log_err("❌ Database connection failed");
}

Embedded/ESP32 with no_std

[dependencies]
cand = { version = "0.1", default-feature=false, features=["colors"] }

🎨 Beautiful Output

CAND automatically color-codes your logs for instant visual feedback:

🟢 log_ok() - Success operations (green)
🔵 log_info() - Informational messages (blue)
🟡 log_warn() - Warnings that need attention (yellow)
🔴 log_err() - Critical errors (red)

sample of output

🛡️ Error Handling That Never Panics

use cand::Logger;

fn risky_operation() -> Result<String, &'static str> {
  Err("network timeout")
}

fn fallback_handler(mut logger: Logger<std::time::Instant, ()>) {
  logger.log_warn("🔄 Entering fallback mode");
  logger.log_info("💾 Switching to cached data");
}

fn main() {
  let logger = Logger(std::time::Instant::now(), ());
    
  // Automatic error logging and graceful recovery
  let (data, recovered_logger) = logger.try_run(
    risky_operation(),
    fallback_handler
  );
}

Embedded UART

struct UartStorage{
  // Serial can be from any mcu serial
  serial: Serial 
};

impl StorageProvider for UartStorage {
  fn write_data(&mut self, d: impl ufmt::uDebug) {
    // Write to UART, RTT, or any embedded output
    ufmt::uwrite!(self.serial,"{:?}", d);
  }
}

🎛️ Feature Flags

Feature	Description	Default
`std`	Standard library support, enables `Instant` time provider	✅
`colors`	ANSI color output for beautiful terminal logs	✅
`ufmt`	Embedded-friendly formatting with zero allocations	No

📊 Performance

⚡ Zero allocations with ufmt feature
🚀 178147+ logs/second on example benchmark

🏗️ API Reference

Core Types

// Make sure Type should TimeProvider or StorageProvider
// Main logger with time and storage providers
pub struct Logger<T: TimeProvider, S: StorageProvider>(pub T, pub S);

🧪 Examples

Check out the examples directory:

basic_error_handling - Error recovery patterns
sample - Feature showcase and demo
benchmark - Benchmark of 10_000 logs print

Run examples:

cargo run --example sample

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

cand 0.1.0