Crate r_resources 

r-resources

Android-style resource management for Rust with compile-time type safety.

This library provides a build-time resource management system inspired by Android’s R class. Resources are defined in an XML file and compiled into type-safe Rust constants at build time, resulting in zero runtime overhead.

Quick Start

1. Create a res/values.xml file in your project root:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">My Application</string>
    <int name="max_retries">3</int>
    <float name="version">1.0</float>
</resources>

2. Include resources in your code:

use r_resources::include_resources;
include_resources!();
use r_resources::*;
// Option 1: Type-organized access
let _ = string::APP_NAME;
let _ = int::MAX_RETRIES;
let _ = float::VERSION;
// Option 2: Flat access via r module
let _ = r::APP_NAME;
let _ = r::MAX_RETRIES;
let _ = r::VERSION;

Supported Resource Types

• Strings: <string name="key">value</string> → string::KEY or r::KEY
• Integers: <int name="key">42</int> → int::KEY or r::KEY
• Floats: <float name="key">3.14</float> → float::KEY or r::KEY
• String Arrays: <string-array name="key">...</string-array> → string_array::KEY or r::KEY
• Integer Arrays: <int-array name="key">...</int-array> → int_array::KEY or r::KEY
• Float Arrays: <float-array name="key">...</float-array> → float_array::KEY or r::KEY

Both access methods are available:

• Type-organized: string::APP_NAME (clearer, avoids naming conflicts)
• Flat access: r::APP_NAME (shorter, more convenient)

Features

• Build-time compilation: All resources are compiled into your binary
• Type-safe: Each resource type has its own module
• Zero runtime cost: Direct constant access, no parsing or lookups
• Thread-safe: All resources are const and can be safely accessed from any thread
• Async-safe: Works seamlessly in async contexts (tokio, async-std, etc.)
• Familiar syntax: Inspired by Android’s resource system

Thread Safety

All generated resources are const values, making them inherently thread-safe:

use std::thread;
use r_resources::*;

let handles: Vec<_> = (0..10)
    .map(|_| {
        thread::spawn(|| {
            // Safe to access from multiple threads
            println!("{}", string::APP_NAME);
        })
    })
    .collect();

for handle in handles {
    handle.join().unwrap();
}

Macros

include_resources

Includes the generated resources from the build script.

Structs

Color

Typed color parsed from hex (e.g., #RRGGBB or #AARRGGBB).

LatLng

Geographic coordinates.

Position

2D position.

UrlParts

Typed URL parts split at build-time.

Functions

build

Runs the code generation. Intended to be called from a consumer’s build.rs.