The release of TopoSort, a new Zig library for topological sorting of dependency graphs, has sparked discussions among developers about its practical applications and Zig's growing ecosystem. The library offers an efficient solution for managing complex dependencies, with benchmarks showing impressive performance for large datasets.
Practical Applications Beyond Academic Exercise
While topological sorting might seem like a basic computer science concept, community members have highlighted several practical applications for TopoSort. One developer mentioned using similar functionality for bringing up and shutting down OS services over two decades ago, while another suggested implementing it in an OpenCV node editor to avoid recomputing nodes multiple times. The library's ability to detect cycles and generate dependence-free subsets for parallel processing makes it particularly valuable for real-world applications.
I implemented topological sort for bringing up and shutting down OS services in order like 20 years ago, but it was like a quick and dirty way doing it and never formally as a published library.
Performance Benchmarks Show Impressive Results
TopoSort's creator shared benchmark results showing the library can process one million dependency pairs in tens of milliseconds on a five-year-old laptop. In tests with max_range optimization enabled, the library achieved impressive throughput of nearly 40 million items per second when adding dependencies. This performance makes it suitable for large-scale applications where dependency management is critical.
TopoSort Key Features
- Building dependency graphs from dependency data
- Performing topological sort on dependency graphs
- Generating dependence-free subsets for parallel processing
- Cycle detection and reporting
- Support for different node types
Benchmark Results
- 1,000,000 items (1-to-1 chaining):
- Add dependency: 93ms (10,645,885 items/s)
- Sort: 113ms (8,795,778 items/s)
- 1,000,000 items (1-to-10 chaining) with max_range optimization:
- Add dependency: 25ms (39,460,028 items/s)
- Sort: 31ms (31,633,556 items/s)
Parallel Processing Capabilities
A notable feature of TopoSort is its ability to generate dependence-free subsets for parallel processing. This functionality identifies nodes that can be processed simultaneously without dependencies on each other, potentially improving performance in multi-threaded applications. When questioned about the implementation details, the developer explained that the algorithm collects all nodes with zero in-degree (not depending on any other nodes) as a dependence-free subset at each round of processing.
Learning Tool for Zig Developers
Several commenters appreciated TopoSort not just for its functionality but as an exemplary project for those learning Zig. The project demonstrates proper package structure, CLI tool implementation, and library design in Zig. The developer mentioned that creating a fully-featured library with proper error handling and user-friendly interfaces required significantly more code than the core algorithm (about 20 lines), highlighting the difference between an idea and a product.
Zig Language Discussions
The TopoSort announcement also triggered broader discussions about Zig as a programming language. Some developers expressed enthusiasm for Zig's capabilities while noting limitations, particularly around compile-time features. One developer mentioned they find Zig preferable to C/C++ in many cases but are waiting for certain compile-time features before committing to larger projects. Others debated syntax choices, with some finding Zig's array syntax unintuitive compared to languages like Rust.
In conclusion, TopoSort represents both a useful tool for dependency management and a quality example of Zig library development. The community's response indicates growing interest in Zig's ecosystem and practical applications of computer science fundamentals in modern software development.