| name | zig-best-practices |
| description | Use when reading or writing Zig files (.zig, build.zig, build.zig.zon). |
Zig Best Practices
Follows type-first, functional, and error handling patterns from CLAUDE.md. This skill covers Zig-specific idioms only.
Type System Patterns
Tagged unions for mutually exclusive states — prevents invalid combinations that a struct with multiple nullable fields would allow:
const RequestState = union(enum) {
idle,
loading,
success: []const u8,
failure: anyerror,
};
Explicit error sets — documents exactly what can fail; anyerror hides failure modes:
const ParseError = error{ InvalidSyntax, UnexpectedToken, EndOfInput };
fn parse(input: []const u8) ParseError!Ast { ... }
Distinct types for domain IDs — compiler prevents mixing up different ID types:
const UserId = enum(u64) { _ };
const OrderId = enum(u64) { _ };
Comptime validation — catch invalid configurations at compile time, not runtime:
fn Buffer(comptime size: usize) type {
if (size == 0) @compileError("buffer size must be greater than 0");
return struct { data: [size]u8 = undefined, len: usize = 0 };
}
Memory Management
- Pass allocators explicitly to every function that allocates; no global allocator state.
- Place
defer resource.deinit() immediately after acquisition — keeps cleanup co-located with creation.
- Use
errdefer for cleanup on error paths; defer for unconditional cleanup.
- Use arena allocators for batch/temporary work; they free everything at once.
- Use
std.testing.allocator in tests — reports leaks with stack traces.
fn createResource(allocator: std.mem.Allocator) !*Resource {
const resource = try allocator.create(Resource);
errdefer allocator.destroy(resource); // runs only on error
resource.* = try initializeResource();
return resource;
}
Key Conventions
- Prefer
const over var; prefer slices over raw pointers.
- Prefer
comptime T: type over anytype; explicit types produce clearer errors. Use anytype only for genuinely polymorphic cases (callbacks, std.debug.print-style).
- Exhaustive
switch: include an else returning an error or unreachable for truly impossible cases.
- Use
std.log.scoped(.module_name) for namespaced logging; define a module-level const log constant.
- Larger cohesive files are idiomatic — tests alongside implementation, comptime generics at file scope.
Advanced Topics
- Generic containers (queues, stacks, trees): See GENERICS.md
- C library interop (raylib, SDL, curl): See C-INTEROP.md
- Debugging memory leaks (GPA, stack traces): See DEBUGGING.md
Tooling
zigdoc — browse std library and dependency docs:
zigdoc std.mem.Allocator
zigdoc vaxis.Window
zigdoc @init
ziglint — static analysis with .ziglint.zon config:
ziglint
ziglint --ignore Z001
References