Style Guide

Style Guide

These coding conventions are not enforced by the compiler, but they are shipped in this documentation along with the compiler in order to provide a point of reference, should anyone wish to point to an authority on agreed upon Zig coding style.

Whitespace

• 4 space indentation
• Open braces on same line, unless you need to wrap.
• If a list of things is longer than 2, put each item on its own line and exercise the ability to put an extra comma at the end.
• Line length: aim for 100; use common sense.

Names

Roughly speaking: camelCaseFunctionName, TitleCaseTypeName, snake_case_variable_name. More precisely:

• If x is a type then x should be TitleCase, unless it is a struct with 0 fields and is never meant to be instantiated, in which case it is considered to be a "namespace" and uses snake_case.
• If x is callable, and x's return type is type, then x should be TitleCase.
• If x is otherwise callable, then x should be camelCase.
• Otherwise, x should be snake_case.

Acronyms, initialisms, proper nouns, or any other word that has capitalization rules in written English are subject to naming conventions just like any other word. Even acronyms that are only 2 letters long are subject to these conventions.

These are general rules of thumb; if it makes sense to do something different, do what makes sense. For example, if there is an established convention such as ENOENT, follow the established convention.

Examples

const namespace_name = @import("dir_name/file_name.zig");
var global_var: i32 = undefined;
const const_name = 42;
const primitive_type_alias = f32;
const string_alias = []u8;

const StructName = struct {
    field: i32,
};
const StructAlias = StructName;

fn functionName(param_name: TypeName) void {
    var functionPointer = functionName;
    functionPointer();
    functionPointer = otherFunction;
    functionPointer();
}
const functionAlias = functionName;

fn ListTemplateFunction(comptime ChildType: type, comptime fixed_size: usize) type {
    return List(ChildType, fixed_size);
}

fn ShortList(comptime T: type, comptime n: usize) type {
    return struct {
        field_name: [n]T,
        fn methodName() void {}
    };
}

// The word XML loses its casing when used in Zig identifiers.
const xml_document =
    \\<?xml version="1.0" encoding="UTF-8"?>
    \\<document>
    \\</document>
;
const XmlParser = struct {
    field: i32,
};

// The initials BE (Big Endian) are just another word in Zig identifier names.
fn readU32Be() u32 {}

See the Zig Standard Library for more examples.