zig/doc/style.md

Official Style Guide

These 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 abilty 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 struct (or an alias of a struct), then x should be TitleCase.
• If x otherwise identifies a type, x should have 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.

Examples:

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

struct StructName {}
const StructAlias = StructName;

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

fn ListTemplateFunction(ChildType: type, inline fixed_size: usize) -> type {
    struct ShortList(T: type, n: usize) {
        field_name: [n]T,
        fn methodName() {}
    }
    return List(ChildType, fixed_size);
}

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

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

See Zig standard library for examples.