Appendix B: Operators and Symbols

This appendix provides a quick reference for all operators in Oxide, including their precedence and Oxide-specific operators.

Operator Precedence Table

Operators are listed from highest precedence (evaluated first) to lowest (evaluated last).

Operators by Category

Arithmetic Operators

Comparison Operators

Logical Operators

Bitwise Operators

Reference Operators

Assignment Operators

Range Operators

Oxide-Specific Operators

Null Coalescing (??)

Provides a default value when the left-hand side is null.

let name = userName ?? "Anonymous"
let config = Config.load() ?? Config.default()

CRITICAL: ?? works with Option<T> ONLY, NOT Result<T, E>

// This will NOT compile:
let value: Result<Int, Error> = Err(someError)
let result = value ?? 0  // ERROR: ?? only works with Option<T>

Why? Result<T, E> contains typed error information that should not be silently discarded. Using ?? would hide important error details.

For Result, use explicit methods:

let value = riskyOperation().unwrapOr(default)
let value = riskyOperation().unwrapOrElse { err -> handleError(err) }

Rust equivalent: .unwrap_or() or .unwrap_or_else()

Force Unwrap (!!)

Forcefully unwraps an optional value. Panics if null.

let user = findUser(id)!!  // Panics if null

Rust equivalent: .unwrap()

Warning: Use sparingly. Prefer if let, pattern matching, or ?? when possible.

Prefix Await

Oxide uses prefix await (unlike Rust's postfix .await).

let data = await fetchData()
let response = await client.get(url).send()?

Precedence: await binds tighter than ?, so await expr? means (await expr)?

Rust equivalent: expr.await

Try Operator (?)

Unchanged from Rust. Propagates errors in Result or Option returning functions.

fn readConfig(): Result<Config, Error> {
    let content = std.fs.readToString("config.toml")?
    Ok(parseConfig(content)?)
}

Symbols and Delimiters

Summary: Differences from Rust

IMPORTANT: The Rust operators in the right column (::, -> for return types, => for match arms) are not valid Oxide syntax. These are grammar changes, not style preferences. Using :: in Oxide code will result in a syntax error. Oxide uses . as its only path separator.