use std/io.print func greet(user: User): void! { let name = user.display.name() otherwise { "guest" } let tone = match user.presence { Presence.online { "hello" } Presence.away { "welcome back" } } print("${tone}, ${name}\n")? }

interface Writer { pub method &+self.write(bytes: &[u8]): void! } func save_log(output: &+Writer, events: &[Event]): void! { for event in events { output.write(event.message().bytes())? output.write("\n".bytes())? } }

pub struct Session { id: SessionId user: User expires_at: Time } pub func Session.start(user: User, clock: &Clock): Session { return Session { id: SessionId.new(), user: move user, expires_at: clock.now().plus_minutes(30), } }

construct NonEmptyList<T> { pub default literal [](...items: T): Self from items { var list = Self.new() for item in items { list.push(move item) } return move list } }

error.nct

//! Common error classification API.
//!
//! `error` is the compiler built-in fallible payload type. Error and ErrorCode
//! are ordinary standard-library names that user modules receive through the
//! synthetic prelude.
//!
//! ErrorCode is intentionally open. Standard-library and user-library code use
//! dotted string codes such as "std.io.not_found" or "app.config.missing_key".

pub type ErrorCode = &str
pub type Error = error

pub(nocter) primitive new_error(code: &str, message: &str): error

pub func Error.new(code: ErrorCode, message: &str): Error from code | message {
    return new_error(code, message)
}