expectations.rs

fn main() {
	it("works", ||{
		expect("hello").to(eq("hello"));
		expect("hello").to(eq("Hello"));
		expect(1).to(eq(2));
		expect(1).to(eq(1));
	});
}

struct Expectation<T> {
    actual: T
}

impl<T: Eq + std::fmt::Show> Expectation<T> {
	fn to(&self, expected: EqMatcher<T>) {
		let success = expected.test(&self.actual);
		if !success {
			println!("Error: expected {} to equal {}", self.actual, expected.expected);
		}
	}
}

trait Matcher<T: Eq + std::fmt::Show> {
	fn test(&self, actual: &T) -> bool;
}

struct EqMatcher<T> {
	expected: T
}

fn eq<T>(expected: T) -> EqMatcher<T> {
	EqMatcher { expected: expected }
}

impl<T: Eq + std::fmt::Show> Matcher<T> for EqMatcher<T> {
	fn test(&self, actual: &T) -> bool {
		self.expected == *actual
	}
}

fn expect<T>(actual: T) -> Expectation<T> {
	Expectation { actual: actual }
}

fn it(description: &str, body: ||) {
	let _ = description;
	body();
}