Swiflet provides => which works like let in Kotlin. => is useful when a return value is used multiple times in an expression.
// Similar to `x() * x()` but calls `x()` just once
let square = x() => { $0 * $0 }It is possible to throw errors in a closure passed to => because => is marked with rethrows.
do {
try x() => { try throwable($0, $0) }
} catch {
// Error handling
}MIT