The syntax is (x, …) => …, or x => … for single-parameter lambdas. The types of the arguments may be specified by (T x) => … (here, parentheses are required for single-parameter lambdas). The result type cannot be specified.
Variables are captured by reference.
Lambdas have no implicit type (so cannot be assigned to an automatically-typed variable) but are implicitly convertible to any compatible delegate type.
The syntax is [captures](T x, …) { … }. captures is a ‘capture list’ that explicitly states what is captured in the closure, and whether it is captured by reference or by value. The return type may be explicitly specified with [](T x) -> ReturnT { … }.
The implicit type of a lambda is an unspeakable name, so in order to pass them to a function, it must be templated or take a type that hides the real type, such as std::function.
The syntax is fun x y … -> …. Like normal functions they are curried. Type annotations can be added in the usual manner fun (x : T) … -> ….
Variables are captured by reference.
The syntax is \x y … -> …. Type annotations can be added in the usual manner \(x :: T) -> ….
The syntax is (x, y) -> … or x -> … for single-parameter lambdas. Types can be supplied with (T x, …) -> …. The result type cannot be specified.
Anonymous functions are simply declared without a name: function (x, …){ … }.
Since ES6 (2015), the ‘arrow’ syntax can also be used: (x, …) => …, or x => … for single-parameter functions.
The syntax is @(x, …) ….
The syntax is lambda x, …: ….
Variables are captured by reference.