==================
Top-level functions
==================

fun main() {}

---

(source_file
	(function_declaration
		(simple_identifier)
		(function_body)))

==================
Generic functions
==================

<T> fun test() {}

---

(source_file
	(function_declaration
		(type_parameters (type_parameter (type_identifier)))
		(simple_identifier)
		(function_body)))

==================
Functions with parameters
==================

fun main(args: Array<String>) {}

fun sum(a: Int, b: Int) = a + b

---

(source_file
	(function_declaration
		(simple_identifier)
		(parameter 
			(simple_identifier)
			(user_type
				(type_identifier)
				(type_arguments (type_projection (user_type (type_identifier))))))
		(function_body))
	(function_declaration
		(simple_identifier)
		(parameter
			(simple_identifier)
			(user_type (type_identifier)))
		(parameter
			(simple_identifier)
			(user_type (type_identifier)))
		(function_body
			(additive_expression
				(simple_identifier)
				(simple_identifier)))))

==================
Functions with return types
==================

fun answerToTheUltimateQuestionOfLifeTheUniverseAndEverything(): Int = 42

---

(source_file
	(function_declaration
		(simple_identifier)
		(user_type (type_identifier))
		(function_body (integer_literal))))