Declaration

Function names must begin with a lowercase letter.

No parameters, no return

fun say_hello()
{
    print("Hello")
}

say_hello()thp
    

With return type

fun get_random_number() -> Int
{
    Random::get(0, 35_222)
}

val number = get_random_number()thp
    
Syntax error: There should be an identifier after a binding at line 3:11

With parameters and return type

fun get_secure_random_number(Int min, Int max) -> Int
{
    Random::get_secure(min, max)
}

val number = get_secure_random_number(0, 65535)thp
    
Syntax error: There should be an identifier after a binding at line 3:11

Generic types

fun get_first_item[T](Array[T] array) -> T
{
    array[0]
}

val first = get_first_item[Int](numbers)
// The type annotation is optional if the compiler can infer the type

val first = get_first_item(numbers)thp
    
Syntax error: Expected an opening paren after the function identifier. at line 1:18

Signature

() -> ()
() -> (Int)
(Int, Int) -> (Int)
[T](Array[T]) -> (T)thp
    
Syntax error: Expected an statement or an expresion at the top level. at line 1:0

Named arguments

fun html_special_chars(
    String input,
    Int? flags,
    String? encoding,
    Bool? double_encoding,
) -> String
{
    // ...
}

html_special_chars(input, double_encoding: false)thp
    
Syntax error: Expected an identifier for the parameter. at line 3:1

TBD: If & how named arguments affect the order of the parameters

Named arguments with different names

fun greet(
    String name,
    String from: city,
)
{
    print("Hello {name} from {city}!")
}

greet("John", from: "LA")thp
    
Syntax error: Expected a closing paren after the function identifier. at line 3:16