Lambdas / Anonymous functions
Anonymous function
fun(Int x, Int y) -> Int {
x + y
}
numbers.map(fun(x) {
x * 2
})
thp
Syntax error: Expected an identifier after the `fun` keyword. at line 1:3
Closure types
By default closures always capture variables as references.
var x = 20
val f = fun() {
print(x)
}
f() // 20
x = 30
f() // 30
thp
Syntax error: Expected an expression after the equal `=` operator at line 3:7
You can force a closure to capture variables by value.
fun(parameters) clone(variables) {
// code
}
thp
Syntax error: Expected an identifier after the `fun` keyword. at line 1:3
var x = 20
val f = fun() clone(x) {
print(x)
}
f() // 20
x = 30
f() // 20
thp
Syntax error: Expected an expression after the equal `=` operator at line 3:7
Lambdas
Lambdas are a short form of anonymous functions. They are declared with #{}
.
Inside the lambda you can access the parameters as $1
, $2
, etc.
Finally, lambdas be written outside of the parenthesis of function calls.
numbers.map() #{
$1 * 2
}
// the above lambda is equivalent to:
numbers.map(fun(param1) {
$1 * 2
})
thp
Syntax error: Unexpected token `.`, expected a new line at line 1:7