In Sage, functions are declared with the fun keyword.
fun add(a: Int, b: Int): Int {
return a + b;
}
println(add(2, 3));
Output:
5
5
Alternate Syntax#
Functions may also be defined with a single expression and the = operator.
fun add(a: Int, b: Int): Int = a + b;
println(add(2, 3));
Output:
5
5
Function Types#
Functions can be passed as arguments to other functions. The type of a function is written as fun(T1, T2, ..., Tn) -> T.
// Define `f` as a function that takes two ints and
// returns another int.
// Call it on the next two arguments.
fun test(f: fun(Int, Int) -> Int, a: Int, b: Int): Int {
return f(a, b);
}
// The function to pass to `test`
fun add(a: Int, b: Int): Int = a + b;
// Call `test` with our other function!
println(test(add, 2, 3));
Output:
5
5
Templates#
Functions may also take template parameters:
fun first<A, B>(a: (A, B)): A = a.0;
fun second<A, B>(a: (A, B)): B = a.1;
println(first<Int, Float>((2, 3.0)));
println(second<Int, Float>((2, 3.0)));
Output:
2
3
2
3