How to programatically determine if a function is isolated or not in Ballerina?

Question

In my Ballerina code, I need to validate whether a given Ballerina function is isolated within my logic. What would be the recommended way to do that?

Answer 1

isolated is part of the type. you can check for is isolated function as follows.

import ballerina/io;

public function f1() returns int => 1;
public isolated function f2() returns int => 1;

public function main() {
    boolean isolatedFn = f1 is isolated function () returns int;
    io:println(isolatedFn);

    // should be possible, but not allowed atm, param/return types have to match
    io:println(f1 is isolated function);

    function f = f1;
    io:println(f is isolated function);
    io:println(<function> f2 is isolated function);
}

Please note that this check will be true for functions that are inferred as isolated(https://ballerina.io/learn/by-example/inferring-isolated/) as well.