// Multi-instance closures: each capturing closure gets its own heap env
import Std::Io::{PrintLine, PrintInt};
import Std::Test::{Test_AssertEqInt, Test_Pass};

func MakeAdder(base: int) -> func(int) -> int {
    return |a: int| -> int {
        return a + base;
    };
}

func Apply(f: func(int) -> int, x: int) -> int {
    return f(x);
}

func Main() -> int {
    let a10: func(int) -> int = MakeAdder(10);
    let a20: func(int) -> int = MakeAdder(20);

    // Independent instances — not a single global env
    Test_AssertEqInt(a10(1), 11);
    Test_AssertEqInt(a20(1), 21);
    Test_AssertEqInt(a10(5), 15);
    Test_AssertEqInt(Apply(a20, 3), 23);

    // Capture-less still works
    let add: func(int, int) -> int = |x: int, y: int| -> int {
        return x + y;
    };
    Test_AssertEqInt(add(2, 3), 5);

    PrintInt(a10(1));
    PrintLine("");
    PrintInt(a20(1));
    PrintLine("");
    Test_Pass("multi_closure");
    return 0;
}