Iteration

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iteration.fl

i32 main() {
    [3]i32 values = [10, 20, 30];

    // A single binding receives each index (usize).
    for index := range values {
        stdoutln(values[index]);
    }

    // Two inferred bindings: usize index and i32 value.
    for (index, value) := range values {
        stdoutln(index);
        stdoutln(value);
    }

    // Typed declarations use '='. Each value is an independent copy.
    for (u32 index, i32 value) = range values {
        value++;
        stdoutln(value);
    }

    // '_' discards a binding.
    i32 total = 0;
    for (_, value) := range values {
        total = total + value;
    }
    if total != 60 { return 1; }

    // Use a counted loop to modify the original array.
    loop usize index = 0; index < values.len(); index++ {
        if index == 1 { proceed; } // still executes index++
        values[index]++;
    }
    if values[0] != 11 or values[1] != 20 or values[2] != 31 { return 2; }

    // Inclusive bounds are valid for a numeric counter.
    loop u32 x = 1; x <= 3; x++ {
        stdoutln(x);
    }
    return 0;
}