003 flow purity

// Test that demonstrates flow purity concept
// Flows compose events - they don't execute code themselves
// This test verifies the AST structure supports purity tracking on flows

const std = @import("std");

// Pure event
~event add { x: i32, y: i32 }
| done { result: i32 }

~[pure]proc add {
    return .{ .done = .{ .result = x + y } };
}

// Event that composes other events (flow-like composition)
~event calculate { a: i32, b: i32, c: i32 }
| done { result: i32 }

~proc calculate {
    // Composition of pure operations - flow-like behavior
    const step1 = add_event.handler(.{ .x = a, .y = b });

    switch (step1) {
        .done => |d1| {
            const step2 = add_event.handler(.{ .x = d1.result, .y = c });
            switch (step2) {
                .done => |d2| {
                    return .{ .done = .{ .result = d2.result } };
                },
            }
        },
    }
}

~event print_result { n: i32 }
| done {}

~proc print_result {
    std.debug.print("Result: {}\n", .{n});
    return .{ .done = .{} };
}

~event main {}
| done {}

~proc main {
    const result = calculate_event.handler(.{ .a = 10, .b = 20, .c = 12 });

    switch (result) {
        .done => |d| {
            _ = print_result_event.handler(.{ .n = d.result });
        },
    }

    return .{ .done = .{} };
}

~main()
| done |> _