006 event purity

// Test event purity computation
// Event purity is computed from ALL proc implementations
// If ALL procs are pure -> event is pure
// If ANY proc is impure -> event is impure

~import "$std/io"

const std = @import("std");

// Event with single pure implementation -> pure event
~event pure_add { x: i32, y: i32 }
| done { result: i32 }

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

// Event with single impure implementation -> impure event
~event impure_log { msg: []const u8 }
| done {}

~proc impure_log {
    std.debug.print("[LOG] {s}\n", .{msg});
    return .{ .done = .{} };
}

// Flow that composes pure and impure events
~event compute { a: i32, b: i32 }
| done { result: i32 }

~compute = pure_add(x: a, y: b)
| done d |> impure_log(msg: "Computed!")
    | done |> done { result: d.result }

~compute(a: 20, b: 22)
| done d |> std.io:print.ln("Result: {{ d.result:d }}")