016 array literal subflow impl

// TEST: Array literal in subflow implementation
//
// Array literals work in regular comptime flows but fail in subflow implementations
// using the `~event = flow` syntax.
//
// This test mimics the compiler.kz coordinate pattern:
//   ~[abstract] event coordinate { ... }
//   ~coordinate = step1() | result r |> step2(values: [r.a, r.b, r.c])

const std = @import("std");

const Context = struct {
    id: u32,
};

// Abstract event with multiple contexts
~[comptime|abstract] event process { allocator: std.mem.Allocator }
| done u32

// Step 1: Create contexts
~[comptime] event setup {}
| ready { c0: Context, c1: Context, c2: Context }

~proc setup|zig {
    return .{ .ready = .{
        .c0 = .{ .id = 0 },
        .c1 = .{ .id = 1 },
        .c2 = .{ .id = 2 },
    } };
}

// Step 2: Process array of contexts
~[comptime] event consume { contexts: []const Context }
| consumed u32

~proc consume|zig {
    std.debug.print("[COMPTIME] Processing {} contexts\n", .{contexts.len});
    return .{ .consumed = @intCast(contexts.len) };
}

// THE KEY TEST: Subflow implementation with array literal
// This syntax (`~process = ...`) creates a subflow_impl
// Array literals inside subflow_impl flows emit incorrectly
~process = setup()
| ready r |> consume(contexts: [r.c0, r.c1, r.c2])
    | consumed c => done c

// Trigger the flow
~process(allocator: std.heap.page_allocator)
| done d |> report(count: d)

~[comptime] event report { count: u32 }

~proc report|zig {
    if (count == 3) {
        std.debug.print("PASS: subflow array literal works\n", .{});
    } else {
        std.debug.print("FAIL: expected 3, got {}\n", .{count});
    }
}