subflow immediate

// ============================================================================
// VERIFIED REGRESSION TEST - DO NOT MODIFY WITHOUT DISCUSSION
// ============================================================================
// Test: Immediate subflow with field mapping
// Feature: ~event_name = branch { output_field: input_field }
// Verifies: Input fields are accessible and mapped to output correctly
// ============================================================================

~import "$std/io"

// Event: takes a name, produces a greeting message
~event greet { name: []const u8 }
| greeting { message: []const u8 }

// Subflow implementation: maps input field 'name' to output field 'message'
~greet = greeting { message: name }

// Test: call greet with "World" and print the resulting message
~greet(name: "World")
| greeting g |> std.io:print(text: g.message)