004 cleanup obligation escape

✓ Passing This code compiles and runs correctly.

Code

// ============================================================================
// VERIFIED REGRESSION TEST - DO NOT MODIFY WITHOUT DISCUSSION
// ============================================================================
// Test 513: Cleanup obligation escape
// Tests that semantic phantom checker detects cleanup obligations not met
// Demonstrates: ! marker for states requiring cleanup before disposal
// Expected: Should FAIL with "cleanup obligation not met" error

~import "$std/io"
~import "$app/fs"

// Open a file with opened! state
// The ! marker means this state requires cleanup (calling app.fs:close)
// before the flow terminates
~app.fs:open(path: "test.txt")
| opened |> _  // ERROR: Flow ends with *File[opened!] not cleaned up!

// This SHOULD fail because:
// 1. app.fs:open returns *File[opened!]
// 2. The flow terminates (_) without calling app.fs:close
// 3. The cleanup obligation is not met

// To fix, should do:
// ~app.fs:open(path: "test.txt")
// | opened f |> app.fs:close(file: f.file)
//     | closed |> std.io:println(text: "File closed properly")

input.kz

Error Verification

Expected Error Pattern

Backend should fail - no disposal event available or multiple disposal options

Actual Compiler Output

[PHASE 2.4] Calling run_pass for transforms\n[PHASE 2.5] Executing comptime_main() - running comptime flows
[PHASE 2.5] Comptime flows complete (36 items)
[PHASE 2.6] Rescanning transformed AST (36 items)
[PHASE 2.6] Rescan complete: 27 comptime events found
  [0] std.compiler:requires
  [1] std.compiler:flag.declare
  [2] std.compiler:command.declare
  [3] std.compiler:coordinate
  [4] std.compiler:context_create
  [5] std.io:print.ln
  [6] std.io:print.blk
  [7] std.testing:test
  [8] std.testing:validate_mocks
  [9] std.testing:test.with_harness
  [10] std.testing:test.harness
  [11] std.testing:assert
  [12] std.testing:test.property.equivalent
  [13] std.deps:deps
  [14] std.deps:requires.system
  [15] std.deps:requires.zig
  [16] std.control:if
  [17] std.control:for
  [18] std.control:capture
  [19] std.control:const
  [20] std.build:requires
  [21] std.build:variants
  [22] std.build:config
  [23] std.build:command.sh
  [24] std.build:command.zig
  [25] std.build:step
  [26] std.template:define
error[KORU030]: branch 'opened' has payload but no binding
  --> structural_check:16:0

❌ Compiler coordination error: Incomplete branch coverage
error: CompilerCoordinationFailed
/Users/larsde/src/koru/tests/regression/300_ADVANCED_FEATURES/330_PHANTOM_TYPES/330_004_cleanup_obligation_escape/backend.zig:10917:17: 0x10071e433 in emit (backend)
                return error.CompilerCoordinationFailed;
                ^
/Users/larsde/src/koru/tests/regression/300_ADVANCED_FEATURES/330_PHANTOM_TYPES/330_004_cleanup_obligation_escape/backend.zig:11001:28: 0x10071f1bf in main (backend)
    const generated_code = try RuntimeEmitter.emit(compile_allocator, final_ast);
                           ^

Imported Files

// Library module: fs
// Defines filesystem operations with cleanup obligations

const std = @import("std");

// File type with phantom states
const File = struct {
    handle: i32,
};

// Open a file - returns opened! state (requires cleanup)
~pub event open { path: []const u8 }
| opened { file: *File[opened!] }

~proc open {
    std.debug.print("Opening file: {s}\n", .{path});
    const allocator = std.heap.page_allocator;
    const f = allocator.create(File) catch unreachable;
    f.* = File{ .handle = 42 };
    return .{ .opened = .{ .file = f } };
}

// Close a file - accepts opened state, returns closed state
~pub event close { file: *File[!opened] }
| closed {}

~proc close {
    std.debug.print("Closing file\n", .{});
    return .{ .closed = .{} };
}

fs.kz

Test Configuration

MUST_FAIL

← 003 unknown phantom module 005 cleanup obligation satisfied →