state variable constraint violation

✓ Passing This code compiles and runs correctly.

Code

// MUST_FAIL
// EXPECT: State variable constraint violation
//
// Test 524: Constrained state variable REJECTS invalid state
// Tests that M'owned|borrowed REJECTS states not in the constraint
//
// Key points:
// - data:process has d: *Data[M'owned|borrowed]
// - M is constrained to ONLY owned OR borrowed
// - [gc] is NOT in the constraint
// - Should fail at compile time with constraint violation error

~import "$app/data"

// ERROR: [gc] not in constraint M'owned|borrowed
~app.data:gc_alloc()
| allocated a |> app.data:process(d: a.data)  // ❌ ERROR: [gc] doesn't satisfy M'owned|borrowed
    | done |> _

input.kz

Error Verification

Actual Compiler Output

error[KORU030]: branch 'done' has payload but no binding
  --> structural_check:17:0

❌ Compiler coordination error: Incomplete branch coverage
error: CompilerCoordinationFailed
/Users/larsde/src/koru/tests/regression/300_ADVANCED_FEATURES/330_PHANTOM_TYPES/524_state_variable_constraint_violation/backend.zig:9413:17: 0x1023ea4af in emit (backend)
                return error.CompilerCoordinationFailed;
                ^
/Users/larsde/src/koru/tests/regression/300_ADVANCED_FEATURES/330_PHANTOM_TYPES/524_state_variable_constraint_violation/backend.zig:9497:28: 0x1023eb2b7 in main (backend)
    const generated_code = try RuntimeEmitter.emit(compile_allocator, final_ast);
                           ^

Imported Files

const std = @import("std");
const Data = struct { value: i32 };

~pub event gc_alloc {}
| allocated *Data[gc]  // GC-managed, NOT owned or borrowed

~proc gc_alloc {
    const allocator = std.heap.page_allocator;
    const d = allocator.create(Data) catch unreachable;
    d.* = Data{ .value = 42 };
    return .{ .allocated = d };
}

// Generic processor constrained to owned OR borrowed ONLY
~pub event process { d: *Data[M'owned|borrowed] }
| done *Data[M'owned|borrowed]

~proc process {
    return .{ .done = d };
}

data.kz

// Generic processor constrained to owned OR borrowed ONLY

~pub event process { data: *Data[M'owned|borrowed] }
| done *Data[M'owned|borrowed]

~proc process {
    return .{ .done = data };
}

processor.kz

Test Configuration

MUST_FAIL

← state variable constrained accepts state variable chaining →