state variable constraint violation

✓ Passing Passing: the compiler rejects this program as expected.

Code

// PINS: a state VARIABLE constraint is checked against the concrete state.
// `process` accepts `*Data<M'owned|borrowed>`; `gc-alloc` hands back
// `*Data<gc>`, which is neither member, so the call is refused and the
// diagnostic names both the constraint and the state that failed it.
~import app/data
~app/data:gc-alloc(): a |> app/data:process(d: a)

input.kz

Supporting Files

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

~pub tor gc-alloc {} -> *Data<gc>  // GC-managed, NOT owned or borrowed

~proc gc-alloc|zig {
    const allocator = std.heap.page_allocator;
    const d = allocator.create(Data) catch unreachable;
    d.* = Data{ .value = 42 };
    return d;
}

// Generic processor constrained to owned OR borrowed ONLY
~pub tor process { d: *Data<M'owned|borrowed> } -> *Data<M'owned|borrowed>

~proc process|zig {
    return d;
}

data.kz

// Generic processor constrained to owned OR borrowed ONLY

~pub tor process { data: *Data<M'owned|borrowed> } -> *Data<M'owned|borrowed>

~proc process|zig {
    return data;
}

processor.kz

Actual compiler output

error[KORU030]: Phantom state mismatch: expected 'M'owned|borrowed' but got 'app.data:gc' for argument 'd'
  --> tests/regression/300_ADVANCED_FEATURES/330_PHANTOM_TYPES/524_state_variable_constraint_violation/input.kz:6:0

❌ Compiler coordination error: Phantom semantic validation failed
   (set KORU_BACKEND_TRACE=1 for the backend return trace)

Must contain:

error[KORU030]

Flows

flow ~gc-alloc click a branch to expand · @labels scroll to their anchor

gc-alloc

Test Configuration

MUST_ERROR

← state variable constrained accepts state variable chaining →