112 reject redundant phantom qualification

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

Code

// PIN: a phantom state qualified with the SAME module its base type already
// names is REDUNDANT and is refused (KORU116) with a teaching diagnostic
// ("bare `<!active>` already scopes to the base type's module `app/lib/db` —
// drop the qualifier"). One-canonical-spelling: there is exactly ONE way to
// write "app/lib/db's active on app/lib/db's Transaction" — the bare form
// (330_087-style base-type-module self-resolution). Contrast 330_087
// (qualifying a FOREIGN module's state on a primitive base — required, not
// redundant) and 690_037 (`Store<std/store:!taken>` — type home ≠ state home).
~import std/io
~import app/lib/db

// REDUNDANT: `*app/lib/db:Transaction` already names app/lib/db; re-qualifying
// the state `<app/lib/db:!active>` restates it. Should be `<!active>` (bare).
~tor finish { t: *app/lib/db:Transaction<app/lib/db:!active> }

~proc finish|zig {
    return;
}

~app/lib/db:begin(): tx |> finish(t: tx) |> std/io:print.ln("ok")

input.kz

Supporting Files

// A module that declares a resource TYPE with intrinsic typestate. `active` is
// app/lib/db's own state, issued bare in-module (self-resolves to app/lib/db).
const std = @import("std");
const Transaction = struct { id: i32 };

~pub tor begin { } -> *Transaction<active!>

~proc begin|zig {
    const t = std.heap.page_allocator.create(Transaction) catch unreachable;
    t.* = .{ .id = 1 };
    return t;
}

lib/db.kz

Actual compiler output

error[KORU116]: redundant phantom qualifier: bare '<!active>' already scopes to the base type's module 'app/lib/db' — drop the qualifier
  --> tests/regression/300_ADVANCED_FEATURES/330_PHANTOM_TYPES/330_112_reject_redundant_phantom_qualification/input.kz:13:0
    |
 13 | // the state `<app/lib/db:!active>` restates it. Should be `<!active>` (bare).
    | ^
  hint: write <!active>; qualify a phantom only when its home differs from the type's

Frontend must reject with:

CONTAINS redundant

Flows

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begin

Test Configuration

MUST_ERROR

← 111 reject consume obligation in output 113 named capture obligation undischarged →