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.error { color:#AA0000; }</style></head><body><p>Is that assumption correct?</p>
<pre><code class="swift">// Module A
public protocol SQLiteValue {
init(statement: SQLiteStatement, columnAt index: Int) throws
func bind(to statement: SQLiteStatement, at index: Int) throws
}
// Module B
protocol SQLiteLoggable : SQLiteValue {
var logDescription: String { get }
}
</code></pre>
<p>I could not follow your example there. If <code>SQLiteLoggable</code> is from module <code>B</code> than this should be an error in my opinion. Otherwise <code>open</code> would have less meaning on protocols, because you always could create an empty protocol that has a super <code>public protocol</code> which you’re not allowed to conform to in module B. This would be a silly workaround to being able to conform to it <code>SQLiteValue</code> indirectly without any further requirement like in <code>SQLiteValueConvertible</code>.</p>
<p>That said, it makes no sense to me to allow that, because it’s simply a workaround to conform to a protocol which <code>public-but-not-open</code> tries to prevent.</p>
<pre><code class="swift">// Module X
public protocol A {}
open protocol AA : A { func foo() } // Fine
// Module Y
struct B : A {} // Error
struct B : AA { func foo() { .. } } // Okay
protocol C : A {} // Error because `struct B : C` would equal `struct B : A`
protocol CC : AA {} // Should work even empty, because we have more requirement from `AA`
</code></pre>
<p><code>public</code> should have a consistent meaning across all types from module A in module B, which is ‘not allowed to sub-type from’ and in case of protocols additionally ‘not allowed to conform to’.</p></body></html>