#24 reflective: isInstance dla wildcards

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ranides5 年之前創建 · 2 條評論
ranides commented 5 年之前

net.ranides.assira.reflection.impl.RWClassTest#testParent

Rzecz w tym, że my tu mamy unresolved params, bo przekazujemy obiekt (i type erasure wchodzi). A to oznacza, że NIE powinno tutaj nic matchować na ten moment, o ile nie zrobimy obsługi prawdziwej dla atrybutu IAttribute.RESOLVED.

Tylko w takim wypadku możemy być "tolerancyjniejsi" względem erasure'owanych typów i je przepuszczać

Test dla wildcardów powinien opierać się na isSuper/isSubclass dla TypeToken jako argumentu, bo on zawiera całe info na temat typu testowanego

//        System.out.printf("%s%n", ic1);
//        assertTrue(ic1.isInstance(new ArrayList<Float>())); 
`net.ranides.assira.reflection.impl.RWClassTest#testParent` Rzecz w tym, że my tu mamy unresolved params, bo przekazujemy obiekt (i type erasure wchodzi). A to oznacza, że NIE powinno tutaj nic matchować na ten moment, o ile nie zrobimy obsługi prawdziwej dla atrybutu `IAttribute.RESOLVED`. Tylko w takim wypadku możemy być "tolerancyjniejsi" względem erasure'owanych typów i je przepuszczać Test dla wildcardów powinien opierać się na isSuper/isSubclass dla TypeToken jako argumentu, bo on zawiera całe info na temat typu testowanego ``` // System.out.printf("%s%n", ic1); // assertTrue(ic1.isInstance(new ArrayList<Float>())); ```
ranides commented 3 年之前
所有者

idea is simple, we : net.ranides.assira.reflection.impl.RCompareUtils#isSuper should deduce argument "raw". It should be true only if:

raw = raw || !isuper.isResolved() || !iclass.isResolved(); 
idea is simple, we : net.ranides.assira.reflection.impl.RCompareUtils#isSuper should deduce argument "raw". It should be true only if: ``` raw = raw || !isuper.isResolved() || !iclass.isResolved(); ```
ranides3 年之前 關閉
ranides 在代碼提交 3 年之前 中引用了該問題
ranides commented 3 年之前
所有者

We preserve information attribute if type is resolved. We are permisive when we check type relations (equal, super, subclass) if one of the types is not resolved.

All in all, we should be permisive because compiler does the same, because of type erasure. It is classical unchecked cast, it is allowed by Java, so let's allow it too.

We could do the opposite: return false if we are not sure. Or even better: throw exception with information, that we are unable to check. Maybe we can implement that in some "strict mode", but at this moment, such strict mode seems to be useless.

todo: strict mode

We preserve information attribute if type is resolved. We are permisive when we check type relations (equal, super, subclass) if one of the types is not resolved. All in all, we should be permisive because compiler does the same, because of type erasure. It is classical unchecked cast, it is allowed by Java, so let's allow it too. We could do the opposite: return false if we are not sure. Or even better: throw exception with information, that we are unable to check. Maybe we can implement that in some "strict mode", but at this moment, such strict mode seems to be useless. todo: strict mode
ranides3 年之前 重新開啟
ranides 在代碼提交 3 年之前 中引用了該問題
ranides3 年之前 關閉
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