It’s required to satisfy the verifiability constraints for the generated IL. Note that unverifiable doesn’t necessarily mean incorrect. It works just fine without the box instruction as long as its security context allows running unverifiable code. Verification is conservative and is based on a fixed rule set (like reachability). To simplify things, they chose not … Read more
The = “operator” in Prolog is actually a predicate (with infix notation) =/2 that succeeds when the two terms are unified. Thus X = 2 or 2 = X amount to the same thing, a goal to unify X with 2. The == “operator” differs in that it succeeds only if the two terms are … Read more
Set __contains__ makes checks in the following order: ‘Match’ if hash(a) == hash(b) and (a is b or a==b) else ‘No Match’ The relevant C source code is in Objects/setobject.c::set_lookkey() and in Objects/object.c::PyObject_RichCompareBool().
Yes, class tokens are unique (for any given classloader, that is). I.e. you will always get a reference to the same physical object within the same classloader realm. However, a different classloader will load a different class token, in conjunction with the fact that the same class definition is deemed different when loaded by two … Read more
I think the above answer deserves a few words of explanation here nevertheless. A short note in advance: Arithmetic expressions in Prolog are just terms (“Everything is a term in Prolog”), which are not evaluated automatically. (If you have a Lisp background, think of quoted lists). So 3 + 4 is just the same as … Read more
Unlike Java, C# strings override the == operator: if (str1 == str2) If you want a case-insensitive comparison: if (string.Equals(str1, str2, StringComparison.OrdinalIgnoreCase))
Rails deliberately delegates equality checks to the identity column. If you want to know if two AR objects contain the same stuff, compare the result of calling #attributes on both.
Use the getTime() method. It will check the numeric value of the date and it will work for both the greater than/less than checks as well as the equals checks. EDIT: if (d1.getTime() === d2.getTime())
There are three concepts to grasp when trying to understand id, hash and the == and is operators: identity, value and hash value. Not all objects have all three. All objects have an identity, though even this can be a little slippery in some cases. The id function returns a number corresponding to an object’s … Read more