short-circuiting

If I have the following ... a OrElse b ... and a is True then clearly b is never evaluated. But if I add an Or , then what? a OrElse b Or c Does/should c get evaluated? And what if I put in some brackets? Apologies if this is basic. Of course I can test for the answer myself but I can't find this question answered here or elsewhere. Lots of questions dealing with Or versus OrElse but nothing dealing with Or with OrElse This is an operator precedence problem. The relevant documentation is here: http://msdn.microsoft.com/en-us/library/fw84t893.aspx?ppud=4 The important excerpts: Operators with

How can I tell if OCaml recognizes a particular function as tail-recursive? In particular, I want to find out if the OCaml compiler recognizes Short-circuited operators and tail recursion Thanks to Jeffrey's answer below, I tried this with the simple function let rec check_all l = match l with | [] -> true | hd :: tl -> hd && check_all tl and indeed, it does optimize to: camlTest__check_all_1008: .cfi_startproc .L102: cmpl $1, %eax je .L100 movl (%eax), %ebx cmpl $1, %ebx je .L101 movl 4(%eax), %eax jmp .L102 .align 16 .L101: movl $1, %eax ret Starting from OCaml 4.03, and despite the typo in

Does haskell have a parallel "and" method parAnd :: Bool -> Bool -> Bool such that (a `parAnd` b) will spark the evaluation of a and b in parallel and return false as soon as either a or b evaluates to false (and not wait for the other one)? Is there some way to implement such a thing? Normally, this is not possible. You can do something like a `par` b `pseq` (a && b) but if b evaluates to False , a is still fully evaluated. However, this is possible with the unambiguous choice operator created by Conal Elliott for his Functional Reactive Programming (FRP) implementation. It's available on

Given a container of boolean values (An example is std::vector<bool> ), is there a standard function that returns true if all the values are true ("and") or true if at least one value is true ("or"), with short circuit evalutation ? I digged trough www.cplusplus.com this morning but couldn't find anything close. You can implement by: AND: std::find(vector.begin(), vector.end(), false) == vector.end() // all the values are true OR: std::find(vector.begin(), vector.end(), true) != vector.end() //at least one value is true is there a standard function that returns true if all the values are true

When using the ?? operator in C#, does it short circuit if the value being tested is not null? Example: string test = null; string test2 = test ?? "Default"; string test3 = test2 ?? test.ToLower(); Does the test3 line succeed or throw a null reference exception? So another way to phrase the question: Will the right hand expression of the ?? operator get evaluated if the left hand is not null? Yes, it says so in the C# Language Specification (highlighting by me): A null coalescing expression of the form a ?? b requires a to be of a nullable type or reference type. If a is non-null, the result