Re:Why did we ever think a student's first programming langu...
by thaumasiotes on Sunday June 27, 2021 @12:11PM
(#27652723)
> If/else expressions are in principle free to evaluate both branches, but that would be needless.
This is true only in a pure functional language; if you admit the existence of side effects, then it is a crucial part of an if statement that the code associated with the other branch is never executed.
My point is just that it makes no sense to say "some languages have no form of if statement; for example, Haskell doesn't have the concept of one thing happening after something else". That example is untrue. But if it were true, it still would not interfere with Haskell's ability to have an if statement. Thus, defending Haskell's ability to run one statement after another statement is unnecessary to refute the claim; the claim never worked in the first place.
This is true only in a pure functional language; if you admit the existence of side effects, then it is a crucial part of an if statement that the code associated with the other branch is never executed.
My point is just that it makes no sense to say "some languages have no form of if statement; for example, Haskell doesn't have the concept of one thing happening after something else". That example is untrue. But if it were true, it still would not interfere with Haskell's ability to have an if statement. Thus, defending Haskell's ability to run one statement after another statement is unnecessary to refute the claim; the claim never worked in the first place.