Why would a language NOT use Short-circuit evaluation?

Question

Why would a language NOT use Short-circuit evaluation? Are there any benefits of not using it?

I see that it could lead to some performances issues... is that true?

Answer 1

I'd say it's valid for readability issues; if someone takes advantage of short circuit evaluation in a not fully obvious way, it can be hard for a maintainer to look at the same code and understand the logic.

If memory serves, erlang provides two constructs, standard and/or, then andalso/orelse . This clarifies intend that 'yes, I know this is short circuiting, and you should too', where as at other points the intent needs to be derived from code.

As an example, say a maintainer comes across these lines:

if(user.inDatabase() || user.insertInDatabase()) 
    user.DoCoolStuff();

It takes a few seconds to recognize that the intent is "if the user isn't in the Database, insert him/her/it; if that works do cool stuff".

As others have pointed out, this is really only relevant when doing things with side effects.