Expressiveness is important. I remember many times reading logic and missing the little tinsy ! before a giant expression not making the quick flag in my mind raise indicating that this is a unless, not an if. In ruby the idea of the unless is not to save typing. In fact if !foo is easier to write than unless foo. However after a tad bit of getting used to it, you realize that it becomes immediately obvious when skimming the code what the operation is doing.
The idea is lets leave the brainpower for the hard problems, and not require you to use all that brainpower to figure out the plumbing.
The idea is lets leave the brainpower for the hard problems, and not require you to use all that brainpower to figure out the plumbing.