I found a statement (without explanation) that a language $A = 0^*$ is decidable. How is that possible? I mean, how would we build a Turing machine that would accept (or reject) a possibly infinite string of 0's? I also thought that maybe we could create an enumerator that would create all words from $0^*$ with increasing length, but I am not sure if we can.
So is $0^*$ a decidable language? And if so, why?