1 Answers
The Zero one infinity rule is a rule of thumb in software design proposed by early computing pioneer Willem van der Poel. It argues that arbitrary limits on the number of instances of a particular type of data or structure should not be allowed. Specifically, an entity should either be forbidden entirely, only one should be allowed, or any number of them should be allowed. Although various factors outside that particular software could limit this number in practice, it should not be the software itself that puts a hard limit on the number of instances of the entity.
Allow none of foo, one of foo, or any number of foo.
The only reasonable numbers are zero, one and infinity.
Examples of this rule may be found in the structure of many file systems' directories :