Question

I am working on a small library that enables users of a website to search and filter the records that are displayed. I’m currently designing the API but I need a good alternative name for these sort of filters that end-users use.

Our collection of libraries roughly conforms to the existing Zend naming conventions. That is, <Library>/Filter namespace is used for the kind of filters that you can attach to form elements to filter the contents of variables. So, I need another name for the kind of filters that you use to filter records or collections of objects.

Answer 1

Predicate

Informally, a predicate is a statement that may be true or false depending on the values of its variables. It can be thought of as an operator or function that returns a value that is either true or false. For example, predicates are sometimes used to indicate set membership: when talking about sets, it is sometimes inconvenient or impossible to describe a set by listing all of its elements. Thus, a predicate P(x) will be true or false, depending on whether x belongs to a set.