A comparison between an object specifier and a test object.
- macOS 10.0+
Instances of this class represent a Boolean expression; they evaluate an object specifier and compare the resulting object to another object using a given comparison method. For more information on
NSSpecifier, see the method description for its sole public method, its initializer,
NSSpecifier object is properly initialized, it holds two objects:
A “value” or “test” object used as the basis of the comparison; this object can be a regular object or object specifier (such as “blue” in “words whose color is blue”).
An object specifier evaluating to the container (“words”).
The instance also encapsulates a selector identifying the method performing this comparison. The informal protocol NSComparisonMethods defines a set of comparison methods useful for this purpose, while NSScriptingComparisonMethods describes additional methods you may need to use for scripting.
The test object is compared, using the selector, against each object in the container. Specifiers in these tests usually have
container invoked on their topmost container.
You should rarely need to subclass