View source for Category:Wren-trait

{{library}}
'''Wren-trait''' is a module which provides the abstract classes: Comparable, Cloneable and CloneableSeq. The first of these enables child classes to easily support the basic comparison operators and the latter two enables such classes to identify themselves as ''cloneable'' given a suitable mechanism.

It also contains the wrapper classes: ByRef, ByKey, Const, Var and TypedVar. ByRef enables a value to be passed ''by reference'' to a method or function, ByKey enables a reference type object to be used as a Map key and Const represents a group of individually named read-only values.

Var represents a group of individually named read/write values. It can be used to simulate the creation of variables at runtime. It can also be used to allow variable names which would otherwise be illegal in Wren such as those which include non-ASCII characters.

TypedVar is similar to Var except that the simulated variables always retain the same type as they had when they were originally created.

It is the fifth in a series of modules (listed on the language's [[:Category:Wren|main page]]) designed to assist with writing Rosetta Code tasks so the same code does not have to be written or copy/pasted time and time again thereby bloating a task's script code unnecessarily. It is also small enough to be used by other modules in the series which are usually organized and written to avoid inter-dependencies.

To use it all you need to do is to copy the source code (in the [[:Category_talk:Wren-trait|talk page]]) to a text file called ''trait.wren'' and place this in the same directory as the importing script or module so the command line interpreter can find it.