Category:Elena: Difference between revisions

All referring entities in the language are objects. A variable is a reference to the object allocated in the program heap. The literal and numeric constants are references to the objects allocated in the static memory.

 

 

Any ELENA program or library consists of modules (files with .NL extension) containing

(the new module namespace consists of the root one plus the folder relative path)

 

 

As in the most of dynamic object-oriented languages the main way to interact with objects in ELENA is sending a message. Unlike others the message name is structured and consists of a verb, a signature and a parameter counter. The verb defines a message action, for example read or write some data. There are only limited set of possible verbs (e.g. eval[uate], add, set, get, run, seek and so on). In general the signature is user defined and describes the message parameters. It can be used to define some custom

 

 

 

ELENA is an object-oriented language, so to create a program we have to declare new classes.

#static SingletonClass = DerivedClass new &field:0 &field:0.

 

 

ELENA code block consists of a sequence of statements. The block is enclosed in square brackets and may contain nested sub code blocks (which in fact are inline action classes). The statement terminator is a dot.

 

 

ELENA like Smalltalk does not support any special language constructs to implement the conditional branching. Instead special Boolean symbols (system’true and system’false) are used. All conditional operations should return these symbols as a result.