Category:Elena: Difference between revisions

ELENA is a general-purpose, object-oriented, polymorphic language with late binding. It features message dispatching/manipulation, dynamic object mutation, a script engine / interpreter and mix-ins.

 

 

To create a simple console program we have to declare the **program** symbol in the project root namespace:

**Console::write** method is similar to **writeLine** except that it writes to the output screen without a new line character.

 

 

A variable can be declared in an assignment statement starting with **var** attribute:

system'startUp(5)

 

 

Boolean type is used in conditional operations and may accept only two Boolean literals - **true** and **false**.

false==true is false

 

 

The most used numeric types in ELENA are 32-bit signed integer number (represented by **IntNumber**), 64-bit signed integer number (represented by **LongNumber**) and 64-bit floating-point number (represented by **RealNumber**):

Real number - 2.3456

 

 

**LiteralValue** is used to store the text encoded in UTF-8. LiteralValus is read-only collection of **CharValue** classes each representing UTF-32 symbol. *Note that one character may be encoded with more than one byte!*.

The last character of Привет is т

 

 

It is possible to declare a dynamic or static array.

dynamic array 1,b,2.3

 

 

ELENA supports basic arithmetic operations with integer and floating-point numbers:

12 + 5 * 2.3 = 23.5

 

 

Conditional statement in ELENA are defined as follows:

].

 

 

Everything in ELENA is a class. So to implement some tasks we will have to declare our own classes.

 

 

Let's create a simple class :

*Note that in ELENA a class is an object itself and can be used by like any other object*

 

 

We may inherit our class. When the parent is not explicitly declared - the class inherits *system'Object* super class

I'm a Child Class.

 

 

It is possible to declare the private methods which cannot be called outside the class.

system'startUp(5)

 

 

In normal case the class fields cannot be accessed outside the class. That's why we may declare a special method to access it:

].

 

We may use try-catch statement to handle the possible exceptions: