Scripting:Syntax

From STNE Wiki

This page describes the syntax of the STNE scripting engine.

As with C style languages, a statement is always terminated by a semicolon. A statement can be a function call, variable declaration or assignment.

Variable declaration

Variables are declared with the code 'Var [VarName] As VarType'. This is best illustrated with a small example:

Var WelcomeMessage As String; // Declares a variable named 'WelcomeMessage' of type String
Var DataTable As CTable;      // Declares a variable named 'DataTable' of type CTable


/* It is also possible to immediately assign a value when declaring variables */

Var WelcomeMessage As String = "Hello galaxy!"; // Declares a string and assigns it a value
Var DataTable      As CTable = New CTable();    // Declares a variable and assigns a newly created CTable to it
Var InfoTable      As New CTable();             // Also declares a variable and assigns a newly created CTable to it, but with less code

Conditional statements

It is possible to wrap code in conditional code blocks by using If, Else and ElseIf statements. If and ElseIf statements are followed by a boolean expression between round brackets. Code blocks following the If/Else/ElseIf statements have to be wrapped in curly brackets.

An example:

If (x <= 5) {
  WriteLine("Five or less.");
}
ElseIf (x <= 10) {
  WriteLine("More than five.");
  WriteLine("Ten or less.");
}
Else {
  WriteLine("More than ten.");
}

Loops

There are a few kind of loop statements: For, For Each, While and Do...While loops. They work similar to For, While and Do...While loops in other programming languages. The For loop will increment a specified counter by a given step until a certain value is reached. The For Each loop iterates all elements of a class implementing ICollection. You can recognize classes implementing this interface by the few methods in the interface. Note that using For Each on a hash table returns DictionaryEntry structs and not the keys or values. The While and Do...While loops continue to loop while a boolean expression results in True. The difference between the While and Do...While loops is when the boolean expression is evaluated. While loops check the expression at the beginning of each iteration, Do...While loops check the expression at the end of each iteration. As a result, Do...While loops are always executed at least once.

An example:

/* This will print each number from 0 to 10. 0 and 10 included. */
Var i As Integer;
For (i = 0 To 10) {
  WriteLine(i);
}

/* This will print all even numbers from 10 to 0. 0 and 10 included. */
Var i As Integer;
For (i = 10 To 0 Step -12) {
  WriteLine(i);
}

/* This will print the name of each ship in the SRS report of the ship with NCC 123456 */
Var MyShip As New CMyShip(123456);
Var Current As CShip;
For (Each Current In MyShip.SRS) {
  WriteLine(Current.Name);
}

/* This will print each number from 0 to 10. 0 and 10 included. */
i = 0;
While (i <= 10) {
 WriteLine(i++);    // i++ increases i by one and returns the old value, see Operators for details.
}

/* This will also print each number from 0 to 11. 0 and 11 included! */
i = 0;
Do {
 WriteLine(i++);
}
While(i <= 10)