Variables

Like in most programming languages, a variable in LENS is a lexical name that represents a value of a particular type. LENS supports mutable and immutable variables.

Mutable variables

Mutable variables are defined using the var keyword, followed by an expression to initialize the variable with:

var one = 1
var three = one + 2
var str = "hello world"

A mutable variable can also be declared by specifying a type. Then the default value for a type is used:

var a : string    // ""
var b : int       // 0
var c : Point     // Point(0, 0)

Immutable variables

Immutable variables are defined using the let keyword. They ensure that the value is assigned only once and will not change over time. Unlike a constant in C#, an immutable variable may be initialized with an expression evaluated during runtime.

let x = 1 + 2
let y = doStuff ()

Immutable variables cannot be passed to a function as a ref argument.