Variables

Variables are symbolically named storage for accessing and manipulating values. They are typically scoped to a region of code with a chosen manner of visibility, and are one of the fundamental building blocks to high-level programming languages.

Declaring Values

To declare a variable in Talos, start by using the let or the mut keyword, followed by the name of the variable. The let keyword is used to denote variables that are assigned only once (eg: immutable), and the mut keyword is for variables that can be reassigned (eg: mutable).

let x: Number = 5;     // Declare an immutable variable named 'x' with a value of '5'
mut y: String = "hi";  // Declare a mutable variable named 'y' with a value of "hi"

x = 42;     // This would result in an assignment exception at compile-time
y = "bye";  // Whilst this is accepted and 'y' will now have a value of "bye"

Talos also supports type inference and automatically resolves the type of a declared variable from its initializer.

// The variable 'x' is infered as 'List[Number]'
let x = [0, 1, 2];

Explicit Resources

Alongside the let and mut keywords, is the use declaration which declares a variable as a disposable resource. Such variables are immutable, and only available within their declaring scope (eg: cannot be exported). This is so that upon the closure of their encompassing scope, they are disposed of. For more information, see the explicit resource management section.