NUT & GNUT - Squirrel

About Squirrel

Squirrel is a programming language similar to Lua, but uses a C like syntax. In Source Squirrel is used as one of the scripting languages in the VScript scripting system.

This explains a version of Squirrel suspected to be modified by Respawn. To learn about Squirrel for other, non-Respawn games, check Squirrel - Valve Developer Community.

Variables

A Varaible can be declared by specifying it's type, then it's name, an equals sign, then it's value, like so:

int x = 5;

Then, it can be used by typing it's name.

printt(x);

Data Types

There are multiple base data types for Squirrel, and some data types from source.

Data Type	Description
bool	A boolean value, true or false.
int
float
vector	An element with x, y, and z components.
array<T>	An array of dynamic value, of type T.
struct	A class alternative without functions, explained below.
var	Can contain anything, but cannot be used as input to functions with input types that are not 'var'.
entity	Is used for anything in the game world, except UI, which should use var, as their type is unknown.

Functions and Globalization

Functions are the primary way to execute code. All code that is not a variable deceleration must be inside a function.

Declaration example:

// Function syntax is <return type> function functionName(type p1, type p2)
// Function that gives back an int
// This example does NOT work in MP and will return an error.
int function CoolFunction(int x, int y) {
    return x * y + x * x;
}
// function that doesn't return back anything
void function Mod_SetMaxHealth(int newMaxHealth) {
    entity player = GetPlayerArray()[0];
    if (newMaxHealth <= 0) return;
    player.SetMaxHealth(newMaxHealth);
}

Structs

Structs are used either as a class alternative or for grouping variables in a singleton method.

Declaring example:

Declaring a regular struct

struct SimpleStruct {
    int x = 5;
    float y = 2.5;
    array<int> z = [7, 8, 9, 10]
}
// Creating a struct is done like declaring a variable;
// First the struct's name, then the variable's name.
// --- EXAMPLE ---
SimpleStruct example;
// Accessing struct properties can be done using a dot after the name of the instance.
// --- EXAMPLE ---
example.x = 6; 
example.y = 3.5;
example.z[0] = 6;

Declaring a Singleton struct

struct {
    int x = 5;
    float y = 2.5;
    array<int> z = [1, 2, 3,
} singletonStruct
// A singleton struct just makes one instance of itself using the name-
// -after it's contents. Unlike a regular struct, the name is inserted-
// -**AFTER** the declaration of the struct's properties.
// Accessing struct properties can be done using a dot after the name of the struct.
// --- EXAMPLE ---

Sources:

• https://developer.valvesoftware.com/wiki/Squirrel