A guide to scripting within Classics Patch using its "Scripting Engine" plugin.

• Squirrel scripting language: http://squirrel-lang.org/
• Official documentation: http://squirrel-lang.org/squirreldoc/
• Valve Development Community documentation: https://developer.valvesoftware.com/wiki/Squirrel

Right now, the only scripting language Classics Patch supports is Squirrel 3.2.

Squirrel is a scripting language with C-like syntax designed for games.
It can be used for implementing new mechanics (such as new gamemodes) without having to code your own plugins for the patch.

Scripts are much more efficient and versatile than the engine's shell language.

Language	Syntax	Object-oriented	Dynamic types	Integer type	Float type	Boolean type	String type	Arrays	Type conversion	Global variables	Local variables	Control flow statements	Loop statements	Classes	Functions	Code nesting
SE1 shell	C-like	No	No	Signed 32 bits	Single precision	Integer type	Yes	Limited	Explicit	Yes	No	if, else, else if	N/A	N/A	Execution	Standard include "path" command; custom IncludeScript(<path>) function
Squirrel	C-like	Yes	Yes	Signed 64 bits	Single precision	Yes	Yes	Yes	Implicit, explicit	Yes	Yes	if, else, else if, switch-case	while, do-while, for, foreach	Yes	Definition, execution, lambdas	Custom IncludeScript(<path>) function

Scripting Engine extension implements specific libraries to allow interactions with the game and the engine via scripts.

Library	Squirrel table	Purpose
Entities	Entities	[UNFINISHED] Interactions with entities in the world.
File system	FileSystem	[UNFINISHED] Working with game files and binary/text data within them.
Input	Input	Input polling from keyboard, mouse and joysticks.
Messages	Message	Message boxes and other information output.
Network	Network	[UNFINISHED] Interactions with the currently running game.
Shell	Shell	Interactions with the engine shell.
Timer	Timer	Reading current game/frame time.
Utilities	Utils	Helper classes and functions, not strictly under the library namespace (global).
World	World	[UNFINISHED] Interactions with the current world.