Squirrel (programming language)
Squirrel is a high level imperative, object-oriented programming language, designed to be a lightweight scripting language that fits in the size, memory bandwidth, and real-time requirements of applications like video games and embedded systems.
Paradigm | Multi-paradigm: scripting, imperative, functional, object-oriented |
---|---|
Designed by | Alberto Demichelis |
First appeared | September 6, 2003 |
Stable release | 3.1
/ March 27, 2016 |
Typing discipline | Dynamic |
OS | Cross-platform |
License | MIT license |
Filename extensions | .nut |
Website | squirrel-lang |
Influenced by | |
C++, JavaScript, Lua, Python | |
Influenced | |
MiniD |
MirthKit, a simple toolkit for making and distributing open source, cross-platform 2D games, uses Squirrel for its platform.[1] It is used extensively by Code::Blocks for scripting and was also used in Final Fantasy Crystal Chronicles: My Life as a King.[2][3] It is also used in Left 4 Dead 2, Portal 2 and Thimbleweed Park for scripted events and in NewDark, an unofficial Thief 2: The Metal Age engine update, to facilitate additional, simplified means of scripting mission events, aside of the regular C scripting.[4]
Language features
- Dynamic typing
- Delegation
- Classes, inheritance
- Higher order functions
- Generators
- Cooperative threads (coroutines)
- Tail recursion
- Exception handling
- Automatic memory management (mainly reference counting with backup garbage collector)
- Weak references
- Both compiler and virtual machine fit together in about 7k lines of C++ code
- Optional 16-bit character strings
Syntax
Squirrel uses a C-like syntax.
- Factorial in Squirrel
function factorial(x)
{
if (x == 0) {
return 1;
}
else {
return x * factorial(x-1);
}
}
- Generators
function not_a_random_number_generator(max) {
local last = 42;
local IM = 139968;
local IA = 3877;
local IC = 29573;
for(;;) { // loops forever
yield (max * (last = (last * IA + IC) % IM) / IM);
}
}
local randtor = not_a_random_number_generator(100);
for(local i = 0; i < 10; i += 1)
print(">"+resume randtor+"\n");
- Classes and inheritance
class BaseVector {
constructor(...)
{
if(vargv.len() >= 3) {
x = vargv[0];
y = vargv[1];
z = vargv[2];
}
}
x = 0;
y = 0;
z = 0;
}
class Vector3 extends BaseVector {
function _add(other)
{
if(other instanceof ::Vector3)
return ::Vector3(x+other.x,y+other.y,z+other.z);
else
throw "wrong parameter";
}
function Print()
{
::print(x+","+y+","+z+"\n");
}
}
local v0 = Vector3(1,2,3)
local v1 = Vector3(11,12,13)
local v2 = v0 + v1;
v2.Print();
Applications
Non-game applications using Squirrel
Games using Squirrel
- Left 4 Dead 2[6]
- Thief II (unofficial NewDark engine update)[7]
- Portal 2[6]
- Alien Swarm[6]
- OpenTTD[8]
- GTAIV's IV-MP[9]
- Mafia II's M2-Multiplayer[10]
- Counter Strike: Global Offensive[6]
- Shadow Warrior
- War Thunder
- Cuisine Royale
- SuperTux
- Sonic Unleashed (PS2/Wii)
- Contagion[6] (PC)
- Thimbleweed Park[11]
- Simutrans[12]
- Vice City Multiplayer (a mod for Grand Theft Auto: Vice City)[13]
- Liberty Unleashed[14]
- Zero no Tsukaima - Muma ga Tsumugu Yokaze no Nocturne (PS2)
- Zero no Tsukaima - Maigo no Period to Ikusen no Symphony (PS2)
- Zero no Tsukaima - Shou-akuma to Harukaze no Concerto (PS2)
- Antinomy of Common Flowers [15]
History
The language was made public in 2003 under the zlib/libpng license.[16] In November 2010, the license was changed to the MIT license to enable the project to be hosted on Google Code.[17][18] It is developed and maintained by Alberto Demichelis.
See also
References
- MirthKit Developer Wiki Archived 2014-02-11 at the Wayback Machine
- Brandon Boyer (21 February 2008). "Gamasutra - GDC 2008 Event Coverage". gamasutra.com. Gamasutra.
- "Exclusive: Behind The Scenes of Final Fantasy's WiiWare Debut". gamasutra.com. Gamasutra. 23 June 2008. Retrieved 22 September 2011.
- "L4D2 Vscripts - Valve Developer Community". developer.valvesoftware.com. Retrieved 2018-07-06.
- "Electric Imp programming guide". electricimp.com.
- "VScript". valvesoftware.com. 2014-08-20. Retrieved 2015-01-17.
- "NewDark 1.25: Squirrel script?". ttlg.com. 2017-03-20. Retrieved 2019-12-25.
- "AI:Main Page - OpenTTD". wiki.openttd.org. Retrieved 2018-07-06.
- "iv-multiplayer.com". www.iv-multiplayer.com. Retrieved 2018-07-06.
- "m2-multiplayer.com". www.m2-multiplayer.com. Retrieved 2018-07-06.
- "Thimbleweed Park Blog- Engine". blog.thimbleweedpark.com. Retrieved 2018-07-06.
- "Simutrans-Squirrel-API: Main Page". dwachs.github.io. Retrieved 2018-07-06.
- "Welcome To VC-MP website!". https://vc-mp.org/. Archived from the original on 2006-04-05. Retrieved 2014-05-04. External link in
|website=
(help) - "Liberty Unleashed". Retrieved 2019-12-04.
- "th155-decomp". Retrieved 2020-10-19.
- "The Squirrel programming language". SourceForge. Retrieved 2018-07-06.
- "Moving to code.google.com and MIT License - The Language - Squirrel - The Programming Language". forum.squirrel-lang.org. Retrieved 2018-07-06.
- "Google Code Archive - Long-term storage for Google Code Project Hosting". code.google.com. Retrieved 2018-07-06.