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Linden Scripting Language, or LSL, is the programming language used by residents of Second Life (SL), a virtual world by Linden Lab〔(Getting started with LSL - Second Life Wiki ). Wiki.secondlife.com (2013-07-01). Retrieved on 2013-09-21.〕 and similar virtual worlds. LSL has a syntax similar to C and allows objects to control the behavior of in-world objects of Second Life from the Internet via email, XML-RPC, and most recently, HTTP requests. ==LSL design== Linden Scripting Language is a state-event driven scripting language, in the sense of a finite state machine.〔(Category:LSL Events - Second Life Wiki ). Wiki.secondlife.com (2011-08-08). Retrieved on 2013-09-21.〕 A script consists of variables, function definitions, and one or more named states. Each state contains a description of how to react to events that occur while the program is within that state. The system sends to the script, such as timers, movement, chat (from other agents), email, and collisions (with objects in the virtual world). Scripts can change most aspects of the state of the object and communicate with other objects and agents. As soon as a script is added to an object, and turned on, it begins to execute. A script is tightly bound to the concept of virtual-world ''objects'' (in the 3D modeling sense rather than in the object-oriented sense) called ''primitives''. An object in Second Life represents something like a chair or a wall, or possibly something invisible. Multiple scripts may be placed inside an object, where they all execute simultaneously. There are over 300 library functions available.〔(Category:LSL Functions - Second Life Wiki ). Wiki.secondlife.com (2012-09-08). Retrieved on 2013-09-21.〕 Users can also define additional functions. LSL is a strongly typed language〔(Category:LSL Types - Second Life Wiki ). Wiki.secondlife.com (2012-04-27). Retrieved on 2013-09-21.〕 that is compiled to bytecode before runtime execution in a virtual machine (VM) on one of Linden Lab's servers. LSL's native data structures includes integers,〔(Category:LSL Integer - Second Life Wiki ). Wiki.secondlife.com (2012-12-22). Retrieved on 2013-09-21.〕 floating point numbers,〔https://wiki.secondlife.com/wiki/Category:LSL_Float〕 strings,〔(Category:LSL String - Second Life Wiki ). Wiki.secondlife.com (2013-05-19). Retrieved on 2013-09-21.〕 keys(UUID),〔(Category:LSL Key - Second Life Wiki ). Wiki.secondlife.com (2013-09-11). Retrieved on 2013-09-21.〕 vectors (used for 3D coordinates and RGB color expression),〔(Category:LSL Vector - Second Life Wiki ). Wiki.secondlife.com (2011-10-05). Retrieved on 2013-09-21.〕 and rotations (quaternions).〔(Category:LSL Rotation - Second Life Wiki ). Wiki.secondlife.com (2008-10-24). Retrieved on 2013-09-21.〕 There are also heterogeneous lists. There are no arrays; multiple list functions are used to adapt programs requiring array structures.〔(Category:LSL List - Second Life Wiki ). Wiki.secondlife.com. Retrieved on 2013-09-21.〕 There is no built-in persistent data storage, such as a file or database (though users have found various workarounds for this like storing data in various data fields of the items containing scripts). On the other hand, scripts continue to run even when a user is not logged in, and if an object is saved (taken into inventory), and then re-introduced into the World later, it still maintains its previous state. In addition, the mechanisms for communicating via HTTP can be used to store a state externally. Some functions in LSL have built-in delays, which range from a 0.1-second delay when (for example) requesting string data from a notecard;〔https://wiki.secondlife.com/wiki/Category:LSL_Notecard An in-world data storage medium mainly used for text.〕 to a 20-second script pause after sending an e-mail message. The delays help prevent developers from writing LSL scripts that could overtax system resources. Memory available to LSL scripts (when compiled as mono) is capped at about 64 KiB, which places a practical limit on how much a single script can do, however the ability to use multiple scripts and to call scripts from another script allows the user to pragmatically work around this 64 KiB cap. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Linden Scripting Language」の詳細全文を読む スポンサード リンク
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