The MOO programming language is a programming language used to support the MOO system. It is a dynamically typed prototype based object oriented system, with syntax derived from the Algol programming language. Computer code (HTML with JavaScript) in a tool that uses syntax highlighting (colors) to help the developer see the purpose of each piece of code. ... Wiktionary has related dictionary definitions, such as: moo Moo or MOO can mean: MOO, a type of MUD text-based virtual reality system MOO programming language Mate of Origin, MOO, a rugby league tournament played annually between Australians and New Zealanders Master of Orion, MOO or MoO, a computer game... One major distinction made in the nature and behaviour of programming languages is that of its typing. ... Prototype-based programming is a style of object-oriented programming in which classes are not present, and inheritance is accomplished by cloning existing objects which serve as prototypes for the new ones. ... Object-oriented programming (OOP) is a computer programming paradigm in which a software system is modeled as a set of objects that interact with each other. ... ALGOL (short for ALGOrithmic Language) is a programming language originally developed in the mid 1950s which became the de facto standard way to report algorithms in print for almost the next 30 years. ...

The language has explicit exception handling control flow, as well as traditional looping constructs. A verb and property hierarchy provides default values to prototype objects, with over-riding values lower in the hierarchy. This hierarchy of objects is maintained through delegation to an object's "parent" property, resulting in a form of single inheritance. Special security-related attributes of objects, verbs, and properties include ownership, and read, write and execute flags. MOO programs are byte-code compiled, with implicit decompilation when editing, providing a canonical form of programs. Exception handling is a programming language construct or computer hardware mechanism designed to handle runtime errors or other problems (exceptions) which occur during the execution of a computer program. ...

MOO programs are orthogonally persistent through periodic checkpoints. Objects are identified by a unique integer identifier. Unused program data is eliminated through automatic garbage collection (implemented by reference counting). However, MOO objects themselves are not garbage collected and are manually deleted by their owners or superusers (aka wizards) through a process called 'recycling.' Persistence is the term used in computer science to describe a capability used by a computer programmer to store data structures in non-volatile storage such as a file system or a relational database. ... In computer science, garbage collection (also known as GC) is a form of automatic memory management. ... In computer science, reference counting is a technique of storing the number of references, pointers, or handles to a resource such as an object or block of memory. ...

MOO is explicitly a multi-user system and programs (verbs) are contributed by any number of connected users. A distinction is made between the 'driver' (runtime) and 'core' (programs written in the MOO language.) The vast majority of the functionality of a running MOO is handled 'in-core.'

The runtime supports multi-tasking using a retribution based time slicing method. Verbs run with exclusive access to the database, so no explicit locking is necessary to maintain synchronization. Simple TCP/IP messaging (telnet compatible) is used to communicate with client sockets, each of which is identified with a 'player' in the Virtual reality representation system. Virtual Reality (VR) is an environment that is simulated by a computer. ...

The language supports weak references to objects by number, and to properties and verbs through strings. Built-in functions to retrieve lists of properties and verbs exist, giving the language runtime facilities for reflection. The server also contains support for wildcard verb matching, so the same code can easily be used to handle multiple commands with similar names and functions. In computer science, reflection (or computational reflection) is the ability of a program to observe and possibly modify its structure and behavior. ...

Available sequence types in MOO are lists and strings. Both support random access, as well as head and tail operations similar to those available in functional programming languages like Lisp. All operations on lists and strings are non-destructive, and all non-object datatypes are immutable. Built-in functions and libraries allow lists to also be used as associative arrays and ordered and unordered sets. In computer science, a datatype or data type (often simply a type) is a name or label for a set of values and some operations which one can perform on that set of values. ... Functional programming is a programming paradigm that treats computation as the evaluation of mathematical functions. ... Lisp is a family of computer programming languages with a long history and a distinctive fully-parenthesized syntax. ...

See also

• MOO (game system)
• CoolMUD (descendant of MOO, also written by Stephen White)

Wiktionary has related dictionary definitions, such as: moo Moo or MOO can mean: MOO, a type of MUD text-based virtual reality system MOO programming language Mate of Origin, MOO, a rugby league tournament played annually between Australians and New Zealanders Master of Orion, MOO or MoO, a computer game... CoolMUD is a type of MUD, and a descendant of MOO. It is a text-based online virtual reality system to which multiple users are connected at the same time. ...

External links

• The LambdaMOO Programmer's Manual is the definitive reference for the MOO programming language.