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Cecil (programming Language)
Cecil is a pure object-oriented programming language that was developed by Craig Chambers at the University of Washington in 1992 to be part of the Vortex project there. Cecil has many similarities to other object-oriented languages, most notably Objective-C, Modula-3, and Self. The main goals of the project were extensibility, orthogonality, efficiency, and ease-of-use. The language supports multiple dispatch and multimethods, dynamic inheritance, and optional static type checking. Unlike most other OOP systems, Cecil allows subtyping and code inheritance to be used separately, allowing run-time or external extension of object classes or instances. Like Objective-C, all object services in Cecil are invoked by message passing, and the language supports run-time class identification. These features allow Cecil to support dynamic, exploratory programming styles. Parameterized types and methods (generics, polymorphism), garbage collection, and delegation are also supported. Cecil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object-oriented Programming
Object-oriented programming (OOP) is a programming paradigm based on the concept of "objects", which can contain data and code. The data is in the form of fields (often known as attributes or ''properties''), and the code is in the form of procedures (often known as ''methods''). A common feature of objects is that procedures (or methods) are attached to them and can access and modify the object's data fields. In this brand of OOP, there is usually a special name such as or used to refer to the current object. In OOP, computer programs are designed by making them out of objects that interact with one another. OOP languages are diverse, but the most popular ones are class-based, meaning that objects are instances of classes, which also determine their types. Many of the most widely used programming languages (such as C++, Java, Python, etc.) are multi-paradigm and they support object-oriented programming to a greater or lesser degree, typically in combination with imper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiple Dispatch
Multiple dispatch or multimethods is a feature of some programming languages in which a function or method can be dynamically dispatched based on the run-time (dynamic) type or, in the more general case, some other attribute of more than one of its arguments. This is a generalization of single-dispatch polymorphism where a function or method call is dynamically dispatched based on the derived type of the object on which the method has been called. Multiple dispatch routes the dynamic dispatch to the implementing function or method using the combined characteristics of one or more arguments. Understanding dispatch Developers of computer software typically organize source code into named blocks variously called subroutines, procedures, subprograms, functions, or methods. The code in the function is executed by ''calling'' it – executing a piece of code that references its ''name''. This transfers control temporarily to the called function; when the function's execution has co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CESIL
CESIL, or Computer Education in Schools Instruction Language, is a programming language designed to introduce pupils in British secondary schools to elementary computer programming. It is a simple language containing a total of fourteen instructions. Background Computer Education in Schools (CES) was a project developed in the late 1960s and early 1970s by International Computers Limited (ICL). CESIL was developed by ICL as part of the CES project, and introduced in 1974. In those days, very few if any schools had computers, so pupils would write programs on coding sheets, which would then be transferred to punched cards or paper tape.''Computer Studies'', page 72 Typically, this would be sent to run on a mainframe computer, with the output from a line printer being returned later. Structure Because CESIL was not designed as an interactive language, there is no facility to input data in real time. Instead, numeric data is included as a separate section at the end of the program. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delegation (programming)
In computing or computer programming, delegation refers generally to one entity passing something to another entity,Barry Wilkinson, ''Grid Computing: Techniques and Applications'' (2009), p. 164, . and narrowly to various specific forms of relationships. These include: * Delegation (object-oriented programming), evaluating a member of one object (the receiver) in the context of another, original object (the sender). ** Delegation pattern, a design pattern implementing this feature. ** Forwarding (object-oriented programming), an often-confused technique where a sending object uses the corresponding member of another object, without the receiving object having any knowledge of the original, sending object. ** Object aggregation or consultation, general term for one object using another. * Delegation (computer security), one user or process allowing another user or process to use their credentials or permissions. * Delegate (CLI), a form of type-safe function pointer used by the Com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garbage Collection (computer Science)
In computer science, garbage collection (GC) is a form of automatic memory management. The ''garbage collector'' attempts to reclaim memory which was allocated by the program, but is no longer referenced; such memory is called '' garbage''. Garbage collection was invented by American computer scientist John McCarthy around 1959 to simplify manual memory management in Lisp. Garbage collection relieves the programmer from doing manual memory management, where the programmer specifies what objects to de-allocate and return to the memory system and when to do so. Other, similar techniques include stack allocation, region inference, and memory ownership, and combinations thereof. Garbage collection may take a significant proportion of a program's total processing time, and affect performance as a result. Resources other than memory, such as network sockets, database handles, windows, file descriptors, and device descriptors, are not typically handled by garbage collection, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Polymorphism
In programming language theory and type theory, polymorphism is the provision of a single interface to entities of different types or the use of a single symbol to represent multiple different types.: "Polymorphic types are types whose operations are applicable to values of more than one type." The concept is borrowed from a principle in biology where an organism or species can have many different forms or stages. The most commonly recognized major classes of polymorphism are: * ''Ad hoc polymorphism'': defines a common interface for an arbitrary set of individually specified types. * ''Parametric polymorphism'': not specifying concrete types and instead use abstract symbols that can substitute for any type. * ''Subtyping'' (also called ''subtype polymorphism'' or ''inclusion polymorphism''): when a name denotes instances of many different classes related by some common superclass. History Interest in polymorphic type systems developed significantly in the 1960s, with practical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Generic Programming
Generic programming is a style of computer programming in which algorithms are written in terms of types ''to-be-specified-later'' that are then ''instantiated'' when needed for specific types provided as parameters. This approach, pioneered by the ML programming language in 1973, permits writing common functions or types that differ only in the set of types on which they operate when used, thus reducing duplication. Such software entities are known as ''generics'' in Ada, C#, Delphi, Eiffel, F#, Java, Nim, Python, Go, Rust, Swift, TypeScript and Visual Basic .NET. They are known as '' parametric polymorphism'' in ML, Scala, Julia, and Haskell (the Haskell community also uses the term "generic" for a related but somewhat different concept); ''templates'' in C++ and D; and ''parameterized types'' in the influential 1994 book ''Design Patterns''. The term "generic programming" was originally coined by David Musser and Alexander Stepanov in a more specific se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exploratory Programming
Exploratory programming, as opposed to implementation (programming), is an important part of the software engineering cycle: when a domain is not very well understood or open-ended, or it's not clear what algorithms and data structures might be needed for an implementation, it's useful to be able to interactively develop and debug a program without having to go through the usual constraints of the edit-compile-run-debug cycle. Languages such as APL, Cecil, C#, Dylan, Factor, Forth, F#, J, Java,through its JShell read-eval-print loop interpreter introduced in version 9 Julia, Lisp, Mathematica, Obliq, Oz, Prolog, Python, REBOL, Perl, R, Ruby, Scala, Self, Smalltalk, Tcl, and JavaScript, often in conjunction with an IDE, provide support for exploratory programming via interactivity, dynamicity, and extensibility. Formal specification versus exploratory programming For some software development projects, it makes sense to do a requirements analysis and a formal specifica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Message Passing
In computer science, message passing is a technique for invoking behavior (i.e., running a program) on a computer. The invoking program sends a message to a process (which may be an actor or object) and relies on that process and its supporting infrastructure to then select and run some appropriate code. Message passing differs from conventional programming where a process, subroutine, or function is directly invoked by name. Message passing is key to some models of concurrency and object-oriented programming. Message passing is ubiquitous in modern computer software. It is used as a way for the objects that make up a program to work with each other and as a means for objects and systems running on different computers (e.g., the Internet) to interact. Message passing may be implemented by various mechanisms, including channels. Overview Message passing is a technique for invoking behavior (i.e., running a program) on a computer. In contrast to the traditional technique of callin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Static Type Checking
In computer programming, a type system is a logical system comprising a set of rules that assigns a property called a type to every "term" (a word, phrase, or other set of symbols). Usually the terms are various constructs of a computer program, such as variables, expressions, functions, or modules. A type system dictates the operations that can be performed on a term. For variables, the type system determines the allowed values of that term. Type systems formalize and enforce the otherwise implicit categories the programmer uses for algebraic data types, data structures, or other components (e.g. "string", "array of float", "function returning boolean"). Type systems are often specified as part of programming languages and built into interpreters and compilers, although the type system of a language can be extended by optional tools that perform added checks using the language's original type syntax and grammar. The main purpose of a type system in a programming language ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inheritance (object-oriented Programming)
In object-oriented programming, inheritance is the mechanism of basing an object or class upon another object ( prototype-based inheritance) or class ( class-based inheritance), retaining similar implementation. Also defined as deriving new classes ( sub classes) from existing ones such as super class or base class and then forming them into a hierarchy of classes. In most class-based object-oriented languages, an object created through inheritance, a "child object", acquires all the properties and behaviors of the "parent object" , with the exception of: constructors, destructor, overloaded operators and friend functions of the base class. Inheritance allows programmers to create classes that are built upon existing classes, to specify a new implementation while maintaining the same behaviors ( realizing an interface), to reuse code and to independently extend original software via public classes and interfaces. The relationships of objects or classes through inheritance give ris ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
