Compiler A diagram of the operation of a typical multi-language, multi-target compiler A compiler is a computer program (or set of programs) that transforms source code written in a programming language (the source language) into another computer language (the target language, often having a binary form known as object code).[1] The most common reason for wanting to transform source code is to create an executable program. Program faults caused by incorrect compiler behavior can be very difficult to track down and work around; therefore, compiler implementors invest significant effort to ensure compiler correctness. The term compiler-compiler is sometimes used to refer to a parser generator, a tool often used to help create the lexer and parser. History[edit] Software for early computers was primarily written in assembly language. Towards the end of the 1950s, machine-independent programming languages were first proposed. Compilers in education[edit] Compilation[edit] Structure of a compiler[edit]
Interpreter (computing) parse the source code and perform its behavior directlytranslate source code into some efficient intermediate representation and immediately execute thisexplicitly execute stored precompiled code[1] made by a compiler which is part of the interpreter system While interpretation and compilation are the two main means by which programming languages are implemented, they are not mutually exclusive, as most interpreting systems also perform some translation work, just like compilers. The terms "interpreted language" or "compiled language" signify that the canonical implementation of that language is an interpreter or a compiler, respectively. A high level language is ideally an abstraction independent of particular implementations. An illustration of the linking process. At the stage of compilation, in fact compilers act as interpreters and patch together such binary executables from an object code library defining which binary code sequence is named which command name.
Perl Though Perl is not officially an acronym,[5] there are various backronyms in use, such as: Practical Extraction and Reporting Language.[6] Perl was originally developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier.[7] Since then, it has undergone many changes and revisions. The latest major stable revision of Perl 5 is 5.18, released in May 2013. Perl 6, which began as a redesign of Perl 5 in 2000, eventually evolved into a separate language. Both languages continue to be developed independently by different development teams and liberally borrow ideas from one another. History[edit] Early versions[edit] Wall began work on Perl in 1987, while working as a programmer at Unisys,[9] and released version 1.0 to the comp.sources.misc newsgroup on December 18, 1987.[14] The language expanded rapidly over the next few years. Perl 2, released in 1988, featured a better regular expression engine. Early Perl 5[edit] 2000–present[edit] Name[edit]
List of programming languages The aim of this list of programming languages is to include all notable programming languages in existence, both those in current use and historical ones, in alphabetical order, except for dialects of BASIC and esoteric programming languages. Note: Dialects of BASIC have been moved to the separate List of BASIC dialects. Note: This page does not list esoteric programming languages. A[edit] B[edit] C[edit] D[edit] E[edit] F[edit] G[edit] H[edit] I[edit] J[edit] K[edit] L[edit] M[edit] N[edit] O[edit] P[edit] Q[edit] R[edit] S[edit] T[edit] U[edit] V[edit] W[edit] X[edit] Y[edit] Z[edit] See also[edit]
C (programming language) C is one of the most widely used programming languages of all time,[8][9] and C compilers are available for the majority of available computer architectures and operating systems. C is an imperative (procedural) language. It was designed to be compiled using a relatively straightforward compiler, to provide low-level access to memory, to provide language constructs that map efficiently to machine instructions, and to require minimal run-time support. C was therefore useful for many applications that had formerly been coded in assembly language, such as in system programming. Despite its low-level capabilities, the language was designed to encourage cross-platform programming. A standards-compliant and portably written C program can be compiled for a very wide variety of computer platforms and operating systems with few changes to its source code. The C language also exhibits the following characteristics: The cover of the book, The C Programming Language For example:
Generational list of programming languages Here, a genealogy of programming languages is shown. Languages are categorized under the ancestor language with the strongest influence. Of course, any such categorization has a large arbitrary element, since programming languages often incorporate major ideas from multiple sources. ALGOL based[edit] APL based[edit] BASIC based[edit] Batch languages[edit] C based[edit] COBOL based[edit] COMIT based[edit] DCL based[edit] DCLWindows PowerShell (also under C#, ksh and Perl) ed based[edit] Eiffel based[edit] Forth based[edit] Fortran based[edit] FP based[edit] HyperTalk based[edit] Java based[edit] JOSS based[edit] Lisp based[edit] ML based[edit] PL/I based[edit] Prolog based[edit] SASL Based[edit] SETL based[edit] sh based[edit] Sh Simula based[edit] Tcl based[edit] Others[edit] External links[edit] Diagram & history of programming languages
Algorithm Flow chart of an algorithm (Euclid's algorithm) for calculating the greatest common divisor (g.c.d.) of two numbers a and b in locations named A and B. The algorithm proceeds by successive subtractions in two loops: IF the test B ≥ A yields "yes" (or true) (more accurately the numberb in location B is greater than or equal to the numbera in location A) THEN, the algorithm specifies B ← B − A (meaning the number b − a replaces the old b). Similarly, IF A > B, THEN A ← A − B. The process terminates when (the contents of) B is 0, yielding the g.c.d. in A. In mathematics and computer science, an algorithm ( i/ˈælɡərɪðəm/ AL-gə-ri-dhəm) is a step-by-step procedure for calculations. Informal definition[edit] While there is no generally accepted formal definition of "algorithm," an informal definition could be "a set of rules that precisely defines a sequence of operations Boolos & Jeffrey (1974, 1999) offer an informal meaning of the word in the following quotation: Formalization[edit]
Flowchart A simple flowchart representing a process for dealing with a non-functioning lamp. A flowchart is a type of diagram that represents an algorithm, workflow or process, showing the steps as boxes of various kinds, and their order by connecting them with arrows. This diagrammatic representation illustrates a solution to a given problem. Flowcharts are used in analyzing, designing, documenting or managing a process or program in various fields.[1] Overview[edit] Flowcharts are used in designing and documenting complex processes or programs. a processing step, usually called activity, and denoted as a rectangular boxa decision, usually denoted as a diamond. A flowchart is described as "cross-functional" when the page is divided into different swimlanes describing the control of different organizational units. Flowcharts depict certain aspects of processes and they are usually complemented by other types of diagram. History[edit] Flowchart building blocks[edit] Examples[edit] Symbols[edit] Arrows
Pseudocode Pseudocode is an informal high-level description of the operating principle of a computer program or other algorithm. It uses the structural conventions of a programming language, but is intended for human reading rather than machine reading. Pseudocode typically omits details that are not essential for human understanding of the algorithm, such as variable declarations, system-specific code and some subroutines. Application[edit] Textbooks and scientific publications related to computer science and numerical computation often use pseudocode in description of algorithms, so that all programmers can understand them, even if they do not all know the same programming languages. A programmer who needs to implement a specific algorithm, especially an unfamiliar one, will often start with a pseudocode description, and then "translate" that description into the target programming language and modify it to interact correctly with the rest of the program. Syntax[edit] Return See also[edit]
Semantics The formal study of semantics intersects with many other fields of inquiry, including lexicology, syntax, pragmatics, etymology and others. Independently, semantics is also a well-defined field in its own right, often with synthetic properties.[4] In the philosophy of language, semantics and reference are closely connected. Further related fields include philology, communication, and semiotics. The formal study of semantics can therefore be manifold and complex. Semantics contrasts with syntax, the study of the combinatorics of units of a language (without reference to their meaning), and pragmatics, the study of the relationships between the symbols of a language, their meaning, and the users of the language.[5] Semantics as a field of study also has significant ties to various representational theories of meaning including truth theories of meaning, coherence theories of meaning, and correspondence theories of meaning. Linguistics[edit] Montague grammar[edit] Prototype theory[edit]
Logic programming Logic programming is a programming paradigm based on formal logic. Programs written in a logical programming language are sets of logical sentences, expressing facts and rules about some problem domain. Together with an inference algorithm, they form a program. Major logic programming languages include Prolog and Datalog. A form of logical sentences commonly found in logic programming, but not exclusively, is the Horn clause. p(X, Y) if q(X) and r(Y) Logical sentences can be understood purely declaratively. The programmer can use the declarative reading of logic programs to verify their correctness. History[edit] The use of mathematical logic to represent and execute computer programs is also a feature of the lambda calculus, developed by Alonzo Church in the 1930s. In 1997, the Association of Logic Programming bestowed to fifteen recognized researchers in logic programming the title Founders of Logic Programming to recognize them as pioneers in the field:[1] Prolog[edit] H :- B1, …, Bn.