In computing, language primitives are the simplest elements available in a

programming language A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language. The description of a programming ...

. A primitive is the smallest 'unit of processing' available to a programmer of a given machine, or can be an atomic element of an

expression Expression may refer to: Linguistics * Expression (linguistics), a word, phrase, or sentence * Fixed expression, a form of words with a specific meaning * Idiom, a type of fixed expression * Metaphorical expression, a particular word, phrase, o ...

in a language. Primitives are units with a meaning, i.e., a

semantic Semantics (from grc, σημαντικός ''sēmantikós'', "significant") is the study of reference, meaning, or truth. The term can be used to refer to subfields of several distinct disciplines, including philosophy, linguistics and comput ...

value in the language. Thus they are different from tokens in a

parser Parsing, syntax analysis, or syntactic analysis is the process of analyzing a string of symbols, either in natural language, computer languages or data structures, conforming to the rules of a formal grammar. The term ''parsing'' comes from Lati ...

, which are the minimal elements of

syntax In linguistics, syntax () is the study of how words and morphemes combine to form larger units such as phrases and sentences. Central concerns of syntax include word order, grammatical relations, hierarchical sentence structure ( constituency) ...

Machine level primitives

machine instruction In computer programming, machine code is any low-level programming language, consisting of machine language instructions, which are used to control a computer's central processing unit (CPU). Each instruction causes the CPU to perform a very ...

, usually generated by an

assembler Assembler may refer to: Arts and media * Nobukazu Takemura, avant-garde electronic musician, stage name Assembler * Assemblers, a fictional race in the ''Star Wars'' universe * Assemblers, an alternative name of the superhero group Champions of A ...

program, is often considered the smallest unit of processing although this is not always the case. It typically performs what is perceived to be one operation such as copying a

byte The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...

string String or strings may refer to: *String (structure), a long flexible structure made from threads twisted together, which is used to tie, bind, or hang other objects Arts, entertainment, and media Films * ''Strings'' (1991 film), a Canadian anim ...

of bytes from one

computer memory In computing, memory is a device or system that is used to store information for immediate use in a computer or related computer hardware and digital electronic devices. The term ''memory'' is often synonymous with the term ''primary storage ...

location to another or adding one

processor register A processor register is a quickly accessible location available to a computer's processor. Registers usually consist of a small amount of fast storage, although some registers have specific hardware functions, and may be read-only or write-only. ...

to another.

Microcode primitives

Many of today's

computer A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as C ...

s, however, actually embody an even lower unit of processing known as

microcode In processor design, microcode (μcode) is a technique that interposes a layer of computer organization between the central processing unit (CPU) hardware and the programmer-visible instruction set architecture of a computer. Microcode is a laye ...

which interprets the ''machine code'' and it is then that the microcode instructions would be the ''genuine'' primitives. These instructions would typically be available for modification only by the hardware vendor's programmers.

High level language primitives

high-level programming language In computer science, a high-level programming language is a programming language with strong Abstraction (computer science), abstraction from the details of the computer. In contrast to low-level programming languages, it may use natural language ...

(HLL) program is composed of discrete

statements Statement or statements may refer to: Common uses *Statement (computer science), the smallest standalone element of an imperative programming language *Statement (logic), declarative sentence that is either true or false *Statement, a declarative ...

and

primitive data type In computer science, primitive data types are a set of basic data types from which all other data types are constructed. Specifically it often refers to the limited set of data representations in use by a particular processor, which all compiled pr ...

s that may also be ''perceived'' to perform a single operation or represent a single data item, but at a higher semantic level than those provided by the machine. Copying a data item from one location to another may actually involve many

s that, for instance, * calculate the address of both

operand In mathematics, an operand is the object of a mathematical operation, i.e., it is the object or quantity that is operated on. Example The following arithmetic expression shows an example of operators and operands: :3 + 6 = 9 In the above examp ...

s in

memory Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembered, ...

, based on their positions within a

data structure In computer science, a data structure is a data organization, management, and storage format that is usually chosen for efficient access to data. More precisely, a data structure is a collection of data values, the relationships among them, a ...

, * convert from one

data type In computer science and computer programming, a data type (or simply type) is a set of possible values and a set of allowed operations on it. A data type tells the compiler or interpreter how the programmer intends to use the data. Most progra ...

to another before finally * performing the final store operation to the target destination. Some HLL statements, particularly those involving loops, can generate thousands or even millions of primitives in a

low-level programming language A low-level programming language is a programming language that provides little or no abstraction from a computer's instruction set architecture—commands or functions in the language map that are structurally similar to processor's instructions ...

(LLL), which comprise the genuine

instruction path length In computer performance, the instruction path length is the number of machine code instructions required to execute a section of a computer program. The total path length for the entire program could be deemed a measure of the algorithm's performa ...

the processor has to execute at the lowest level. This perception has been referred to as the ''abstraction penalty''.{{Cite book , last1 = Chatzigeorgiou , last2 = Stephanides , editor-last = Blieberger , editor2-last = Strohmeier , contribution = Evaluating Performance and Power Of Object-Oriented Vs. Procedural Programming Languages , title = Proceedings - 7th International Conference on Reliable Software Technologies - Ada-Europe'2002 , year = 2002 , pages = 367 , publisher = Springer , url = https://books.google.com/books?id=QMalP1P2kAMC&q=%22abstraction+penalty%22 , isbn = 978-3-540-43784-0

Interpreted language primitives

interpreted language In computer science, an interpreter is a computer program that directly executes instructions written in a programming or scripting language, without requiring them previously to have been compiled into a machine language program. An interprete ...

statement has similarities to the HLL primitives, but with a further added ''layer''. Before the statement can be executed in a manner very similar to an HLL statement: it must first be processed by an interpreter, a process that may involve many primitives in the target machine language.

Fourth and fifth-generation language primitives

Fourth-generation programming language A fourth-generation programming language (4GL) is any computer programming language that belongs to a class of languages envisioned as an advancement upon third-generation programming languages (3GL). Each of the programming language generations ai ...

s (4GL) and

fifth-generation programming language A fifth-generation programming language (5GL) is any programming language based on problem-solving using constraints given to the program, rather than using an algorithm written by a programmer. Most constraint-based and logic programming languag ...

s (5GL) do not have a simple one-to-many correspondence from high-to-low level primitives. There are some elements of interpreted language primitives embodied in 4GL and 5GL specifications, but the approach to the original problem is less a

procedural language Procedural programming is a programming paradigm, derived from imperative programming, based on the concept of the ''procedure call''. Procedures (a type of routine or subroutine) simply contain a series of computational steps to be carried ...

construct and are more oriented toward

problem solving Problem solving is the process of achieving a goal by overcoming obstacles, a frequent part of most activities. Problems in need of solutions range from simple personal tasks (e.g. how to turn on an appliance) to complex issues in business an ...

and

systems engineering Systems engineering is an interdisciplinary field of engineering and engineering management that focuses on how to design, integrate, and manage complex systems over their enterprise life cycle, life cycles. At its core, systems engineering util ...

References