Interpreter (computing) in the context of Executable

Software consists of computer programs that instruct the execution of a computer. Software also includes design documents and specifications.

The history of software is closely tied to the development of digital computers in the mid-20th century. Early programs were written in the machine language specific to the hardware. The introduction of high-level programming languages in 1958 allowed for more human-readable instructions, making software development easier and more portable across different computer architectures. Software in a programming language is run through a compiler or interpreter to execute on the architecture's hardware. Over time, software has become complex, owing to developments in networking, operating systems, and databases.

A computer program is a sequence or set of instructions in a programming language for a computer to execute. It is one component of software, which also includes documentation and other intangible components.

A computer program in its human-readable form is called source code. Source code needs another computer program to execute because computers can only execute their native machine instructions. Therefore, source code may be translated to machine instructions using a compiler written for the language. (Assembly language programs are translated using an assembler.) The resulting file is called an executable. Alternatively, source code may execute within an interpreter written for the language.

In computing, source code, or simply code or source, is human readable plain text that can eventually result in controlling the behavior of a computer. In order to control a computer, it must be processed by a computer program – either executed directly via an interpreter or translated into a more computer-consumable form such as via a compiler. Sometimes, code is compiled directly to machine code so that it can be run in the native language of the computer without further processing. But, many modern environments involve compiling to an intermediate representation such as bytecode that can either run via an interpreter or be compiled on-demand to machine code via just-in-time compilation.

In computing, execution is the process by which a computer program is processed to perform the actions that it encodes. As the processor follows the program instructions, effects are produced in accordance with the semantics of those instructions. The term run is generally synonymous. The act of starting execution is often called launching or invoking in addition to executing and running.

An execution processor comes in many forms. A machine code program may be executed via the programmable interface of a computer or virtual machine where execution involves repeatedly following a fetch–decode–execute cycle for each program instruction executed by the control unit. Source code may be executed by interpreter software. A program may be executed in a batch process without human interaction or a user may type commands in an interactive session.

The syntax of computer source code is code structured and ordered restricted to computer language rules. Like a natural language, a computer language (i.e. a programming language) defines the syntax that is valid for that language. A syntax error occurs when syntactically invalid source code is processed by an tool such as a compiler or interpreter.

The most commonly used languages are text-based with syntax based on strings. Alternatively, the syntax of a visual programming language is based on relationships between graphical elements.

In computer programming, a comment is text embedded in source code that a translator (compiler or interpreter) ignores. Generally, a comment is an annotation intended to make the code easier for a programmer to understand – often explaining an aspect that is not readily apparent in the program (non-comment) code. For this article, comment refers to the same concept in a programming language, markup language, configuration file and any similar context. Some development tools, other than a source code translator, do parse comments to provide capabilities such as API document generation, static analysis, and version control integration. The syntax of comments varies by programming language yet there are repeating patterns in the syntax among languages as well as similar aspects related to comment content.

The flexibility supported by comments allows for a wide degree of content style variability. To promote uniformity, style conventions are commonly part of a programming style guide. But, best practices are disputed and contradictory.

A translator or programming language processor is a computer program that converts the programming instructions written in human convenient form into machine language codes that the computers understand and process. It is a generic term that can refer to a compiler, assembler, or interpreter—anything that converts code from one computer language into another. These include translations between high-level and human-readable computer languages such as C++ and Java, intermediate-level languages such as Java bytecode, low-level languages such as the assembly language and machine code, and between similar levels of language on different computing platforms, as well as from any of these to any other of these.

Software and hardware represent different levels of abstraction in computing. Software is typically written in high-level programming languages, which are easier for humans to understand and manipulate, while hardware implementations involve low-level descriptions of physical components and their interconnections. Translator computing facilitates the conversion between these abstraction levels. Overall, translator computing plays a crucial role in bridging the gap between software and hardware implementations, enabling developers to leverage the strengths of each platform and optimize performance, power efficiency, and other metrics according to the specific requirements of the application.

Bytecode (also called portable code or p-code) is an intermediate representation form of instruction set designed for efficient execution by a software interpreter. Unlike human-readable source code, bytecodes are compact numeric codes, constants, and references (normally numeric addresses) that encode the result of compiler parsing and performing semantic analysis of things like type, scope, and nesting depths of program objects.

The name bytecode stems from instruction sets that have one-byte opcodes followed by optional parameters. Intermediate representations such as bytecode may be output by programming language implementations to ease interpretation, or it may be used to reduce hardware and operating system dependence by allowing the same code to run cross-platform, on different devices. Bytecode may often be either directly executed on a virtual machine (a p-code machine, i.e., interpreter), or it may be further compiled into machine code for better performance.

In computing, just-in-time (JIT) compilation (also dynamic translation or run-time compilations) is compilation (of computer code) during execution of a program (at run time) rather than before execution. This may consist of source code translation but is more commonly bytecode translation to machine code, which is then executed directly. A system implementing a JIT compiler typically continuously analyses the code being executed and identifies parts of the code where the speedup gained from compilation or recompilation would outweigh the overhead of compiling that code.

JIT compilation is a combination of the two traditional approaches to translation to machine code: ahead-of-time compilation (AOT), and interpretation, which combines some advantages and drawbacks of both. Roughly, JIT compilation combines the speed of compiled code with the flexibility of interpretation, with the overhead of an interpreter and the additional overhead of compiling and linking (not just interpreting). JIT compilation is a form of dynamic compilation, and allows adaptive optimization such as dynamic recompilation and microarchitecture-specific speedups. Interpretation and JIT compilation are particularly suited for dynamic programming languages, as the runtime system can handle late-bound data types and enforce security guarantees.

The first engines for JavaScript were mere interpreters of the source code, but all relevant modern engines use just-in-time compilation for improved performance. JavaScript engines are typically developed by web browser vendors, and every major browser has one. In a browser, the JavaScript engine runs in concert with the rendering engine via the Document Object Model and Web IDL bindings. However, the use of JavaScript engines is not limited to browsers; for example, the V8 engine is a core component of the Node.js runtime system. They are also called ECMAScript engines, after the official name of the specification. With the advent of WebAssembly, some engines can also execute this code in the same sandbox as regular JavaScript code.

A BASIC interpreter is interpreter software that enables users to enter and run programs in the BASIC language and was, for the first part of the microcomputer era, the default application that computers would launch. Users were expected to use the BASIC interpreter to type in programs or to load programs from storage (initially cassette tapes then floppy disks).

BASIC interpreters are of historical importance. Microsoft's first product for sale was a BASIC interpreter (Altair BASIC), which paved the way for the company's success. Before Altair BASIC, microcomputers were sold as kits that needed to be programmed in machine code (for instance, the Apple I). During the Altair period, BASIC interpreters were sold separately, becoming the first software sold to individuals rather than to organizations; Apple BASIC was Apple's first software product. After the MITS Altair 8800, microcomputers were expected to ship bundled with BASIC interpreters of their own (e.g., the Apple II, which had multiple implementations of BASIC). A backlash against the price of Microsoft's Altair BASIC also led to early collaborative software development, for Tiny BASIC implementations in general and Palo Alto Tiny BASIC specifically.

Perl is a high-level, general-purpose, interpreted, dynamic programming language. Though Perl is not officially an acronym, there are various backronyms in use, including "Practical Extraction and Reporting Language".

Perl was developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions. Perl originally was not capitalized and the name was changed to being capitalized by the time Perl 4 was released. The latest release is Perl 5, first released in 1994. From 2000 to October 2019 a sixth version of Perl was in development; the sixth version's name was changed to Raku. Both languages continue to be developed independently by different development teams which liberally borrow ideas from each other.

In computer science and computer programming, a data type (or simply type) is a collection or grouping of data values, usually specified by a set of possible values, a set of allowed operations on these values, and/or a representation of these values as machine types. A data type specification in a program constrains the possible values that an expression, such as a variable or a function call, might take. On literal data, it tells the compiler or interpreter how the programmer intends to use the data. Most programming languages support basic data types of integer numbers (of varying sizes), floating-point numbers (which approximate real numbers), characters and Booleans.