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GNU Guile

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GNU Ubiquitous Intelligent Language for Extensions ( GNU Guile ) is the preferred extension language system for the GNU Project and features an implementation of the programming language Scheme . Its first version was released in 1993. In addition to large parts of Scheme standards, Guile Scheme includes modularized extensions for many different programming tasks.

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82-650: For extending programs, Guile offers libguile which allows the language to be embedded in other programs, and integrated closely through the C language application programming interface (API); similarly, new data types and subroutines defined through the C API can be made available as extensions to Guile. Guile is used in many programs under the GNU project umbrella ( GDB , Make , Guix , GNU TeXmacs , GnuCash , LilyPond , Lepton-EDA ...) but it also sees use outside of that, for example in Google's schism . Guile Scheme

164-531: A dialect of Scheme essentially differing only in its C-like syntax, a translation of Emacs Lisp , a Tcl converter motivated by tkWWW , and something roughly resembling the language Logo . With version 2.0, the project successfully transitioned to a compiler tower approach, allowing the definition of compilers from one language to another, typically from a higher-level one to a lower-level intermediate representation , and eventually virtual machine bytecode or native machine code . On 16 Mar 2017, Guile 2.2.0

246-450: A carrier group is used for crossposting to aid distribution. This is typically only useful for groups that have been removed or newer alt.* groups. Crossposts between hierarchies, outside of the Big 8 and alt.* hierarchies, are prone to failure. Newsgroups are often arranged into hierarchies , theoretically making it simpler to find related groups. The term top-level hierarchy refers to

328-452: A certain platform or with a particular compiler, due, for example, to the use of non-standard libraries, such as GUI libraries, or to a reliance on compiler- or platform-specific attributes such as the exact size of data types and byte endianness . In cases where code must be compilable by either standard-conforming or K&R C-based compilers, the __STDC__ macro can be used to split the code into Standard and K&R sections to prevent

410-511: A criticism to the comp.lang.tcl newsgroup, which initiated a flamewar known as the "Tcl War". Since the public announcement of the Guile project coincided with the Tcl debate, it has become a common misconception that Guile began as a reaction to this. After the initial release of Guile, development languished for many years, but 2009–2010 saw major improvements, and Guile 2.0 was released in 2011 with

492-430: A file uploaded once will be spread to many other servers and can then be downloaded by an unlimited number of users. More useful is that users download from a local news server, rather than from a more distant machine with perhaps limited connectivity, as may be the case with peer-to-peer technology. In fact, this is another benefit of newsgroups: it is usually not expected that users share. If every user makes uploads then

574-409: A long while, it was impossible to send binary data as such. As workarounds, codecs such as Uuencode and later Base64 and yEnc were developed which encoded the binary data from the files to be transmitted (e.g. sound or video files) to text characters which would survive transmission over Usenet. At the receiver's end, the data needed to be decoded by the user's news client . Additionally, there

656-476: A naming conflict with another programming language, he solicited suggestions for a new name. From several contributions in several Usenet newsgroups , Lord controversially chose Guile from a suggestion by Lee Thomas. During the development of Guile (then GEL) and before its public release, the extension language Tcl was gaining popularity and being pushed as a universal extension language. Stallman saw Tcl as being underpowered as an extension language, and posted

738-541: A new compiler infrastructure, a virtual machine implementation, a switch to the Boehm–Demers–Weiser garbage collector , many improvements to the Guile Scheme language, and other major changes. One of the goals of Guile is to allow other languages to be used alongside Scheme, such that Guile would effectively be a language-neutral runtime environment. Various attempts at this have been made in past versions:

820-444: A news server maintains agreements with other nearby news servers to synchronize regularly. In this way news servers form a redundant network. When a user posts to one news server, the post is stored locally. That server then shares posts with the servers that are connected to it for those newsgroups they both carry. Those servers do likewise, propagating the posts through the network. For newsgroups that are not widely carried, sometimes

902-463: A newsgroup is called a "post". Some newsgroups allow posts on a wide variety of themes, regarding anything a member chooses to discuss as on-topic , while others keep more strictly to their particular subject, frowning on off-topic posts. The news admin (the administrator of a news server ) decides how long posts are kept on their server before being expired (deleted), which is called retention . Different servers will have different retention times for

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984-514: A newsgroup, and anybody can remove it, but most news administrators will ignore these requests unless a local user requests the group by name. There are a number of newsgroup hierarchies outside of the Big 8 (and alt.*) that can be found on many news servers. These include non-English language groups, groups managed by companies or organizations about their products, geographic/local hierarchies, and even non-internet network boards routed into NNTP. Examples include (alphabetically): Additionally, there

1066-497: A practice called Usenet backup , or uBackup. While commercial providers offer easier-to-use online backup services , storing data on Usenet is free of charge (although access to Usenet itself may not be). A user must manually select, prepare and upload the data . Because anyone can download the backup files, the data is typically encrypted . After the files are uploaded, the uploader has no control over them; they are automatically distributed to all Usenet providers that subscribe to

1148-471: A requirement of the Scheme standard, Guile copies the execution stack into the heap and back. Its manual suggests using delimited continuations instead, because they have a more efficient implementation. Because foreign code may have pointers to Scheme objects, Guile uses the conservative Boehm–Demers–Weiser (BDW) garbage collector . The Guile manual gives details of the inception and early history of

1230-590: A semicolon; as a side effect of the evaluation, functions may be called and variables assigned new values. To modify the normal sequential execution of statements, C provides several control-flow statements identified by reserved keywords. Structured programming is supported by if ... [ else ] conditional execution and by do ... while , while , and for iterative execution (looping). The for statement has separate initialization, testing, and reinitialization expressions, any or all of which can be omitted. break and continue can be used within

1312-423: A warning message if a local function was called with the wrong number of arguments, or if different calls to an external function used different numbers or types of arguments. Separate tools such as Unix's lint utility were developed that (among other things) could check for consistency of function use across multiple source files. In the years following the publication of K&R C, several features were added to

1394-612: A wide variety of mainframe computers , minicomputers , and microcomputers , including the IBM PC , as its popularity began to increase significantly. In 1983 the American National Standards Institute (ANSI) formed a committee, X3J11, to establish a standard specification of C. X3J11 based the C standard on the Unix implementation; however, the non-portable portion of the Unix C library was handed off to

1476-439: Is completion rates and the other is retention rates . The business of premium news servers is generated primarily on their ability to offer superior completion and retention rates, as well as their ability to offer very fast connections to users. Completion rates are significant when users wish to download large files that are split into pieces; if any one piece is missing, it is impossible to successfully download and reassemble

1558-471: Is a general-purpose , high-level programming language whose flexibility allows expressing concepts in fewer lines of code than would be possible in languages such as C . For example, its hygienic macro system allows adding domain specific syntax-elements without modifying Guile. Guile implements the Scheme standard R5RS, most of R6RS and R7RS, several Scheme Requests for Implementation (SRFI), and many extensions of its own. The core idea of Guile Scheme

1640-576: Is a repository usually within the Usenet system, for messages posted from users in different locations using the Internet . They are discussion groups and are not devoted to publishing news . Newsgroups are technically distinct from, but functionally similar to, discussion forums on the World Wide Web . Newsreader software is used to read the content of newsgroups. Before the adoption of

1722-498: Is an imperative , procedural language in the ALGOL tradition. It has a static type system . In C, all executable code is contained within subroutines (also called "functions", though not in the sense of functional programming ). Function parameters are passed by value, although arrays are passed as pointers , i.e. the address of the first item in the array. Pass-by-reference is simulated in C by explicitly passing pointers to

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1804-505: Is an accepted version of this page C ( pronounced / ˈ s iː / – like the letter c ) is a general-purpose programming language . It was created in the 1970s by Dennis Ritchie and remains very widely used and influential. By design, C's features cleanly reflect the capabilities of the targeted CPUs. It has found lasting use in operating systems code (especially in kernels ), device drivers , and protocol stacks , but its use in application software has been decreasing. C

1886-456: Is an informal name for the current major C language standard revision. It was informally known as "C2X" through most of its development. C23 was published in October 2024 as ISO/IEC 9899:2024. The standard macro __STDC_VERSION__ is defined as 202311L to indicate that C23 support is available. C2Y is an informal name for the next major C language standard revision, after C23 (C2X), that

1968-554: Is around twice as good on the whole, while some individual benchmarks are up to 32 times as fast. It also featured support for interleaved definitions and expressions in lexical contexts, native support for structured exceptions, better support for the R6RS and R7RS Scheme standards and many optimizations. There have been several past unfinished attempts to replace or supplement the Emacs Lisp extension language with Guile, parallel to

2050-456: Is commonly used on computer architectures that range from the largest supercomputers to the smallest microcontrollers and embedded systems . A successor to the programming language B , C was originally developed at Bell Labs by Ritchie between 1972 and 1973 to construct utilities running on Unix . It was applied to re-implementing the kernel of the Unix operating system. During the 1980s, C gradually gained popularity. It has become one of

2132-504: Is defined as 201112L to indicate that C11 support is available. C17 is an informal name for ISO/IEC 9899:2018, a standard for the C programming language published in June 2018. It introduces no new language features, only technical corrections, and clarifications to defects in C11. The standard macro __STDC_VERSION__ is defined as 201710L to indicate that C17 support is available. C23

2214-524: Is for the most part backward compatible with C90, but is stricter in some ways; in particular, a declaration that lacks a type specifier no longer has int implicitly assumed. A standard macro __STDC_VERSION__ is defined with value 199901L to indicate that C99 support is available. GCC , Solaris Studio , and other C compilers now support many or all of the new features of C99. The C compiler in Microsoft Visual C++ , however, implements

2296-469: Is hoped to be released later in the 2020s decade, hence the '2' in "C2Y". An early working draft of C2Y was released in February 2024 as N3220 by the working group ISO/IEC JTC1/SC22 /WG14. Historically, embedded C programming requires non-standard extensions to the C language to support exotic features such as fixed-point arithmetic , multiple distinct memory banks , and basic I/O operations. In 2008,

2378-416: Is no technical difference between the two, but the naming differentiation allows users and servers with limited facilities to minimize network bandwidth usage. Generally, Usenet conventions and rules are enacted with the primary intention of minimizing the overall amount of network traffic and resource usage. Typically, the newsgroup is focused on a particular topic of interest. A message sent for publication on

2460-622: Is now also referred to as C78 . The second edition of the book covers the later ANSI C standard, described below. K&R introduced several language features: Even after the publication of the 1989 ANSI standard, for many years K&R C was still considered the " lowest common denominator " to which C programmers restricted themselves when maximum portability was desired, since many older compilers were still in use, and because carefully written K&R C code can be legal Standard C as well. In early versions of C, only functions that return types other than int must be declared if used before

2542-420: Is sometimes called C90. Therefore, the terms "C89" and "C90" refer to the same programming language. ANSI, like other national standards bodies, no longer develops the C standard independently, but defers to the international C standard, maintained by the working group ISO/IEC JTC1/SC22 /WG14. National adoption of an update to the international standard typically occurs within a year of ISO publication. One of

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2624-452: Is that "the developer implements critical algorithms and data structures in C or C++ and exports the functions and types for use by interpreted code. The application becomes a library of primitives orchestrated by the interpreter, combining the efficiency of compiled code with the flexibility of interpretation." Thus Guile Scheme (and other languages implemented by Guile) can be extended with new data types and subroutines implemented through

2706-487: Is then discussed in news.groups.proposals . Once the proposal has been formalized with a name, description, charter, the Big-8 Management Board will vote on whether to create the group. If the proposal is approved by the Big-8 Management Board , the group is created. Groups are removed in a similar manner. Creating a new group in the alt.* hierarchy is not subject to the same rules; anybody can create

2788-569: The Great Renaming of 1986–1987, before which all of these newsgroups were in the net.* hierarchy. At that time there was a great controversy over what newsgroups should be allowed. Among those that the Usenet cabal (who effectively ran the Big 7 at the time) did not allow were those concerning recipes , recreational drug use , and sex . This situation resulted in the creation of an alt.* (short for "alternative") Usenet hierarchy, under which these groups would be allowed. Over time,

2870-597: The IEEE working group 1003 to become the basis for the 1988 POSIX standard. In 1989, the C standard was ratified as ANSI X3.159-1989 "Programming Language C". This version of the language is often referred to as ANSI C , Standard C, or sometimes C89. In 1990 the ANSI C standard (with formatting changes) was adopted by the International Organization for Standardization (ISO) as ISO/IEC 9899:1990, which

2952-590: The International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). C is an imperative procedural language, supporting structured programming , lexical variable scope , and recursion , with a static type system . It was designed to be compiled to provide low-level access to memory and language constructs that map efficiently to machine instructions , all with minimal runtime support . Despite its low-level capabilities,

3034-566: The World Wide Web , Usenet newsgroups were among the most popular Internet services. Communication is facilitated by the Network News Transfer Protocol (NNTP) which allows connection to Usenet servers and data transfer over the internet. Similar to another early (yet still used) protocol SMTP which is used for email messages, NNTP allows both server-server and client-server communication. This means that newsgroups can be replicated from server to server which gives

3116-471: The C API. The standard distribution offers modules for Portable Operating System Interface ( POSIX ) system calls, scheduling , a foreign function interface , S-expression based XML processing through SXML , SXPath, and SXSLT, HTTP and other World Wide Web APIs, delimited continuations , array programming , and other functionality. Guile programs can use facilities from SLIB , the portable Scheme library. When using continuations with call/cc ,

3198-483: The C Standards Committee published a technical report extending the C language to address these issues by providing a common standard for all implementations to adhere to. It includes a number of features not available in normal C, such as fixed-point arithmetic, named address spaces, and basic I/O hardware addressing. C has a formal grammar specified by the C standard. Line endings are generally not significant in C; however, line boundaries do have significance during

3280-597: The C89 standard and those parts of C99 that are required for compatibility with C++11 . In addition, the C99 standard requires support for identifiers using Unicode in the form of escaped characters (e.g. \u0040 or \U0001f431 ) and suggests support for raw Unicode names. Work began in 2007 on another revision of the C standard, informally called "C1X" until its official publication of ISO/IEC 9899:2011 on December 8, 2011. The C standards committee adopted guidelines to limit

3362-522: The Usenet network the ability to maintain a level of robust data persistence as a result of built-in data redundancy. However, most users will access using only the client-server commands of NNTP and in almost all cases will use a GUI for browsing as opposed to command line based client-server communication specified in the NNTP protocol. Newsgroups generally come in either of two types, binary or text. There

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3444-438: The adoption of new features that had not been tested by existing implementations. The C11 standard adds numerous new features to C and the library, including type generic macros, anonymous structures, improved Unicode support, atomic operations, multi-threading, and bounds-checked functions. It also makes some portions of the existing C99 library optional, and improves compatibility with C++. The standard macro __STDC_VERSION__

3526-428: The aims of the C standardization process was to produce a superset of K&R C, incorporating many of the subsequently introduced unofficial features. The standards committee also included several additional features such as function prototypes (borrowed from C++), void pointers, support for international character sets and locales , and preprocessor enhancements. Although the syntax for parameter declarations

3608-416: The basis for several implementations of C on new platforms. In 1978 Brian Kernighan and Dennis Ritchie published the first edition of The C Programming Language . Known as K&R from the initials of its authors, the book served for many years as an informal specification of the language. The version of C that it describes is commonly referred to as " K&R C ". As this was released in 1978, it

3690-417: The bounds of the network uses the Network News Transfer Protocol (NNTP) (Internet standard RFC 3977 of 2006, updating RFC 977 of 1986). Newsgroup servers are hosted by various organizations and institutions. Most Internet service providers host their own news servers , or rent access to one, for their subscribers. There are also a number of companies who sell access to premium news servers. Every host of

3772-415: The creation of user-space concurrency facilities that multiplex millions of concurrent lightweight "fibers" and provided a complete Emacs-compatible Elisp implementation, implementing all of Elisp's features and quirks in the same way as Emacs. On 16 January 2020, Guile 3.0.0 was released with just-in-time ( JIT ) native code generation for much greater performance. Compared to 2.2, microbenchmark performance

3854-433: The desired file. To work around the problem, a redundancy scheme known as Parchive (PAR) is commonly used. Many major news servers have a retention time of more than seven years. A number of websites exist to keep an index of files posted to binary newsgroups. Partly because of such long retention times, as well as growing uploading and downloading speeds, Usenet is also used by individuals to store backup data in

3936-708: The efforts of supporting other languages in Guile. With version 2.0 of Guile, a new attempt at implementing Elisp on the Guile compiler tower and replacing Emacs's Elisp implementation with that of libguile has begun and made significant progress through Google Summer of Code projects. A Guile-based Emacs could offer better execution performance for Emacs Lisp, support new Emacs Lisp language features more easily, make Guile libraries written in other programming languages available to Emacs Lisp code, and allow writing Emacs extensions in other programming languages supported by Guile, all while remaining fully backward compatible with existing Emacs Lisp code bases. As of October 2014,

4018-481: The end of each expression statement, and the entry to and return from each function call. Sequence points also occur during evaluation of expressions containing certain operators ( && , || , ?: and the comma operator ). This permits a high degree of object code optimization by the compiler, but requires C programmers to take more care to obtain reliable results than is needed for other programming languages. Usenet newsgroup A Usenet newsgroup

4100-650: The features of the more-powerful PDP-11. A significant addition was a character data type. He called this New B (NB). Thompson started to use NB to write the Unix kernel, and his requirements shaped the direction of the language development. Through to 1972, richer types were added to the NB language: NB had arrays of int and char . Pointers, the ability to generate pointers to other types, arrays of all types, and types to be returned from functions were all also added. Arrays within expressions became pointers. A new compiler

4182-477: The function definition; functions used without prior declaration were presumed to return type int . For example: The int type specifiers which are commented out could be omitted in K&;R C, but are required in later standards. Since K&R function declarations did not include any information about function arguments, function parameter type checks were not performed, although some compilers would issue

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4264-409: The hierarchy defined by the prefix before the first dot. The most commonly known hierarchies are the Usenet hierarchies . So for instance newsgroup rec.arts.sf.starwars.games would be in the rec.* top-level Usenet hierarchy, where the asterisk (*) is defined as a wildcard character . There were seven original major hierarchies of Usenet newsgroups, known as the "Big 7": These were all created in

4346-487: The implementation had reached a stage where Guile Emacs is able to reliably run most Emacs Lisp code. Remaining problems or possible problems involve the different internal representation of Emacs Lisp strings from Scheme strings, the difference between how Emacs Lisp and Scheme treat the Boolean false and empty list objects, Emacs Lisp macros not integrating with Scheme, Emacs Lisp not having been designed for concurrency, and

4428-452: The language was designed to encourage cross-platform programming. A standards -compliant C program written with portability in mind can be compiled for a wide variety of computer platforms and operating systems with few changes to its source code. Since 2000, C has consistently ranked among the top four languages in the TIOBE index , a measure of the popularity of programming languages. C

4510-438: The language, supported by compilers from AT&T (in particular PCC ) and some other vendors. These included: The large number of extensions and lack of agreement on a standard library , together with the language popularity and the fact that not even the Unix compilers precisely implemented the K&R specification, led to the necessity of standardization. During the late 1970s and 1980s, versions of C were implemented for

4592-562: The language. A brief summary follows: After the success of Emacs in the free software community, as a highly extensible and customizable application via its extension (and partly implementation) language Emacs Lisp , the community began to consider how this design strategy could apply to the rest of the GNU system. Tom Lord initially began work on an embeddable language runtime named the GNU Extension Language (GEL), which

4674-454: The laxness of rules on newsgroup creation in alt.* compared to the Big 7 meant that many new topics could, given time, gain enough popularity to get a Big 7 newsgroup. There was a rapid growth of alt.* as a result, and the trend continues to this day. Because of the anarchistic nature with which the groups sprang up, some jokingly referred to ALT standing for " A narchists , L unatics and T errorists " (a backronym ). In 1995, humanities.*

4756-413: The loop. Break is used to leave the innermost enclosing loop statement and continue is used to skip to its reinitialisation. There is also a non-structured goto statement which branches directly to the designated label within the function. switch selects a case to be executed based on the value of an integer expression. Different from many other languages, control-flow will fall through to

4838-425: The most widely used programming languages, with C compilers available for practically all modern computer architectures and operating systems. The book The C Programming Language , co-authored by the original language designer, served for many years as the de facto standard for the language. C has been standardized since 1989 by the American National Standards Institute (ANSI) and, subsequently, jointly by

4920-477: The newsgroup they are uploaded to, so there will be copies of them spread all around the world. Most Newsgroups are not moderated. A moderated newsgroup has one or more individuals who must approve posts before they are published. A separate address is used to submit posts and the moderators then propagate those they approve of. The first moderated newsgroups appeared in 1984 under mod.* according to RFC 2235 , "Hobbes' Internet Timeline". Transmission within and at

5002-411: The next case unless terminated by a break . Expressions can use a variety of built-in operators and may contain function calls. The order in which arguments to functions and operands to most operators are evaluated is unspecified. The evaluations may even be interleaved. However, all side effects (including storage to variables) will occur before the next " sequence point "; sequence points include

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5084-419: The operating system to a PDP-11 . The original PDP-11 version of Unix was also developed in assembly language. Thompson wanted a programming language for developing utilities for the new platform. He first tried writing a Fortran compiler, but he soon gave up the idea and instead created a cut-down version of the recently developed systems programming language called BCPL . The official description of BCPL

5166-599: The platform. The number of newsgroups grew from more than 100 as of 1983 to more than 110,000, but only 20,000 or so of those are active. Newsgroups vary in popularity; some newsgroups receive fewer than a dozen posts per year while the most popular can get several thousand in under an hour. While newsgroups were not created with the intention of distributing files such as pictures, sound and video, they have proven to be quite effective for this. As of 2022, some remain popular as an alternative to BitTorrent to share and download files. Because newsgroups are widely distributed,

5248-475: The portability of Guile to platforms supported by Emacs. Other concerns raised by the Emacs community include the relative sizes of the Emacs and Guile communities, and whether it would cause splitting in the community if Emacs were extensible in programming languages other than Emacs Lisp. GNU make can be built with support for GNU Guile as an embedded extension language. C (programming language) This

5330-652: The preprocessing phase. Comments may appear either between the delimiters /* and */ , or (since C99) following // until the end of the line. Comments delimited by /* and */ do not nest, and these sequences of characters are not interpreted as comment delimiters if they appear inside string or character literals. C source files contain declarations and function definitions. Function definitions, in turn, contain declarations and statements . Declarations either define new types using keywords such as struct , union , and enum , or assign types to and perhaps reserve storage for new variables, usually by writing

5412-408: The recognizable expression and statement syntax of C with underlying type systems, data models, and semantics that can be radically different. The origin of C is closely tied to the development of the Unix operating system, originally implemented in assembly language on a PDP-7 by Dennis Ritchie and Ken Thompson , incorporating several ideas from colleagues. Eventually, they decided to port

5494-613: The same newsgroup; some may keep posts for as little as one or two weeks, others may hold them for many years. Back when the early community was the pioneering computer society, the common habit seen with many posts was a notice at the end that disclosed whether the author had (or was free of) a personal interest (financial, political or otherwise) in making the post. This is rarer now, and the posts must be read more skeptically, as with other media. Privacy and phishing issues have also risen in importance. Usenet newsgroups posters and operators usually do not make money from their occupations on

5576-399: The servers would be flooded; thus it is acceptable and often encouraged for users to just leech . There were originally a number of obstacles to the transfer of binary files over Usenet. Usenet was originally designed with the transmission of text in mind, and so the encoding of posts caused losses in binary data where the data was not part of the protocol's character set . Consequently, for

5658-415: The thing being referenced. C program source text is free-form code. Semicolons terminate statements , while curly braces are used to group statements into blocks . The C language also exhibits the following characteristics: While C does not include certain features found in other languages (such as object orientation and garbage collection ), these can be implemented or emulated, often through

5740-468: The type followed by the variable name. Keywords such as char and int specify built-in types. Sections of code are enclosed in braces ( { and } , sometimes called "curly brackets") to limit the scope of declarations and to act as a single statement for control structures. As an imperative language, C uses statements to specify actions. The most common statement is an expression statement , consisting of an expression to be evaluated, followed by

5822-476: The urging of Alan Snyder and also in recognition of the usefulness of the file-inclusion mechanisms available in BCPL and PL/I . Its original version provided only included files and simple string replacements: #include and #define of parameterless macros. Soon after that, it was extended, mostly by Mike Lesk and then by John Reiser, to incorporate macros with arguments and conditional compilation . Unix

5904-715: The use of external libraries (e.g., the GLib Object System or the Boehm garbage collector ). Many later languages have borrowed directly or indirectly from C, including C++ , C# , Unix's C shell , D , Go , Java , JavaScript (including transpilers ), Julia , Limbo , LPC , Objective-C , Perl , PHP , Python , Ruby , Rust , Swift , Verilog and SystemVerilog (hardware description languages). These languages have drawn many of their control structures and other basic features from C. Most of them also express highly similar syntax to C, and they tend to combine

5986-541: The use on a K&R C-based compiler of features available only in Standard C. After the ANSI/ISO standardization process, the C language specification remained relatively static for several years. In 1995, Normative Amendment 1 to the 1990 C standard (ISO/IEC 9899/AMD1:1995, known informally as C95) was published, to correct some details and to add more extensive support for international character sets. The C standard

6068-560: Was a limit on the size of individual posts so that large files could not be sent as single posts. To get around this, Newsreaders were developed which were able to split long files into several posts. Intelligent newsreaders at the other end could then automatically group such split files into single files, allowing the user to easily retrieve the file. These advances have meant that Usenet is used to send and receive many terabytes of files per day. There are two main issues that pose problems for transmitting large files over newsgroups. The first

6150-513: Was augmented to include the style used in C++, the K&R interface continued to be permitted, for compatibility with existing source code. C89 is supported by current C compilers, and most modern C code is based on it. Any program written only in Standard C and without any hardware-dependent assumptions will run correctly on any platform with a conforming C implementation, within its resource limits. Without such precautions, programs may compile only on

6232-416: Was based on Aubrey Jaffer's Scheme implementation SCM (which in turn was based on George Carrette's SIOD ). Lord convinced Richard Stallman to make GEL the official extension language of the GNU project, based on the argument that Scheme was a cleaner Lisp dialect than Emacs Lisp, and that GEL could evolve to implement other languages on the same runtime, namely Emacs Lisp. After Lord discovered GEL had

6314-438: Was created for the discussion of the humanities (e.g. literature, philosophy), and the Big 7 became the Big 8. The alt.* hierarchy has discussion of all kinds of topics, and many hierarchies for discussion specific to a particular geographical area or in a language other than English. Before a new Big 8 newsgroup can be created, an RFD (Request For Discussion) must be posted into the newsgroup news.announce.newgroups , which

6396-706: Was further revised in the late 1990s, leading to the publication of ISO/IEC 9899:1999 in 1999, which is commonly referred to as " C99 ". It has since been amended three times by Technical Corrigenda. C99 introduced several new features, including inline functions , several new data types (including long long int and a complex type to represent complex numbers ), variable-length arrays and flexible array members , improved support for IEEE 754 floating point, support for variadic macros (macros of variable arity ), and support for one-line comments beginning with // , as in BCPL or C++. Many of these had already been implemented as extensions in several C compilers. C99

6478-511: Was not available at the time, and Thompson modified the syntax to be less 'wordy' and similar to a simplified ALGOL known as SMALGOL. He called the result B , describing it as "BCPL semantics with a lot of SMALGOL syntax". Like BCPL, B had a bootstrapping compiler to facilitate porting to new machines. Ultimately, few utilities were written in B because it was too slow and could not take advantage of PDP-11 features such as byte addressability. In 1971 Ritchie started to improve B, to use

6560-628: Was one of the first operating system kernels implemented in a language other than assembly . Earlier instances include the Multics system (which was written in PL/I ) and Master Control Program (MCP) for the Burroughs B5000 (which was written in ALGOL ) in 1961. In around 1977, Ritchie and Stephen C. Johnson made further changes to the language to facilitate portability of the Unix operating system. Johnson's Portable C Compiler served as

6642-456: Was released with a new optimizing compiler and high-performance register virtual machine. According to the release announcement by Andy Wingo, real-world programs often showed a speedup of 30% or more with Guile 2.2 when compared to the previous 2.0 series. Guile 2.2.0 also lowered memory usage, sped up the "eval" interpreter, provided better support for multi-core programming, and removed any fixed limit on recursive function calls. It also supported

6724-530: Was written, and the language was renamed C. The C compiler and some utilities made with it were included in Version 2 Unix , which is also known as Research Unix . At Version 4 Unix , released in November 1973, the Unix kernel was extensively re-implemented in C. By this time, the C language had acquired some powerful features such as struct types. The preprocessor was introduced around 1973 at

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