Web is a

computer programming Computer programming is the process of performing a particular computation (or more generally, accomplishing a specific computing result), usually by designing and building an executable computer program. Programming involves tasks such as anal ...

system created by Donald E. Knuth as the first implementation of what he called "

literate programming Literate programming is a programming paradigm introduced in 1984 by Donald Knuth in which a computer program is given as an explanation of its logic in a natural language, such as English, interspersed (embedded) with snippets of macros and t ...

": the idea that one could create

software Software is a set of computer programs and associated software documentation, documentation and data (computing), data. This is in contrast to Computer hardware, hardware, from which the system is built and which actually performs the work. ...

as works of

literature Literature is any collection of written work, but it is also used more narrowly for writings specifically considered to be an art form, especially prose fiction, drama, and poetry. In recent centuries, the definition has expanded to inclu ...

, by embedding source code inside descriptive text, rather than the reverse (as is common practice in most

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

), in an order that is convenient for exposition to human readers, rather than in the order demanded by the

compiler In computing, a compiler is a computer program that translates computer code written in one programming language (the ''source'' language) into another language (the ''target'' language). The name "compiler" is primarily used for programs that ...

. Web consists of two secondary programs: TANGLE, which produces compilable

Pascal Pascal, Pascal's or PASCAL may refer to: People and fictional characters * Pascal (given name), including a list of people with the name * Pascal (surname), including a list of people and fictional characters with the name ** Blaise Pascal, Frenc ...

code from the source texts, and WEAVE, which produces nicely-formatted, printable documentation using

TeX Tex may refer to: People and fictional characters * Tex (nickname), a list of people and fictional characters with the nickname * Joe Tex (1933–1982), stage name of American soul singer Joseph Arrington Jr. Entertainment * ''Tex'', the Italian ...

. CWEB is a version of Web for the

C programming language ''The C Programming Language'' (sometimes termed ''K&R'', after its authors' initials) is a computer programming book written by Brian Kernighan and Dennis Ritchie, the latter of whom originally designed and implemented the language, as well as ...

, while noweb is a separate literate programming tool, which is inspired by Web (as reflected in the name) and which is language agnostic. The most significant programs written in Web are

and Metafont. Modern TeX distributions use another program

Web2C TeX Live is a cross-platform, free software distribution for the TeX typesetting system that includes major TeX-related programs, macro packages, and fonts. It is the replacement of its no-longer supported counterpart teTeX. It is now the defa ...

to convert Web source to C.

Philosophy

Unlike most other

documentation generators Documentation is any communicable material that is used to describe, explain or instruct regarding some attributes of an object, system or procedure, such as its parts, assembly, installation, maintenance and use. As a form of knowledge manageme ...

which relegate documentation to comments, the WEB approach is to write an article to document the making of the source code. Much like TeX articles, the source is divided into sections according to documentation flow. For example, in CWEB, code sections are seamlessly intermixed in the line of argumentation.

CWEB

CWEB is a

system created by

Donald Knuth Donald Ervin Knuth ( ; born January 10, 1938) is an American computer scientist, mathematician, and professor emeritus at Stanford University. He is the 1974 recipient of the ACM Turing Award, informally considered the Nobel Prize of computer ...

and Silvio Levy as a follow-up to Knuth's ''WEB''

system, using the

(and to a lesser extent the C++ and

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...

programming languages) instead of

. Like WEB, it consists of two primary programs: CTANGLE, which produces compilable C code from the source texts, and CWEAVE, which produces nicely-formatted printable documentation using

Features

* Can enter manual TeX code as well as automatic. * Make formatting of C code for pretty printing. * Can define sections, and can contain documentation and codes, which can then be included into other sections. * Write the header code and main C code in one file, and can reuse the same sections, and then it can be tangled into multiple files for compiling. * Use #line pragmas so that any warnings or errors refer to the .w source. * Include files. * Change files, which can be automatically merged into the code when compiling/printing. * Produces index of identifiers and section names in the printout.

References

External links

The TeX Catalogue entry for Web
Free documentation generators Literate programming TeX {{Soft-eng-stub