TANGLE(1)
NAME
tangle - translate WEB to Pascal
SYNOPSIS
tangle [ options ] webfile[.web] [ changefile[.ch] ]
DESCRIPTION
This manual page is not meant to be exhaustive. The complete documentation for this version of TeX can be found in the info file or manual Web2C: A TeX implementation.
The tangle program converts a Web source document into a Pascal program
that may be compiled in the usual way with the on-line Pascal compiler
(e.g., pc(1)). The output file is packed into lines of 72 characters
or less, with the only concession to readability being the termination
of lines at semicolons when this can be done conveniently.
The Web language allows you to prepare a single document containing all
the information that is needed both to produce a compilable Pascal program and to produce a well-formatted document describing the program in
as much detail as the writer may desire. The user of Web must be
familiar with both TeX and Pascal. Web also provides a relatively simple, although adequate, macro facility that permits a Pascal program to
be written in small easily-understood modules.
The command line should have either one or two names on it. The first
is taken as the Web file (and .web is added if there is no extension).
If there is another name, it is a change file (and .ch is added if
there is no extension). The change file overrides parts of the Web
file, as described in the Web system documentation.
The output files are a Pascal file and a string pool file, whose names
are formed by adding .p and .pool respectively to the root of the Web
file name.
OPTIONS
This version of tangle understands the following options. Note that
some of these options may render the output unsuitable for processing
by a Pascal compiler.
--help Print help message and exit.
- --length number
- Compare only the first number characters of identifiers when checking for collisions. The default is 32, the original tangle used 7.
- --loose
- When checking for collisions between identifiers, honor the settings of the --lowercase, --mixedcase, --uppercase, and --under-line options. This is the default.
- --lowercase
- Convert all identifiers to lowercase.
- --mixedcase
- Retain the case of identifiers. This is the default.
- --strict
- When checking for collisions between identifiers, strip underlines and convert all identifiers to uppercase first.
- --underline
- Retain underlines (also known as underscores) in identifiers.
- --uppercase
- Convert all identifiers to uppercase. This is the behaviour of the original tangle.
- --version
- Print version information and exit.
SEE ALSO
pc(1), pxp(1) (for formatting tangle output when debugging), tex(1).
Donald E. Knuth, The Web System of Structured Documentation.
Donald E. Knuth, Literate Programming, Computer Journal 27, 97-111,
1984.
Wayne Sewell, Weaving a Program, Van Nostrand Reinhold, 1989, ISBN
0-442-31946-0.
Donald E. Knuth, TeX for nroff: The Program (Volume B of Computers and Typesetting), Addison-Wesley, 1986, ISBN 0-201-13437-3.
Donald E. Knuth, Metafont: The Program (Volume D of Computers and Typesetting), Addison-Wesley, 1986, ISBN 0-201-13438-1.
These last two are by far the largest extant examples of Web programs.
There is an active Internet electronic mail discussion list on the subject of literate programming; send a subscription request to litprogrequest@shsu.edu to join.
AUTHORS
- Web was designed by Donald E. Knuth, based on an earlier system called
DOC (implemented by Ignacio Zabala). The tangle and weave programs are
themselves written in Web. The system was originally ported to Unix at
Stanford by Howard Trickey, and at Cornell by Pavel Curtis.