This is Spidery WEB, tool for building a WEB system for the language of your choice. It was probably gotten by anonymous ftp from the Comprehensive TeX Archive Network, possibly from niord.shsu.edu. My colleagues and I have used Spider to build WEB systems for Ada, C, AWK, and other languages. Spidery WEB is no longer supported; the lessons learned in its implementation and use have been applied to the design of `noweb', a much simpler literate-programming tool. noweb is available by anonymous ftp from csservices.princeton.edu:pub/noweb.shar.Z. ORA Corp makes some effort to keep Spidery WEB working; bug reports, fixes, and new language descriptions can be sent to spider-bugs@oracorp.com. The rest of this file contains a brief description of Spidery WEB and this distribution; more extensive documentation can be found in the doc subdirectory. INTRODUCTION Spider reads a description of a programming language, and writes source code for a Weave and Tangle which support that language. The language-dependent parts are derived from the description given Spider, and the language-independent parts are taken from ``master copies'' of Weave and Tangle. The master copies are derived from Silvio Levy's CWEB, and the Tangle and Weave that are constructed are implemented in C. Spider is implemented as an Awk program. An exhaustive list of Spidery Web's features would interest only Web experts, but I do want to mention some features that I hope will encourage people to use Spidery {\tt WEB}. Tangle and Weave can read from multiple files (this feature is present in Levy's CWEB), and Tangle can write to multiple files. Included files will be searched for on a path if not found in the current directory. These features make Spidery WEB more usable on systems that have make. TANGLE can expand macros with multiple parameters. TANGLE writes #line directives, so you can debug at the WEB source level if your compiler respects the C~conventions for #line. Many features of WEB seem to exist only to compensate for deficiencies in PASCAL, and most of those were dropped in CWEB. I have changed much of CWEB in order to avoid being bound too much by C conventions. As a result, there are dozens of minor differences between Spidery WEB and original WEB. To give just one example, Spidery WEB supports octal and hexadecimal constants using WEB-style notation, not the C notation used in CWEB. Spider can generate WEB systems for a variety of languages. The author has written Spider description files for C, AWK, Ada, SSL (a language that describes attribute grammars to the Cornell Synthesizer Generator), the Larch Shared Language (a language for describing equational theories), and Dijkstra's language of guarded commands. Debugging the grammar that WEAVE uses to prettyprint the language is the most time-consuming part of creating a WEB system for a new target language, and Spider makes it trivial to change that grammar. To make a Spider description file for an Algol-like language that uses infix expression notation, an experienced systems programmer should be able to adapt an existing Spider description file very quickly. Spider's major limitations are lexical. All Spidery WEBs assume that spaces and tabs in the input are not significant, except as separators; this makes it impossible to construct Spidery WEBs for languages like Fortran and Miranda, where the position of text on a line is significant. (You would have to modify the ``master copies'' of Tangle and Weave to change the lexical analyzer.) The lexical structures of identifiers, string literals, and numeric literals are fixed. Spider's major value is that is makes it possible to create a new WEB quickly, and to tinker with it easily. My colleagues and I have used Spidery WEB to write programs in Ada, C, and SSL, and has been pleased with the result. We have written in WEB an application of 24 thousand lines, and we are very pleased at how easy it has been to review and maintain this code. I hope that the availability of Spidery WEB will encourage other groups to try literate programming, and that they, too, will be pleased with the results. WHAT YOU GET Although Spider is complete and useful, this distribution contains bug fixes and enhancements that I have not folded into the code. I have tested this system only under Unix, but other users have provided Macintosh, MS-DOS, and OS/2 implementations. This directory contains: bug-reports reports of bugs that may or may not have been fixed doc manuals and articles about Spider fixes-to-be-applied bug fixes and enhancements mac Macintosh binaries ms-dos MS-DOS binaries os2 OS/2 source-code changes patches patches for old versions of Spider (now useless) src Spider source code & instructions for building Spider todo a wish list tools auxiliary tools that might be useful with Spidery WEB Send comments or bug reports to spider-bugs@oracorp.com Norman Ramsey