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author | Karl Berry <karl@freefriends.org> | 2010-09-24 00:06:55 +0000 |
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committer | Karl Berry <karl@freefriends.org> | 2010-09-24 00:06:55 +0000 |
commit | 41d4e60fba44409eb9361200ff517a6bf67936c6 (patch) | |
tree | c2feeef423a6f27a89cdc9816fd354a2f59187be /Master/texmf-dist/tex/generic/path/path.sty | |
parent | ed89e18f4912e0485a4cd0cd3553a12658a32701 (diff) |
now in generic (23sep10)
git-svn-id: svn://tug.org/texlive/trunk@19866 c570f23f-e606-0410-a88d-b1316a301751
Diffstat (limited to 'Master/texmf-dist/tex/generic/path/path.sty')
-rw-r--r-- | Master/texmf-dist/tex/generic/path/path.sty | 333 |
1 files changed, 333 insertions, 0 deletions
diff --git a/Master/texmf-dist/tex/generic/path/path.sty b/Master/texmf-dist/tex/generic/path/path.sty new file mode 100644 index 00000000000..19b0fe178ac --- /dev/null +++ b/Master/texmf-dist/tex/generic/path/path.sty @@ -0,0 +1,333 @@ +%%% @LaTeX-style-file +%%% { +%%% author = "Philip Taylor", +%%% version = "3.03b", +%%% date = "22 July 1997", +%%% time = "15:59:31 BST", +%%% filename = "path.sty", +%%% address = "The Computer Centre +%%% RHBNC, University of London +%%% Egham Hill +%%% Egham, Surrey TW20 0EX, ENGLAND", +%%% telephone = "Tel: +44 1784 443172", +%%% FAX = "Fax: +44 1784 434348", +%%% email = "P.Taylor@Vms.Rhbnc.Ac.Uk", +%%% codetable = "ISO/ASCII", +%%% keywords = "file name, filename, path name, pathname, +%%% discretionary, discretionaries", +%%% supported = "yes", +%%% docstring = {Computer filenames, host names, and e-mail +%%% addresses tend to be long strings that +%%% cause line breaking problems for TeX. +%%% Sometimes rather long strings are +%%% encountered, such as: +%%% +%%% mighty-mouse-gw.scrc.symbolics.com +%%% +%%% This file defines a macro, \path|...|, +%%% similar to LaTeX's \verb|...| macro, that +%%% sets the text in the typewriter font, +%%% allowing hyphen-less line breaks at +%%% punctuation characters. +%%% +%%% The default set of punctuation characters is +%%% defined as +%%% +%%% \discretionaries |~!@$%^&*()_+`-=#{"}[]:;'<>,.?\/| +%%% +%%% However, you can change it as needed, for +%%% example +%%% +%%% \discretionaries +@%!.+ +%%% +%%% would assign to it the set @ % ! . which +%%% commonly occur in electronic mail addresses. +%%% +%%% The delimiter characters surrounding the +%%% arguments to \discretionaries and \path +%%% will normally be a punctuation character not +%%% found in the argument, and not otherwise +%%% significant to TeX. In particular, backslash +%%% cannot be used as a delimiter. In the rare +%%% event that this is required, set +%%% +%%% \specialpathdelimiterstrue +%%% +%%% This practice is not recommended, because TeX +%%% then runs about four times slower while it is +%%% typesetting \path\...\ requests. +%%% \specialpathdelimitersfalse is the normal +%%% setting. +%%% +%%% This file may be used in Plain TeX or AmSTeX +%%% by +%%% +%%% \input path.sty +%%% +%%% and in LaTeX by +%%% +%%% \usepackage {path} +%%% +%%% The checksum field above, if present, contains +%%% a CRC-16 checksum as the first value, followed +%%% by the equivalent of the standard UNIX wc (word +%%% count) utility output of lines, words, and +%%% characters. This is produced by Robert +%%% Solovay's checksum utility. +%%% } +%%% } +%%% ==================================================================== + +% ====================================================================== +% +% The \path Macro +% +% An early prototype of this code which was developed by Nelson H. F. +% Beebe <beebe@math.utah.edu> used a recursive macro to peel off one +% character at a time, then with a nest of \ifx statements, test for +% each punctuation character, and if one is found, insert discretionary +% linebreaks in the form of \- or \penalty0. While this usually works, +% it is not entirely satisfactory, because the nested \ifx statements +% are ugly, and the recursion can exhaust TeX's macro stack for +% arguments longer than about 30 characters. +% +% A second version by NHFB built upon the ideas used by the LaTeX +% \verb|...| macro; this was mostly successful, but was flawed by its +% inability to handle at least the three characters ^ [ ], by loss of +% use of @ for naming internal private macros, and by its inability to +% allow the set of characters at which breaks are permissible. +% +% The problem was then passed off to Philip Taylor, who wrote this third +% version which fully solves the problem. Phil therefore gets the +% author credit in the file header above. [Gee, thanks ! ** Phil] +% +% Revision history (reverse time order): +% +% 3.03b [22-Jul-1997] +% Summary: No code changes. An out-of-date example removed, the syntax +% for LaTeX2e changed to "\usepackage {path}", and the "checksum" +% comments modified to indicate that the checksum is not necessarily +% present. The initial opening brace re-positioned to align +% with the matching closing brace, and the inner closing brace +% re-positioned to align with the inner opening brace. A check made +% to ensure that no <tab> characters are present. +% +% 3.03a [22-Jul-1997] +% Summary: No code changes from V3.03; e-mail addresses, telephone numbers, +% etc. amended to reflect current situation. Checksum removed. +% +% 3.03 [03-Dec-1991] +% Problem: A \path|...| entry in a LaTeX index is set with an +% preceding blank line. +% Solution: Add \leavevmode before \hbox{}; without it, an extra blank +% line gets typeset before every invocation of \path in a +% LaTeX theindex environment. +% Diagnosis: To avoid hyphenation, the expansion of \path starts with +% an \hbox{} (c.f. the TeXbook, p. 454); LaTeX indices are +% basically set in vertical mode, with each index entry a +% paragraph in its own right; when an \hbox {} is +% encountered in vmode, it is typeset in vmode, and TeX +% continues; the first real character is encountered, and +% TeX enters unrestricted horizontal mode. The \hbox {} and +% the first character are therefore on separate lines, +% separated by \baselineskip. +% +% 3.02 [23-Oct-1991 13:45:12] +% First released version. +% ====================================================================== + +\immediate\write16{This is path.sty, Version 3.03 <03-Dec-1991>} + +%%% We will regrettably need one \count variable with an open name, +%%% in which to save the category code of commercial-at ... + +\newcount \ATcode +\ATcode = \catcode `\@ + +%%% Make commercial-at a letter to provide concealed control sequences + +\catcode `\@ = 11 + +%%% and then declare two \count variables with concealed names + +\newcount \c@tcode +\newcount \c@unter + +%%% and a boolean variable with an open name, to specify the nature of +%%% the delimiters which will be associated with the \path command + +\newif \ifspecialpathdelimiters + +%%% We need to define control sequences which expand to both +%%% active and passive spaces ... + +\begingroup +\catcode `\ = 10 +\gdef \passivesp@ce { } +\catcode `\ = 13\relax% +\gdef\activesp@ce{ }% +\endgroup + +%%% \discretionaries will define a macro \discr@ti@n@ri@s which will +%%% make every character between the first and final <delim> a +%%% discretionary breakpoint. + +\def \discretionaries %%% <delim> <chars> <delim> + % start a group (ended in \discr@ti@naries ), + % make every character (apart from space) active, + % then transfer control to \discr@tionaries ... + {\begingroup + \c@tcodes = 13 + \discr@tionaries + } + +%%% \discr@tionaries will receive as parameter the initial <delim> +%%% which will delimit the set of discretionaries; this <delim> +%%% will be active. + +\def \discr@tionaries #1%%% <delim> + % knowing the initial <delim>, define \discr@ti@naries with a + % delimited parameter structure, the final delimiter being + % the second instance of <delim> + {\def \discr@ti@naries ##1#1%%% <chars> <delim> + % \discr@ti@naries will receive as parameter the set of + % characters which are to be made discretionaries; it ends the + % group and then defines \discr@ti@n@ries, a tail-recursive + % macro, which will quietly process each of the + % discretionaries in turn ... + {\endgroup + \def \discr@ti@n@ries ####1%%% <char> or <delim> + % by checking to see if it has reached the end of the + % list, i.e. comparing its parameter with the known final + % <delim> ... + {\if \noexpand ####1\noexpand #1% + % if they match, there is no more to do ... + \let \n@xt = \relax + \else + % otherwise the character becomes active and is + % defined as a discretionary with the three texts + % <self> <empty> <self>, thus suppressing true + % hyphenation; the macro then prepares to process + % the next character. + \catcode `####1 = 13 + \def ####1{\discretionary + {\char `####1}{}{\char `####1}}% + \let \n@xt = \discr@ti@n@ries + \fi + % here either tail recursion occurs, if there are more + % characters to process, or tail recursion ceases if all + % have been exhausted + \n@xt + }% + % of course, none of this must take place during the \stress + % {call} of \discretionaries; execution is deferred until + % another macro such as \path calls the concealed action + % macro \discr@ti@n@ri@s; we therefore define this macro to + % have the desired effect. + \def \discr@ti@n@ri@s {\discr@ti@n@ries ##1#1}% + }% + % and finally invoke \discr@ti@naries to process the set of + % discretionary characters; it will take everything up to the + % second instance of <delim> as its parameter (and therefore as the + % set of characters to be processed). + \discr@ti@naries + } + +%%% \path, which is the user interface to \p@th, first checks +%%% to see whether \specialpathdelimiters is <true> or <false>; +%%% if <true>, it needs to take special action to ensure that +%%% \stress {all} characters (apart from <space>) are acceptable +%%% as delimiters; this is very time-consuming, and should be +%%% avoided if at all possible. It also defines \endp@th, to +%%% close the appropriate number of groups, and finally transfers +%%% control to \p@th + +\def \path + {\ifspecialpathdelimiters + \begingroup + \c@tcodes = 12 + \def \endp@th {\endgroup \endgroup}% + \else + \let \endp@th = \endgroup + \fi + \p@th + } + +%%% \p@th, which has essentially the same syntax as \discretionaries, +%%% expects to be followed by a <delim>, a <path>, and a second instance +%%% of <delim>; it will typeset <path> in the \tt font with hyphenation +%%% inhibited --- breaks (but not true hyphenation) are allowed at any +%%% or all of the special characters which have +%%% previously been declared as \discretionaries. + +\def \p@th #1%%% <delim> + % it starts by opening a group (ended in \p@@th) ... + % switches to \tt, and inhibits hyphenation; + % allows breaks at \discretionaries; saves the + % catcode of the initial <delim>, because if it has also been + % declared within \discretionaries, the initial and final <delim> + % won't match (which would be a disaster); \c@tcode is overloaded, + % but there is no conflict that I can detect ... + % invokes \discr@ti@n@ri@s to render active the set of special + % characters which have previously been declared as + % \discretionaries; each of these characters will expand to a real + % \discretionary, with replacement texts <self> <null> <self>; and + % re-instates the catcode of the initial <delim>. + {\begingroup + \tt + \c@tcode = \catcode `#1 + \discr@ti@n@ri@s + \catcode `\ = \active + \expandafter \edef \activesp@ce {\passivesp@ce \hbox {}}% + \catcode `#1 = \c@tcode + % it next defines an inner macro \p@@th with delimited parameter + % structure, the final delimiter being the same as the initial + % delimiter which it has itself received as #1. + \def \p@@th ##1#1% <chars> <delim> + % Within \p@@th, + % permissible breakpoints are specified, + % the path is typeset, + % and the group(s) ended. + {\leavevmode \hbox {}##1% + \endp@th + }% + \p@@th + } + +%%% \c@tcodes expects to be followed by the r-h-s of a numeric +%%% assignment optionally including the assignment operator; it saves +%%% the value of the r-h-s in \c@tcode, and invokes \c@tc@des. + +\def \c@tcodes {\afterassignment \c@tc@des \c@tcode} + +%%% \c@tc@des uses the value saved in \c@tcode, and assigns it to the +%%% \catcode of all characters with the single exception of <space>, +%%% which retains its normal catcode of 10; on exit, every single +%%% character apart from <space> will have the catcode which followed +%%% \c@tcodes. The code is optimised to avoid unnecessary usage of +%%% save-stack space. + +\def \c@tc@des + {\c@unter = 0 + \loop + \ifnum \catcode \c@unter = \c@tcode + \else + \catcode \c@unter = \c@tcode + \fi + \ifnum \c@unter < 255 + \advance \c@unter by 1 + \repeat + \catcode `\ = 10 + } + +%%% We restore the original catcode of commercial-at + +\catcode `\@ = \ATcode + +%%% Define a default set of discretionary break characters +%%% to include all punctuation characters except vertical +%%% bar + +\discretionaries |~!@$%^&*()_+`-=#{}[]:";'<>,.?\/| + +\endinput |