% url.sty  ver 0.4    10-Nov-1995   Donald Arseneau   asnd@reg.triumf.ca
%
% A form of \verb that allows linebreaks at certain characters or 
% combinations of characters, accepts reconfiguration, and can often 
% be used in the argument to another command.  It is intended for 
% email addresses, hypertext links, directories/paths, etc., which 
% normally have no spaces.  The font may be selected using the \urlstyle 
% command, and new url-like commands can be defined using \urldef.
%
% Usage:    Conditions:
% \url{ }   If the argument contains any "%", "#", or "^^", or ends with
%           "\", it can't be used in the argument to another command.  
%           The argument must not contain unbalanced braces.
% \url|  |  ...where "|" is any character not used in the argument and not 
%           "{".  The same restrictions as above except that the argument
%           may contain unbalanced braces.
% \xyz      for "\xyz" a defined-url;  this can be used anywhere, no matter
%           what characters it contains.
% 
% See further instructions after "\endinput"

\def\url@ttstyle{%
\def\UrlFont{\@ifundefined{mathtt}{\tt}{\mathtt\relax}}% 
\def\UrlBreaks{\do\.\do\@\do\\\do\/\do\!\do\_\do\|\do\%\do\;\do\>\do\]%
 \do\)\do\,\do\?\do\'\do\+\do\=}%
\def\UrlBigBreaks{\do\:}%
\def\UrlNoBreaks{\do\(\do\[\do\{\do\<}% (unnecessary)
\def\UrlSpecials{\do\ {\ }}%
\def\UrlOrds{\do\*\do@url@hyp}% any ordinary characters that aren't usually
}

\def\url@rmstyle{%
\def\UrlFont{\fam\z@}% defs for roman font 
\def\UrlBreaks{\do\.\do\@\do\/\do\!\do\%\do\;\do\]\do\)\do\,\do\?\do+\do\=}%
\def\UrlBigBreaks{\do\:}%
\def\UrlNoBreaks{\do\(\do\[\do\{}% prevents breaks after *next* character
\def\UrlSpecials{\do\<{\langle}\do\>{\rangle\penalty\relpenalty}\do\_{\_%
 \penalty\@m}\do\|{\mid}\do\{{\lbrace}\do\}{\rbrace\penalty\relpenalty}\do
 \\{\mathbin{\backslash}}\do\~{\mathord{\sim}}\do\ {\ }}%
\def\UrlOrds{\do@url@hyp\do\'\do\"}%
}

\def\do@url@hyp{\do\-}% by default, no breaks after hyphens
\def\url@sfstyle{\url@rmstyle 
 \def\UrlFont{\@ifundefined{mathsf}{\sf}{\mathsf\relax}}}% 

% Alternative, if character status unknown:
% \def\UrlOrds{%
%   \@tempcnta\fam \multiply\@tempcnta\@cclvi \count@\m@ne 
%   \@whilenum \count@<\url@maxchar \do % set all characters as ordinary-tt
%    {\advance\count@\@ne \mathcode\count@\@tempcnta \advance\@tempcnta\@ne}%
%  }

\@ifundefined{noboundary}{\chardef\url@maxchar127 }{\chardef\url@maxchar255 }
\@ifundefined{strip@prefix}{\def\strip@prefix#1>{}}{}
\@ifundefined{verbatim@nolig@list}{\def\verbatim@nolig@list{\do\`}}{}

\def\Url{\relax\ifmmode\@nomatherr\else$\fi 
 \let\math@bgroup\relax \let\math@egroup\relax % force no-argument mode!
 \UrlFont \ifnum\fam<\z@ \fam\z@ \textfont\z@\font 
 \else \textfont\z@\textfont\fam\fi
 \let\do\@makeother \dospecials % verbatim catcodes
 \catcode`{\@ne \catcode`}\tw@ \catcode`\ 12 % except braces and spaces
 \medmuskip0mu \thickmuskip\medmuskip \thinmuskip\medmuskip
 \@tempcnta\fam\multiply\@tempcnta\@cclvi 
 \let\do\set@mathnolig \verbatim@nolig@list % prevent ligatures 
 \let\do\set@mathcode \UrlOrds % ordinary characters that were special
 \advance\@tempcnta 8192 \UrlBreaks % bin
 \advance\@tempcnta 4096 \UrlBigBreaks % rel
 \advance\@tempcnta 4096 \UrlNoBreaks % open
 \let\do\set@mathact \UrlSpecials % active
 \@ifnextchar\bgroup\Url@z\Url@y}

\def\Url@y#1{\catcode`{11 \catcode`}11
  \def\@tempa##1#1{\Url@z{##1}}\@tempa}
\def\Url@z#1{\def\@tempa{#1 }\let\@tempb\@empty
  \expandafter\expandafter\expandafter\Url@s
  \expandafter\strip@prefix\meaning\@tempa $ \m@th$\endgroup}
\def\Url@s#1$ {#1} 

\def\Urldef#1#2{\begingroup \setbox\z@\hbox\bgroup
 \def\url@command{#2}\def\url@type{#1}%
 \let\Url@z\Url@def #1}
\def\Url@def#1{\toks@\expandafter{\url@type{#1}}%
  \expandafter\xdef\url@command{\the\toks@}%
  \m@th$\endgroup\egroup\endgroup}

\def\set@mathcode#1{\count@`#1\advance\count@\@tempcnta\mathcode`#1\count@}
\def\set@mathact#1#2{\mathcode`#132768 
  \lccode`\~`#1\lowercase{\def~{#2}}}
\def\set@mathnolig#1{\mathcode`#132768 \lccode`\~`#1\relax
 \count@`#1\advance\count@\@tempcnta 
 \lowercase{\edef~{{\mathchar\number\count@\kern\z@}}}}

\def\urlstyle#1{\csname url@#1style\endcsname}

% Sample configuration:

\newcommand\url{\begingroup \Url}
\newcommand\urldef{\Urldef\url}
%
\newcommand\path{\begingroup \urlstyle{tt}\Url}
\newcommand\pathdef{\Urldef\path}

% \newcommand\email{\begingroup \urlstyle{rm}\Url}

% Process LaTeX \package options

\urlstyle{tt}
\@ifundefined{ProvidesPackage}{}{
  \ProvidesPackage{url}[1995/11/10 \space \space 
       Verb mode for url and email addresses]
  \DeclareOption{hyphens}{\def\do@url@hyp{}}% allow breaks after hyphens
  \DeclareOption{obeyspaces}{\let\Url@s\relax}
  \ProcessOptions
\ifx\Url@s\relax \def\Url@s#1 {\ifx$#1\@empty\else
  \@tempb\def\@tempb{\penalty\relpenalty\ }#1\expandafter\Url@s\fi}\fi
}

\endinput
%
% url.sty  ver 0.4    10-Nov-1995   Donald Arseneau   asnd@reg.triumf.ca
%
% This package defines "\url", a form of "\verb" that allows linebreaks,
% and can often be used in the argument to another command.  It can be
% configured to print in different formats.  It is particularly useful for hypertext
% links, email addresses, directories/paths, etc. The font may be selected
% using the "\urlstyle" command and pre-defined text can be stored with the
% "\urldef" command. New url-like commands can be defined, and a "\path"
% command is provided this way. 
%
% Usage:    Conditions:
% \url{ }   If the argument contains any "%", "#", or "^^", or ends with 
%           "\", it can't be used in the argument to another command.  
%           The argument must not contain unbalanced braces.
% \url|  |  ...where "|" is any character not used in the argument and not 
%           "{".  The same restrictions as above except that the argument
%           may contain unbalanced braces.
% \xyz      for "\xyz" a defined-url;  this can be used anywhere, no matter
%           what characters it contains.
% 
% Package Option:  obeyspaces
% Ordinarily, all spaces are ignored in the url-text.  The "[obeyspaces]" 
% option allows spaces, but may introduce spurious spaces if there are any 
% "\" in the text and the "\url" appears in the argument to another command.
% So if you need to obey spaces and have no "\" characters, you should say
% "\usepackage[obeyspaces]{url}".  If you need both spaces and backslashes,
% use a `defined-url' for anything with "\".
%
% Package Option:  hyphens
% Ordinarily, breaks are not allowed after "-" characters because this 
% leads to confusion. (Is the "-" part of the address or just a hyphen?")  
% The package option "[hyphens]" allows breaks after hyphen characters. 
% The "\url" command will *never ever* hyphenate words.
% 
% Defining a defined-url:
% Take for example the email address "myself%node@gateway.net" which could
% not be given (using "\url" or "\verb") in a caption or parbox due to the
% percent sign.  However, this address can be predefined elsewhere in the 
% document with
%    \urldef{\myself}{myself%node@gateway.net}    or
%    \urldef{\myself}|myself%node@gateway.net|
% and then you may use the command "\myself" in a caption.
%
% Style: 
% You can switch the style of printing using "\urlstyle{tt}", where the
% "tt" can be any defined style.  The pre-defined styles are tt, rm, and 
% sf, which all allow the same linebreaks but different fonts.  You can 
% define styles with different fonts and/or breakpoints by redefining 
% the commands "\UrlFont" and "\UrlBreaks" etc., either directly or in a 
% style-changing macro modelled on "\url@ttstyle" and "\url@rmstyle", and 
% the explanations below.  The "\url" command follows whatever the 
% currently-set style dictates.
%
% Alternate commands:
% It may be desireable to have different things treated differently, each
% in a predefined style; e.g., if you want directory paths to always be 
% in tt and email addresses to be rm, then you would define new url-like
% commands as follows:
%
%    \newcommand\email{\begingroup \urlstyle{rm}\Url}
%    \newcommand\directory{\begingroup \urlstyle{tt}\Url}
%
% You must follow this format closely, and NOTE that the final command is 
% "\Url", not "\url".  In fact, the "\directory" example is exactly the 
% "\path" definition which is pre-defined in the package.  If you look 
% above, you will see that "\url" is defined with
%    \newcommand\url{\begingroup \Url}
% I.e., using whatever style has been selected.
%
% In order to make a defined-url for these other styles, you would use the
% capitalized "\Urldef" command as in this example:
%
%    \Urldef{\email}{\myself}{myself%node.domain@gateway.net}
%
% which makes "\myself" act like "\email{myself%node.domain@gateway.net}",
% if the "\email" command is defined as above.  
% To go with the "\path" command, this package defines "\pathdef" as
% a shorthand for "\Urldef{\path}".
%
% Defining styles:
% To change the font or the list of characters that allow linebreaks, you
% should define a `url-style' (following the example of "\url@ttstyle" and
% "\url@rmstyle") which defines all of "\UrlBigbreaks", "\UrlNoBreaks", 
% "\UrlBreaks", "\UrlSpecials", and "\UrlFont".
%
% Changing font:
% The "\UrlFont" command selects the font; be aware that this is a 
% *math-mode* switch, not taking an argument. The default definition 
% of \UrlFont for tt type is complicated in order to handle various font 
% selection schemes and different versions of LaTeX.  In addition to 
% setting "\UrlFont", some characters will probably need to be defined 
% in the "\UrlSpecials" list because most fonts don't have all standard 
% characters.  See the definition of "\url@rmstyle", which implements 
% "\urlstyle{rm}".  The nominal format for each special character "c" 
% is: "\do\c{<definition>}", but you can include other definitions.
%
% Changing linebreaks:
% The list of characters that allow line-breaks is given by \UrlBreaks 
% and \UrlBigBreaks, which have the format "\do\c" for character "c". 
% The differences are that `BigBreaks' have a lower penalty and have 
% different breakpoints when in sequence (as in "http://"): `BigBreaks' 
% are treated as mathrels while `Breaks' are mathbins (see The TeXbook, 
% p.170). In particular, a series of `BigBreak' characters will break at 
% the end and only at the end; a series of `Break' characters will break 
% after the first and after every following *pair*; there will be no 
% break after a `Break' character if a `BigBreak' follows.  In the case 
% of "http://" it doesn't matter whether ":" is a `Break' or `BigBreak' --
% the breaks are the same in either case; but for DECnet nodes with "::"
% it is important to prevent breaks *between* the colons, and that is why 
% colons are `BigBreaks'.
%
% It is possible for characters to prevent breaks after the next following 
% character (I use this for parentheses).  Specify these in "\UrlNoBreaks". 
%
% You can do arbitrarily complex things with characters by making them 
% active in math mode (mathcode hex-8000) and specifying the definition(s)
% in "\UrlSpecials".  This is used in the rm and sf styles to handle 
% several characters that are not present in fonts.
%
% If all this sounds confusing ... well, it is!  But I hope you won't need 
% to redefine breakpoints -- the default assignments seem to work well for 
% a wide variety of applications.  If you do need to make changes, you can 
% test for breakpoints using regular math mode and the characters "+=(a".
