Source Code 1994 March/Source_Code_CD-ROM_Walnut_Creek_March_1994.iso/compsrcs/unix/volume26/funnlweb/part09

Text File | 1993-04-10 | 130.3 KB | 3,080 lines

Newsgroups: comp.sources.unix
From: [e-mail] (Ross Williams)
Subject: v26i129: funnelweb - a tool for literate programming in C, Part09/20
Sender: [e-mail]
Approved: [e-mail]

Submitted-By: [e-mail] (Ross Williams)
Posting-Number: Volume 26, Issue 129
Archive-Name: funnelweb/part09

#! /bin/sh
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# it by saving it into a file and typing "sh file".  To overwrite existing
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# Contents:  admin/gnu2.txt answers/ex16.tex answers/wv02.tex
#   hackman/h_ch2.tex hackman/h_ch4.tex sources/help_gnu.txt
#   sources/tangle.c
# Wrapped by [e-mail] on Sun Apr 11 11:00:22 1993
PATH=/bin:/usr/bin:/usr/ucb ; export PATH
if test -f 'admin/gnu2.txt' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'admin/gnu2.txt'\"
else
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sed "s/^X//" >'admin/gnu2.txt' <<'END_OF_FILE'
X            GNU GENERAL PUBLIC LICENSE
X               Version 2, June 1991
X
X Copyright (C) 1989, 1991 Free Software Foundation, Inc.
X                          675 Mass Ave, Cambridge, MA 02139, USA
X Everyone is permitted to copy and distribute verbatim copies
X of this license document, but changing it is not allowed.
X
X                Preamble
X
X  The licenses for most software are designed to take away your
freedom to share and change it.  By contrast, the GNU General Public
License is intended to guarantee your freedom to share and change free
software--to make sure the software is free for all its users.  This
General Public License applies to most of the Free Software
XFoundation's software and to any other program whose authors commit to
using it.  (Some other Free Software Foundation software is covered by
the GNU Library General Public License instead.)  You can apply it to
your programs, too.
X
X  When we speak of free software, we are referring to freedom, not
price.  Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
this service if you wish), that you receive source code or can get it
if you want it, that you can change the software or use pieces of it
in new free programs; and that you know you can do these things.
X
X  To protect your rights, we need to make restrictions that forbid
anyone to deny you these rights or to ask you to surrender the rights.
These restrictions translate to certain responsibilities for you if you
distribute copies of the software, or if you modify it.
X
X  For example, if you distribute copies of such a program, whether
gratis or for a fee, you must give the recipients all the rights that
you have.  You must make sure that they, too, receive or can get the
source code.  And you must show them these terms so they know their
rights.
X
X  We protect your rights with two steps: (1) copyright the software, and
X(2) offer you this license which gives you legal permission to copy,
distribute and/or modify the software.
X
X  Also, for each author's protection and ours, we want to make certain
that everyone understands that there is no warranty for this free
software.  If the software is modified by someone else and passed on, we
want its recipients to know that what they have is not the original, so
that any problems introduced by others will not reflect on the original
authors' reputations.
X
X  Finally, any free program is threatened constantly by software
patents.  We wish to avoid the danger that redistributors of a free
program will individually obtain patent licenses, in effect making the
program proprietary.  To prevent this, we have made it clear that any
patent must be licensed for everyone's free use or not licensed at all.
X
X  The precise terms and conditions for copying, distribution and
modification follow.
X
X            GNU GENERAL PUBLIC LICENSE
X   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
X
X  0. This License applies to any program or other work which contains
a notice placed by the copyright holder saying it may be distributed
under the terms of this General Public License.  The "Program", below,
refers to any such program or work, and a "work based on the Program"
means either the Program or any derivative work under copyright law:
that is to say, a work containing the Program or a portion of it,
either verbatim or with modifications and/or translated into another
language.  (Hereinafter, translation is included without limitation in
the term "modification".)  Each licensee is addressed as "you".
X
Activities other than copying, distribution and modification are not
covered by this License; they are outside its scope.  The act of
running the Program is not restricted, and the output from the Program
is covered only if its contents constitute a work based on the
Program (independent of having been made by running the Program).
Whether that is true depends on what the Program does.
X
X  1. You may copy and distribute verbatim copies of the Program's
source code as you receive it, in any medium, provided that you
conspicuously and appropriately publish on each copy an appropriate
copyright notice and disclaimer of warranty; keep intact all the
notices that refer to this License and to the absence of any warranty;
and give any other recipients of the Program a copy of this License
along with the Program.
X
You may charge a fee for the physical act of transferring a copy, and
you may at your option offer warranty protection in exchange for a fee.
X
X  2. You may modify your copy or copies of the Program or any portion
of it, thus forming a work based on the Program, and copy and
distribute such modifications or work under the terms of Section 1
above, provided that you also meet all of these conditions:
X
X    a) You must cause the modified files to carry prominent notices
X    stating that you changed the files and the date of any change.
X
X    b) You must cause any work that you distribute or publish, that in
X    whole or in part contains or is derived from the Program or any
X    part thereof, to be licensed as a whole at no charge to all third
X    parties under the terms of this License.
X
X    c) If the modified program normally reads commands interactively
X    when run, you must cause it, when started running for such
X    interactive use in the most ordinary way, to print or display an
X    announcement including an appropriate copyright notice and a
X    notice that there is no warranty (or else, saying that you provide
X    a warranty) and that users may redistribute the program under
X    these conditions, and telling the user how to view a copy of this
X    License.  (Exception: if the Program itself is interactive but
X    does not normally print such an announcement, your work based on
X    the Program is not required to print an announcement.)
X
These requirements apply to the modified work as a whole.  If
identifiable sections of that work are not derived from the Program,
and can be reasonably considered independent and separate works in
themselves, then this License, and its terms, do not apply to those
sections when you distribute them as separate works.  But when you
distribute the same sections as part of a whole which is a work based
on the Program, the distribution of the whole must be on the terms of
this License, whose permissions for other licensees extend to the
entire whole, and thus to each and every part regardless of who wrote it.
X
Thus, it is not the intent of this section to claim rights or contest
your rights to work written entirely by you; rather, the intent is to
exercise the right to control the distribution of derivative or
collective works based on the Program.
X
In addition, mere aggregation of another work not based on the Program
with the Program (or with a work based on the Program) on a volume of
a storage or distribution medium does not bring the other work under
the scope of this License.
X
X  3. You may copy and distribute the Program (or a work based on it,
under Section 2) in object code or executable form under the terms of
Sections 1 and 2 above provided that you also do one of the following:
X
X    a) Accompany it with the complete corresponding machine-readable
X    source code, which must be distributed under the terms of Sections
X    1 and 2 above on a medium customarily used for software interchange; or,
X
X    b) Accompany it with a written offer, valid for at least three
X    years, to give any third party, for a charge no more than your
X    cost of physically performing source distribution, a complete
X    machine-readable copy of the corresponding source code, to be
X    distributed under the terms of Sections 1 and 2 above on a medium
X    customarily used for software interchange; or,
X
X    c) Accompany it with the information you received as to the offer
X    to distribute corresponding source code.  (This alternative is
X    allowed only for noncommercial distribution and only if you
X    received the program in object code or executable form with such
X    an offer, in accord with Subsection b above.)
X
The source code for a work means the preferred form of the work for
making modifications to it.  For an executable work, complete source
code means all the source code for all modules it contains, plus any
associated interface definition files, plus the scripts used to
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anything that is normally distributed (in either source or binary
form) with the major components (compiler, kernel, and so on) of the
operating system on which the executable runs, unless that component
itself accompanies the executable.
X
If distribution of executable or object code is made by offering
access to copy from a designated place, then offering equivalent
access to copy the source code from the same place counts as
distribution of the source code, even though third parties are not
compelled to copy the source along with the object code.
X
X  4. You may not copy, modify, sublicense, or distribute the Program
except as expressly provided under this License.  Any attempt
otherwise to copy, modify, sublicense or distribute the Program is
void, and will automatically terminate your rights under this License.
However, parties who have received copies, or rights, from you under
this License will not have their licenses terminated so long as such
parties remain in full compliance.
X
X  5. You are not required to accept this License, since you have not
signed it.  However, nothing else grants you permission to modify or
distribute the Program or its derivative works.  These actions are
prohibited by law if you do not accept this License.  Therefore, by
modifying or distributing the Program (or any work based on the
Program), you indicate your acceptance of this License to do so, and
all its terms and conditions for copying, distributing or modifying
the Program or works based on it.
X
X  6. Each time you redistribute the Program (or any work based on the
Program), the recipient automatically receives a license from the
original licensor to copy, distribute or modify the Program subject to
these terms and conditions.  You may not impose any further
restrictions on the recipients' exercise of the rights granted herein.
You are not responsible for enforcing compliance by third parties to
this License.
X
X  7. If, as a consequence of a court judgment or allegation of patent
infringement or for any other reason (not limited to patent issues),
conditions are imposed on you (whether by court order, agreement or
otherwise) that contradict the conditions of this License, they do not
excuse you from the conditions of this License.  If you cannot
distribute so as to satisfy simultaneously your obligations under this
License and any other pertinent obligations, then as a consequence you
may not distribute the Program at all.  For example, if a patent
license would not permit royalty-free redistribution of the Program by
all those who receive copies directly or indirectly through you, then
the only way you could satisfy both it and this License would be to
refrain entirely from distribution of the Program.
X
If any portion of this section is held invalid or unenforceable under
any particular circumstance, the balance of the section is intended to
apply and the section as a whole is intended to apply in other
circumstances.
X
It is not the purpose of this section to induce you to infringe any
patents or other property right claims or to contest validity of any
such claims; this section has the sole purpose of protecting the
integrity of the free software distribution system, which is
implemented by public license practices.  Many people have made
generous contributions to the wide range of software distributed
through that system in reliance on consistent application of that
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to distribute software through any other system and a licensee cannot
impose that choice.
X
This section is intended to make thoroughly clear what is believed to
be a consequence of the rest of this License.
X
X  8. If the distribution and/or use of the Program is restricted in
certain countries either by patents or by copyrighted interfaces, the
original copyright holder who places the Program under this License
may add an explicit geographical distribution limitation excluding
those countries, so that distribution is permitted only in or among
countries not thus excluded.  In such case, this License incorporates
the limitation as if written in the body of this License.
X
X  9. The Free Software Foundation may publish revised and/or new versions
of the General Public License from time to time.  Such new versions will
be similar in spirit to the present version, but may differ in detail to
address new problems or concerns.
X
XEach version is given a distinguishing version number.  If the Program
specifies a version number of this License which applies to it and "any
later version", you have the option of following the terms and conditions
either of that version or of any later version published by the Free
Software Foundation.  If the Program does not specify a version number of
this License, you may choose any version ever published by the Free Software
XFoundation.
X
X  10. If you wish to incorporate parts of the Program into other free
programs whose distribution conditions are different, write to the author
to ask for permission.  For software which is copyrighted by the Free
Software Foundation, write to the Free Software Foundation; we sometimes
make exceptions for this.  Our decision will be guided by the two goals
of preserving the free status of all derivatives of our free software and
of promoting the sharing and reuse of software generally.
X
X                NO WARRANTY
X
X  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
XFOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
REPAIR OR CORRECTION.
X
X  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.
X
X             END OF TERMS AND CONDITIONS
X
X    Appendix: How to Apply These Terms to Your New Programs
X
X  If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.
X
X  To do so, attach the following notices to the program.  It is safest
to attach them to the start of each source file to most effectively
convey the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.
X
X    <one line to give the program's name and a brief idea of what it does.>
X    Copyright (C) 19yy  <name of author>
X
X    This program is free software; you can redistribute it and/or modify
X    it under the terms of the GNU General Public License as published by
X    the Free Software Foundation; either version 2 of the License, or
X    (at your option) any later version.
X
X    This program is distributed in the hope that it will be useful,
X    but WITHOUT ANY WARRANTY; without even the implied warranty of
X    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
X    GNU General Public License for more details.
X
X    You should have received a copy of the GNU General Public License
X    along with this program; if not, write to the Free Software
X    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
X
Also add information on how to contact you by electronic and paper mail.
X
If the program is interactive, make it output a short notice like this
when it starts in an interactive mode:
X
X    Gnomovision version 69, Copyright (C) 19yy name of author
X    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
X    This is free software, and you are welcome to redistribute it
X    under certain conditions; type `show c' for details.
X
The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License.  Of course, the commands you use may
be called something other than `show w' and `show c'; they could even be
mouse-clicks or menu items--whatever suits your program.
X
You should also get your employer (if you work as a programmer) or your
school, if any, to sign a "copyright disclaimer" for the program, if
necessary.  Here is a sample; alter the names:
X
X  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
X  `Gnomovision' (which makes passes at compilers) written by James Hacker.
X
X  <signature of Ty Coon>, 1 April 1989
X  Ty Coon, President of Vice
X
This General Public License does not permit incorporating your program into
proprietary programs.  If your program is a subroutine library, you may
consider it more useful to permit linking proprietary applications with the
library.  If this is what you want to do, use the GNU Library General
Public License instead of this License.
END_OF_FILE
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    echo shar: \"'admin/gnu2.txt'\" unpacked with wrong size!
fi
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if test -f 'answers/ex16.tex' -a "${1}" != "-c" ; then
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X
X%*******************************************************************************
X%*                    START OF AUTOMATICALLY GENERATED TEX FILE                *
X%*******************************************************************************
X%*                                                                             *
X%* This TeX file was automatically generated by the FunnelWeb preprocessor.    *
X%* You can typeset this file to produce printed documentation by running it    *
X%* through the TeX typesetter using a command such as:                         *
X%*    tex thisfilename                                                         *
X%* The resultant file thisfilename.dvi can be printed using a command such as: *
X%*    lpr -Pcslw -d thisfilename.dvi                                           *
X%*                                                                             *
X%* FunnelWeb is a preprocessor that allows programmers to weave programs and   *
X%* their documentation together in a single document. The FunnelWeb program    *
X%* analyses such documents producing both program files and typeset            *
X%* documentation such as this TeX file.                                        *
X%* FunnelWeb was created by Ross Williams.                                     *
X%*                                                                             *
X%* For more information on FunnelWeb look in the following FTP archive:        *
X%*    Machine  : sirius.itd.adelaide.edu.au [IP=129.127.40.3].                 *
X%*    Directory: ~pub/funnelweb/                                               *
X%*               (or some other appropriately named directory).                *
X%* or email Ross Williams at [e-mail]                         *
X%*                                                                             *
X%*******************************************************************************
X
X
X%===================== Start of FunnelWeb TeX Definitions ======================
X
X
X% Version
X% -------
X% This is FunnelWeb TeX Macro Library Version 1.0.
X
X
X% Copyright
X% ---------
X% This set of FunnelWeb TeX definitions was written by Ross Williams and was
X% originally Copyright (C) 1992 Ross N. Williams.  However, I, Ross Williams,
X% hereby forego any claim to Copyright in this set of FunnelWeb TeX definitions
X% and hereby authorize that the set of TeX definitions pass into the public
X% domain. -- Ross N. Williams, 3:41pm 07-May-1992, Adelaide, Australia.
X
X
X% Modification
X% ------------
X% Please record all modifications to these TeX definitions here. Unless
X% otherwise specified, all modified definitions fall in the public domain too.
X%
X% Programmers:
X%    RNW  Ross N. Williams  [e-mail]
X%
X% Changes:
X%    07-May-1992  RNW  Prepared this work for public domain release.
X%
X
X
X% General Comments
X% ----------------
X% This set of TeX definitions exists for two reasons:
X%
X%    1. To shorten and neaten the FunnelWeb TeX output.
X%    2. To allow users to fiddle with the output format in their input files
X%       (by inserting redefining "\def"s) without having to resort to
X%       modifying the FunnelWeb code.
X%
X% The user is warned that these definitions may be changed from time to time
X% (but probably not much). The user should not be too sneaky. In particular,
X% users wishing to redefine some of these macros should do so in an explicitly
X% defined section at the top of their input file. This will mean that in the
X% event of problems, that section can simply be deleted or commented out to
X% allow the document to at least be typeset in the default format. Users should
X% limit themselves to redefining these macros in such a section and should
X% refrain from using the macros throughout their documents.
X
X
X% Environment Parameters
X% ----------------------
X% \tolerance tells TeX how tolerant it should be about making bad line and
X% page breaks. Here we set it to it's maximum, as
X%   1) Computer programs are likely to cause lots of bad breaks.
X%   2) In most cases the user would probably rather get the TeX file through
X%      TeX without any errors than fiddle with spacings for perfection.
X\tolerance=10000
X
X% I don't like indentation as it makes the page look more busy. Instead,
X% paragraphs are separated by a little space (see next).
X\parindent=0pt
X
X% In many cases, users will produce documents with long runs of paragraphs.
X% In order to space out these paragraphs, it is convenient to maintain a
X% prevailing non-zero \parskip (end-of-paragaph skip). The only trouble is
X% that the skip becomes a problem in macro definitions which require no skip
X% and so we have to turn the skip on and off. The following two macros
X% simplify this process.
X\def\fwparskipon{\parskip=\medskipamount}
X\def\fwparskipoff{\parskip=0pt}
X\fwparskipon
X
X% Setting raggedbottom allows TeX to leave a bit of space at the bottom of the
X% page in order to better vertically align the rest of the page (e.g. skips
X% won't stretch as much). It also means that headings are less likely to be
X% isolated at the bottom of the page without any following text.
X\raggedbottom
X
X
X% Fonts
X% -----
X% Most of the typeset output is set in 10pt roman and 10pt tt font.
X% The major extra font needs spring from titles and headings.
X% For portability's sake we use only the following fonts:
X%    cmr10
X%    cmbx10
X%    cmtt10
X% and some enlargements of them. These fonts are all "standard" fonts
X% in Plain TeX. See The TeXbook p.350.
X\font\fwfontnote=cmr7
X
X\font\fwfontnorm=cmr10
X\font\fwfontnorma=cmr10 scaled \magstep1
X\font\fwfontnormb=cmr10 scaled \magstep2
X
X\font\fwfontbold=cmbx10
X\font\fwfontbolda=cmbx10 scaled \magstep1
X\font\fwfontboldb=cmbx10 scaled \magstep2
X\font\fwfontboldc=cmbx10 scaled \magstep3
X\font\fwfontboldd=cmbx10 scaled \magstep4
X
X
X% Macros for Stylistic Details
X% ----------------------------
X% This section contains all the fiddly little macros for setting the details
X% of each macro definition.
X
X% Macro definitions are sandwiched by calls to these macros which can be used
X% to sort out the spacing before and after the macro definition.
X\def\fwbeginmacro{\fwparskipoff\bigskip}
X\def\fwendmacro{\fwparskipon\par}
X
X% These macros deal with the macro name and definition line.
X\def\fwmacroname#1#2{{\sl #1\/}$\lbrack$#2$\rbrack$}
X\def\fwfilename#1#2{{\bf #1}$\lbrack$#2$\rbrack$}
X\def\fwzero#1{{\bf Z}}
X\def\fwmany#1{{\bf M}}
X\def\fwequals{ $\equiv$}
X\def\fwplusequals{ $+\equiv$}
X
X% Now for the actual body of the definition. It looks nice to have the tt
X% code indented a little. Again, we use macros instead of writing direct TeX,
X% so as to allow the user to fiddle this stuff to taste without having to
X% modify the FunnelWeb C code.
X\def\fwodef{\parindent=15pt\vskip0pt$\lbrace$\parindent=20pt}
X\def\fwcdef{$\rbrace$\vskip0pt\parindent=0pt}
X\def\fwoquote{`}
X\def\fwcquote{'}
X\def\fwoparen{$($}
X\def\fwcomma{$,$}
X\def\fwcparen{$)$}
X\def\fwparam#1{$\diamond #1$}
X\def\fwparams#1{$(\diamond #1)$}
X
X% These macros deal with the notes that are appended at the end of each
X% macro definition. Note that even though \fwisafile,\fwusedin, and \fwseealso
X% have the same definition, they are given different names so as to allow the
X% user to redefine these macros to typeset each kind of information differently
X% if desired.
X\def\fwbeginmacronotes{\begingroup\baselineskip=9pt\smallskip}
X\def\fwnote#1{{\fwfontnote #1}\par}
X\def\fwisafile#1{\fwnote{#1}}
X\def\fwusedin#1{\fwnote{#1}}
X\def\fwseealso#1{\fwnote{#1}}
X\def\fwendmacronotes{\endgroup}
X
X
X% Macros to Typeset Program Code Verbatim
X% ---------------------------------------
X% This is by far the hairiest and most difficult part of the typesetting task
X% because we have to turn off most of TeX's natural instincts in order to
X% typeset the program text exactly as it appears in the input file.
X% Two macros are defined to pull this off: \fwbtx and \fwverbatimgobble.
X% Their code was inspired by the following sections of "The TeXbook":
X%    Appendix D: Dirty Tricks, 3.Verbatim listing, p.380-382.
X%    Appendix E: Example Formats, p.421.
X% The \fwbtx[ (for "FunnelWeb Begin TeXt") macro does most of the hard work.
X% The liberal use of "%" is because I don't understand TeX well enough to
X% understand when an end of line will cause trouble, and I am playing it safe.
X
X% Before defining the main \fwbtx macro, we have to stash away some definitions
X% in the hidden part of TeX's environment. Let's hope that these "hidden"
X% definitions don't affect anything except what is desired to be affected.
X
X% The tt font in which we wish to set the text has two Latin lurking ligatures!
X% These are ?` and !`. To disable them, we define the left quote when ACTIVE
X% to be defined in such a way as to prevent ligatures. The main TeX text will
X% normally not be exposed to this definition because normally the leftquote
X% character is not active. The \fwbtx macro temporarily makes the left quote
X% character active thus activating the deactivation of left quote ligatures.
X% See The TeXbook p.381.
X{\catcode`\`=\active \gdef`{\relax\lq}}
X
X% TeX is fairly carefree about spaces and so we have to make it more serious.
X% To do so we pull the same trick as above, setting up a definition for active
X% space, but only making space active during the span of the verbatim text.
X% In Plain TeX the active space is defined to be simply a space, but here we
X% define it to be a control space. This ensures that the space cannot
X% be gobbled up by one of TeX's mysterious mechanisms when activated.
X% See The TeXbook, p.381 and p.352.
X{\obeyspaces\global\let =\ }
X
X% Here is the main \fwbtx verbatim text macro.
X% Note: The order in which all these pieces of business have to be done is
X% still a partial mystery to me. Don't fiddle with this stuff unless you
X% think you know what you are doing.
X\def\fwbtx[{%
X%
X% The funnies involved in getting verbatim output are safely housed inside
X% this \begingroup, and the \endgroup in \fwverbatimgobble. Groups are used
X% instead of curly braces because we have to be able to signal the end of
X% this macro with a curly brace.
X\begingroup%
X%
X% \pars at the end of empty lines in the verbatim text won't come out normally
X% because TeX is in vertical mode and they get gobbled up. To prevent this,
X% we force \par to exit vertical mode first. See The TeXbook p.381.
X\def\par{\leavevmode\endgraf}%
X%
X% Activate the leftquote character so as to avoid ligatures (see above).
X\catcode`\`=\active%
X%
X% The \obeylines macro simply defines end of line (^M) to be \par. This ensures
X% that TeX will treat each verbatim line as a new paragraph.
X\obeylines%
X%
X% To get verbatim output, we have to desex all the special characters. This
X% is explained in detail in The TeXbook p.380.
X\def\do##1{\catcode`##1=12 }\dospecials%
X%
X% Activate the space character so as to make TeX treat blanks seriously.
X% This activation invokes an eralier definition (see above).
X\obeyspaces
X%
X% Interparagraph skips do not help the cause.
X% Note: We have to preserve the indentation though, as the code is actually
X% indented in the final output. See \fwodef in an earlier section.
X\parskip=0pt%
X%
X% We typeset the verbatim text in tt font (courier on the Macintosh) for a
X% number of reasons:
X%    - tt font has the same horizontal spacing for each character.
X%    - tt font covers the ASCII character set.
X%    - tt font doesn't have many surprises (e.g. ligatures).
X%    - tt font looks much what you might see on a computer terminal screen.
X\tt%
X%
X% Having set up an environment for verbatim, we are ready to use it.
X% By invoking \fwverbatimgobble, this \fwbtx macro gobbles up text verbatim (as
X% part of the parameter of \fwverbatimgobble) until it sees the termination
X% string "]fwetx=" (the "=" was thrown in to add obscurity as this sequence
X% must never occur in the verbatim text).
X\fwverbatimgobble}
X
X% The \fwverbatimgobble macro exists to allow \fwbtx to bracket verbatim text.
X\def\fwverbatimgobble#1]fwetx={#1\endgroup}
X
X
X% Table of Contents
X% -----------------
X% The five levels of table of contents that FunnelWeb supports are identified
X% by the five letters [A..E]. These are used throughout the following macros.
X
X% The following macros are utilities to the TOC macros to follow.
X\def\fwrule{\medskip\hrule\medskip}
X\def\fwqh{\hskip1.5em\relax}
X\def\fwbeforesec{\penalty-200\bigskip\medskip\par}
X
X% The following macros are used to typeset the table of contents.
X\def\fwtocstart#1{\fwrule\leftline{\fwfontbolda Table of Contents}\fwrule}
X\def\fwtoca#1#2{\leftline{{\bf #1 #2}}}
X\def\fwtocb#1#2{\leftline{\fwqh #1 #2}}
X\def\fwtocc#1#2{\leftline{\fwqh\fwqh #1 #2}}
X\def\fwtocd#1#2{\leftline{\fwqh\fwqh\fwqh #1 #2}}
X\def\fwtoce#1#2{\leftline{\fwqh\fwqh\fwqh\fwqh #1 #2}}
X\def\fwtocfinish#1{\fwrule}
X
X% The following "library" macros define five different strengths of headings
X% which can be used later in the section macros.
X\def\fwliba#1#2{\vfill\eject{\fwfontboldc #1 #2}\penalty200\smallskip}
X\def\fwlibb#1#2{\fwbeforesec{\fwfontboldb #1 #2}\penalty200\smallskip}
X\def\fwlibc#1#2{\fwbeforesec{\fwfontnormb #1 #2}\penalty200\smallskip}
X\def\fwlibd#1#2{\fwbeforesec{\bf          #1 #2}\penalty200}
X\def\fwlibe#1#2{\fwbeforesec{\bf          #1 #2}}
X
X% Here are the macros that actually typeset the section headings throughout
X% the document. The fwlib system has been employed so as to easily allow the
X% user to redefine the strengths of headings to taste. For example, the
X% user could insert in the input document a similar set of definitions to these
X% but with the b..e headings set to \fwlibc. This would tone down the output.
X\def\fwseca#1#2{\fwliba{#1}{#2}}
X\def\fwsecb#1#2{\fwlibb{#1}{#2}}
X\def\fwsecc#1#2{\fwlibc{#1}{#2}}
X\def\fwsecd#1#2{\fwlibd{#1}{#2}}
X\def\fwsece#1#2{\fwlibe{#1}{#2}}
X
X
X% Support for Explicit Typesetting
X% --------------------------------
X% FunnelWeb supports pragmas and other constructs that allow
X% typesetter-independent typesetting commands to be given. The
X% following macros support these features.
X
X% The in-text literal @{sloth@} and emphasise @[walrus@] features.
X\def\fwlit#1{{\tt #1}}
X\def\fwemp#1{{\it #1}}
X
X% The "@p new_page" pragma.
X\def\fwnewpage{\vfill\eject}
X
X% The "@p vskip Nmm" pragma.
X\def\fwvskip#1{\null\vskip #1mm}
X
X% The "@p title <font> <align> <text>" pragma.
X\def\fwfontnormal#1{{\fwfontnorm {#1}}}
X\def\fwfonttitle#1{{\fwfontboldd {#1}}}
X\def\fwfontsmalltitle#1{{\fwfontboldb {#1}}}
X\def\fwleftline#1{\leftline{#1}}
X\def\fwcenterline#1{\centerline{#1}}
X\def\fwrightline#1{\rightline{#1}}
X
X
X% Support for Old FunnelWeb
X% -------------------------
X% The following macros were used extensively in the first version of
X% FunnelWeb and are retained so that these older input files will still
X% typeset cleanly.
X\def\p#1{{\tt #1}}  % P for Program text.
X\def\flagpage#1#2{
X   \null
X   \vfill
X   \centerline{\fwfontboldd #1}
X   \vskip 1cm
X   \centerline{\fwfontboldd #2}
X   \vfill
X   \null
X   \vfill
X}
X
X%====================== End of FunnelWeb TeX Definitions =======================
X
X\fwvskip{40}
X\fwcenterline{\fwfonttitle{Powers:}}
X\fwcenterline{\fwfonttitle{An Example of}}
X\fwcenterline{\fwfonttitle{A Short}}
X\fwcenterline{\fwfonttitle{FunnelWeb .fw File}}
X\fwvskip{10}
X\fwcenterline{\fwfontsmalltitle{by Ross Williams}}
X\fwcenterline{\fwfontsmalltitle{26 January 1992}}
X\fwvskip{20}
X
X\fwtocstart{}
X\fwtoca{1}{FunnelWeb Example Program}
X\fwtocb{1.1}{ex16.out}
X\fwtocb{1.2}{Pull in packages}
X\fwtocb{1.3}{Write out the first p powers of i on a single line}
X\fwtocfinish{}
X
X
X\fwseca{1}{FunnelWeb Example Program}
X
This  program writes  out each  of the  first \fwlit{p}  powers of  the first  \fwlit{n}
integers. These  constant parameters are located  here so that they  are easy to
change.
X
X\fwbeginmacro
X\fwmacroname{Constants}{1}\fwequals \fwodef \fwbtx[n : constant natural := 10;     -- How many numbers? (Ans: [1,n]).
p : constant natural :=  5;     -- How many powers?  (Ans: [1,p]).]fwetx=%
X\fwcdef
X\fwbeginmacronotes
X\fwusedin{This macro is invoked in definition 2.}
X\fwendmacronotes
X\fwendmacro
X
X
X\fwsecb{1.1}{ex16.out} Here is  the outline of the  program. This FunnelWeb file  generates a single
Ada output file  called \fwlit{Power.ada}. The main program consists  of a loop that
iterates once for each number to be written out.
X
X\fwbeginmacro
X\fwfilename{ex16.out}{2}\fwequals \fwodef \fwmacroname{Pull in packages}{3}\fwbtx[
X
procedure example is
X   ]fwetx=%
X\fwmacroname{Constants}{1}\fwbtx[
begin -- example
X   for i in 1..n loop
X      ]fwetx=%
X\fwmacroname{Write out the first p powers of i on a single line}{4}\fwbtx[
X   end loop;
end example;
X]fwetx=%
X\fwcdef
X\fwbeginmacronotes
X\fwisafile{This macro is attached to an output file.}
X\fwendmacronotes
X\fwendmacro
X
X
X\fwsecb{1.2}{Pull in packages} In this section,  we pull in the packages that this program  needs to run. In
fact, all we need is the IO package so that we can write out the results. To use
the IO package, we first of all need  to haul it in (\fwlit{with text\_io}) and then
we need to make all its identifiers visible at the top level (\fwlit{use text\_io}).
X
X\fwbeginmacro
X\fwmacroname{Pull in packages}{3}\fwequals \fwodef \fwbtx[with text_io; use text_io;]fwetx=%
X\fwcdef
X\fwbeginmacronotes
X\fwusedin{This macro is invoked in definition 2.}
X\fwendmacronotes
X\fwendmacro
X
X
X\fwsecb{1.3}{Write out the first p powers of i on a single line} Here is  the bit that writes out  the first \fwlit{p} powers of  \fwlit{i}. The power
values  are  calculated  incrementally  in  \fwlit{ip}  to  avoid  the  use  of  the
exponentiation operator.
X
X\fwbeginmacro
X\fwmacroname{Write out the first p powers of i on a single line}{4}\fwequals \fwodef \fwbtx[declare
X   ip : natural := 1;
begin
X   for power in 1..p loop
X      ip:=ip*i;
X      put(natural'image(ip) & " ");
X   end loop;
X   new_line;
end;]fwetx=%
X\fwcdef
X\fwbeginmacronotes
X\fwusedin{This macro is invoked in definition 2.}
X\fwendmacronotes
X\fwendmacro
X
X
X\bye
X
X
X%*******************************************************************************
X%*                    END OF AUTOMATICALLY GENERATED TEX FILE                  *
X%*******************************************************************************
X
END_OF_FILE
if test 18160 -ne `wc -c <'answers/ex16.tex'`; then
    echo shar: \"'answers/ex16.tex'\" unpacked with wrong size!
fi
# end of 'answers/ex16.tex'
fi
if test -f 'answers/wv02.tex' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'answers/wv02.tex'\"
else
echo shar: Extracting \"'answers/wv02.tex'\" \(17380 characters\)
sed "s/^X//" >'answers/wv02.tex' <<'END_OF_FILE'
X
X%*******************************************************************************
X%*                    START OF AUTOMATICALLY GENERATED TEX FILE                *
X%*******************************************************************************
X%*                                                                             *
X%* This TeX file was automatically generated by the FunnelWeb preprocessor.    *
X%* You can typeset this file to produce printed documentation by running it    *
X%* through the TeX typesetter using a command such as:                         *
X%*    tex thisfilename                                                         *
X%* The resultant file thisfilename.dvi can be printed using a command such as: *
X%*    lpr -Pcslw -d thisfilename.dvi                                           *
X%*                                                                             *
X%* FunnelWeb is a preprocessor that allows programmers to weave programs and   *
X%* their documentation together in a single document. The FunnelWeb program    *
X%* analyses such documents producing both program files and typeset            *
X%* documentation such as this TeX file.                                        *
X%* FunnelWeb was created by Ross Williams.                                     *
X%*                                                                             *
X%* For more information on FunnelWeb look in the following FTP archive:        *
X%*    Machine  : sirius.itd.adelaide.edu.au [IP=129.127.40.3].                 *
X%*    Directory: ~pub/funnelweb/                                               *
X%*               (or some other appropriately named directory).                *
X%* or email Ross Williams at [e-mail]                         *
X%*                                                                             *
X%*******************************************************************************
X
X
X%===================== Start of FunnelWeb TeX Definitions ======================
X
X
X% Version
X% -------
X% This is FunnelWeb TeX Macro Library Version 1.0.
X
X
X% Copyright
X% ---------
X% This set of FunnelWeb TeX definitions was written by Ross Williams and was
X% originally Copyright (C) 1992 Ross N. Williams.  However, I, Ross Williams,
X% hereby forego any claim to Copyright in this set of FunnelWeb TeX definitions
X% and hereby authorize that the set of TeX definitions pass into the public
X% domain. -- Ross N. Williams, 3:41pm 07-May-1992, Adelaide, Australia.
X
X
X% Modification
X% ------------
X% Please record all modifications to these TeX definitions here. Unless
X% otherwise specified, all modified definitions fall in the public domain too.
X%
X% Programmers:
X%    RNW  Ross N. Williams  [e-mail]
X%
X% Changes:
X%    07-May-1992  RNW  Prepared this work for public domain release.
X%
X
X
X% General Comments
X% ----------------
X% This set of TeX definitions exists for two reasons:
X%
X%    1. To shorten and neaten the FunnelWeb TeX output.
X%    2. To allow users to fiddle with the output format in their input files
X%       (by inserting redefining "\def"s) without having to resort to
X%       modifying the FunnelWeb code.
X%
X% The user is warned that these definitions may be changed from time to time
X% (but probably not much). The user should not be too sneaky. In particular,
X% users wishing to redefine some of these macros should do so in an explicitly
X% defined section at the top of their input file. This will mean that in the
X% event of problems, that section can simply be deleted or commented out to
X% allow the document to at least be typeset in the default format. Users should
X% limit themselves to redefining these macros in such a section and should
X% refrain from using the macros throughout their documents.
X
X
X% Environment Parameters
X% ----------------------
X% \tolerance tells TeX how tolerant it should be about making bad line and
X% page breaks. Here we set it to it's maximum, as
X%   1) Computer programs are likely to cause lots of bad breaks.
X%   2) In most cases the user would probably rather get the TeX file through
X%      TeX without any errors than fiddle with spacings for perfection.
X\tolerance=10000
X
X% I don't like indentation as it makes the page look more busy. Instead,
X% paragraphs are separated by a little space (see next).
X\parindent=0pt
X
X% In many cases, users will produce documents with long runs of paragraphs.
X% In order to space out these paragraphs, it is convenient to maintain a
X% prevailing non-zero \parskip (end-of-paragaph skip). The only trouble is
X% that the skip becomes a problem in macro definitions which require no skip
X% and so we have to turn the skip on and off. The following two macros
X% simplify this process.
X\def\fwparskipon{\parskip=\medskipamount}
X\def\fwparskipoff{\parskip=0pt}
X\fwparskipon
X
X% Setting raggedbottom allows TeX to leave a bit of space at the bottom of the
X% page in order to better vertically align the rest of the page (e.g. skips
X% won't stretch as much). It also means that headings are less likely to be
X% isolated at the bottom of the page without any following text.
X\raggedbottom
X
X
X% Fonts
X% -----
X% Most of the typeset output is set in 10pt roman and 10pt tt font.
X% The major extra font needs spring from titles and headings.
X% For portability's sake we use only the following fonts:
X%    cmr10
X%    cmbx10
X%    cmtt10
X% and some enlargements of them. These fonts are all "standard" fonts
X% in Plain TeX. See The TeXbook p.350.
X\font\fwfontnote=cmr7
X
X\font\fwfontnorm=cmr10
X\font\fwfontnorma=cmr10 scaled \magstep1
X\font\fwfontnormb=cmr10 scaled \magstep2
X
X\font\fwfontbold=cmbx10
X\font\fwfontbolda=cmbx10 scaled \magstep1
X\font\fwfontboldb=cmbx10 scaled \magstep2
X\font\fwfontboldc=cmbx10 scaled \magstep3
X\font\fwfontboldd=cmbx10 scaled \magstep4
X
X
X% Macros for Stylistic Details
X% ----------------------------
X% This section contains all the fiddly little macros for setting the details
X% of each macro definition.
X
X% Macro definitions are sandwiched by calls to these macros which can be used
X% to sort out the spacing before and after the macro definition.
X\def\fwbeginmacro{\fwparskipoff\bigskip}
X\def\fwendmacro{\fwparskipon\par}
X
X% These macros deal with the macro name and definition line.
X\def\fwmacroname#1#2{{\sl #1\/}$\lbrack$#2$\rbrack$}
X\def\fwfilename#1#2{{\bf #1}$\lbrack$#2$\rbrack$}
X\def\fwzero#1{{\bf Z}}
X\def\fwmany#1{{\bf M}}
X\def\fwequals{ $\equiv$}
X\def\fwplusequals{ $+\equiv$}
X
X% Now for the actual body of the definition. It looks nice to have the tt
X% code indented a little. Again, we use macros instead of writing direct TeX,
X% so as to allow the user to fiddle this stuff to taste without having to
X% modify the FunnelWeb C code.
X\def\fwodef{\parindent=15pt\vskip0pt$\lbrace$\parindent=20pt}
X\def\fwcdef{$\rbrace$\vskip0pt\parindent=0pt}
X\def\fwoquote{`}
X\def\fwcquote{'}
X\def\fwoparen{$($}
X\def\fwcomma{$,$}
X\def\fwcparen{$)$}
X\def\fwparam#1{$\diamond #1$}
X\def\fwparams#1{$(\diamond #1)$}
X
X% These macros deal with the notes that are appended at the end of each
X% macro definition. Note that even though \fwisafile,\fwusedin, and \fwseealso
X% have the same definition, they are given different names so as to allow the
X% user to redefine these macros to typeset each kind of information differently
X% if desired.
X\def\fwbeginmacronotes{\begingroup\baselineskip=9pt\smallskip}
X\def\fwnote#1{{\fwfontnote #1}\par}
X\def\fwisafile#1{\fwnote{#1}}
X\def\fwusedin#1{\fwnote{#1}}
X\def\fwseealso#1{\fwnote{#1}}
X\def\fwendmacronotes{\endgroup}
X
X
X% Macros to Typeset Program Code Verbatim
X% ---------------------------------------
X% This is by far the hairiest and most difficult part of the typesetting task
X% because we have to turn off most of TeX's natural instincts in order to
X% typeset the program text exactly as it appears in the input file.
X% Two macros are defined to pull this off: \fwbtx and \fwverbatimgobble.
X% Their code was inspired by the following sections of "The TeXbook":
X%    Appendix D: Dirty Tricks, 3.Verbatim listing, p.380-382.
X%    Appendix E: Example Formats, p.421.
X% The \fwbtx[ (for "FunnelWeb Begin TeXt") macro does most of the hard work.
X% The liberal use of "%" is because I don't understand TeX well enough to
X% understand when an end of line will cause trouble, and I am playing it safe.
X
X% Before defining the main \fwbtx macro, we have to stash away some definitions
X% in the hidden part of TeX's environment. Let's hope that these "hidden"
X% definitions don't affect anything except what is desired to be affected.
X
X% The tt font in which we wish to set the text has two Latin lurking ligatures!
X% These are ?` and !`. To disable them, we define the left quote when ACTIVE
X% to be defined in such a way as to prevent ligatures. The main TeX text will
X% normally not be exposed to this definition because normally the leftquote
X% character is not active. The \fwbtx macro temporarily makes the left quote
X% character active thus activating the deactivation of left quote ligatures.
X% See The TeXbook p.381.
X{\catcode`\`=\active \gdef`{\relax\lq}}
X
X% TeX is fairly carefree about spaces and so we have to make it more serious.
X% To do so we pull the same trick as above, setting up a definition for active
X% space, but only making space active during the span of the verbatim text.
X% In Plain TeX the active space is defined to be simply a space, but here we
X% define it to be a control space. This ensures that the space cannot
X% be gobbled up by one of TeX's mysterious mechanisms when activated.
X% See The TeXbook, p.381 and p.352.
X{\obeyspaces\global\let =\ }
X
X% Here is the main \fwbtx verbatim text macro.
X% Note: The order in which all these pieces of business have to be done is
X% still a partial mystery to me. Don't fiddle with this stuff unless you
X% think you know what you are doing.
X\def\fwbtx[{%
X%
X% The funnies involved in getting verbatim output are safely housed inside
X% this \begingroup, and the \endgroup in \fwverbatimgobble. Groups are used
X% instead of curly braces because we have to be able to signal the end of
X% this macro with a curly brace.
X\begingroup%
X%
X% \pars at the end of empty lines in the verbatim text won't come out normally
X% because TeX is in vertical mode and they get gobbled up. To prevent this,
X% we force \par to exit vertical mode first. See The TeXbook p.381.
X\def\par{\leavevmode\endgraf}%
X%
X% Activate the leftquote character so as to avoid ligatures (see above).
X\catcode`\`=\active%
X%
X% The \obeylines macro simply defines end of line (^M) to be \par. This ensures
X% that TeX will treat each verbatim line as a new paragraph.
X\obeylines%
X%
X% To get verbatim output, we have to desex all the special characters. This
X% is explained in detail in The TeXbook p.380.
X\def\do##1{\catcode`##1=12 }\dospecials%
X%
X% Activate the space character so as to make TeX treat blanks seriously.
X% This activation invokes an eralier definition (see above).
X\obeyspaces
X%
X% Interparagraph skips do not help the cause.
X% Note: We have to preserve the indentation though, as the code is actually
X% indented in the final output. See \fwodef in an earlier section.
X\parskip=0pt%
X%
X% We typeset the verbatim text in tt font (courier on the Macintosh) for a
X% number of reasons:
X%    - tt font has the same horizontal spacing for each character.
X%    - tt font covers the ASCII character set.
X%    - tt font doesn't have many surprises (e.g. ligatures).
X%    - tt font looks much what you might see on a computer terminal screen.
X\tt%
X%
X% Having set up an environment for verbatim, we are ready to use it.
X% By invoking \fwverbatimgobble, this \fwbtx macro gobbles up text verbatim (as
X% part of the parameter of \fwverbatimgobble) until it sees the termination
X% string "]fwetx=" (the "=" was thrown in to add obscurity as this sequence
X% must never occur in the verbatim text).
X\fwverbatimgobble}
X
X% The \fwverbatimgobble macro exists to allow \fwbtx to bracket verbatim text.
X\def\fwverbatimgobble#1]fwetx={#1\endgroup}
X
X
X% Table of Contents
X% -----------------
X% The five levels of table of contents that FunnelWeb supports are identified
X% by the five letters [A..E]. These are used throughout the following macros.
X
X% The following macros are utilities to the TOC macros to follow.
X\def\fwrule{\medskip\hrule\medskip}
X\def\fwqh{\hskip1.5em\relax}
X\def\fwbeforesec{\penalty-200\bigskip\medskip\par}
X
X% The following macros are used to typeset the table of contents.
X\def\fwtocstart#1{\fwrule\leftline{\fwfontbolda Table of Contents}\fwrule}
X\def\fwtoca#1#2{\leftline{{\bf #1 #2}}}
X\def\fwtocb#1#2{\leftline{\fwqh #1 #2}}
X\def\fwtocc#1#2{\leftline{\fwqh\fwqh #1 #2}}
X\def\fwtocd#1#2{\leftline{\fwqh\fwqh\fwqh #1 #2}}
X\def\fwtoce#1#2{\leftline{\fwqh\fwqh\fwqh\fwqh #1 #2}}
X\def\fwtocfinish#1{\fwrule}
X
X% The following "library" macros define five different strengths of headings
X% which can be used later in the section macros.
X\def\fwliba#1#2{\vfill\eject{\fwfontboldc #1 #2}\penalty200\smallskip}
X\def\fwlibb#1#2{\fwbeforesec{\fwfontboldb #1 #2}\penalty200\smallskip}
X\def\fwlibc#1#2{\fwbeforesec{\fwfontnormb #1 #2}\penalty200\smallskip}
X\def\fwlibd#1#2{\fwbeforesec{\bf          #1 #2}\penalty200}
X\def\fwlibe#1#2{\fwbeforesec{\bf          #1 #2}}
X
X% Here are the macros that actually typeset the section headings throughout
X% the document. The fwlib system has been employed so as to easily allow the
X% user to redefine the strengths of headings to taste. For example, the
X% user could insert in the input document a similar set of definitions to these
X% but with the b..e headings set to \fwlibc. This would tone down the output.
X\def\fwseca#1#2{\fwliba{#1}{#2}}
X\def\fwsecb#1#2{\fwlibb{#1}{#2}}
X\def\fwsecc#1#2{\fwlibc{#1}{#2}}
X\def\fwsecd#1#2{\fwlibd{#1}{#2}}
X\def\fwsece#1#2{\fwlibe{#1}{#2}}
X
X
X% Support for Explicit Typesetting
X% --------------------------------
X% FunnelWeb supports pragmas and other constructs that allow
X% typesetter-independent typesetting commands to be given. The
X% following macros support these features.
X
X% The in-text literal @{sloth@} and emphasise @[walrus@] features.
X\def\fwlit#1{{\tt #1}}
X\def\fwemp#1{{\it #1}}
X
X% The "@p new_page" pragma.
X\def\fwnewpage{\vfill\eject}
X
X% The "@p vskip Nmm" pragma.
X\def\fwvskip#1{\null\vskip #1mm}
X
X% The "@p title <font> <align> <text>" pragma.
X\def\fwfontnormal#1{{\fwfontnorm {#1}}}
X\def\fwfonttitle#1{{\fwfontboldd {#1}}}
X\def\fwfontsmalltitle#1{{\fwfontboldb {#1}}}
X\def\fwleftline#1{\leftline{#1}}
X\def\fwcenterline#1{\centerline{#1}}
X\def\fwrightline#1{\rightline{#1}}
X
X
X% Support for Old FunnelWeb
X% -------------------------
X% The following macros were used extensively in the first version of
X% FunnelWeb and are retained so that these older input files will still
X% typeset cleanly.
X\def\p#1{{\tt #1}}  % P for Program text.
X\def\flagpage#1#2{
X   \null
X   \vfill
X   \centerline{\fwfontboldd #1}
X   \vskip 1cm
X   \centerline{\fwfontboldd #2}
X   \vfill
X   \null
X   \vfill
X}
X
X%====================== End of FunnelWeb TeX Definitions =======================
WV05: Test typesetting features.
X
X\fwbeginmacro
X\fwfilename{wv05.out}{1}\fwequals \fwodef \fwbtx[
X]fwetx=%
X\fwcdef
X\fwbeginmacronotes
X\fwisafile{This macro is attached to an output file.}
X\fwendmacronotes
X\fwendmacro
X
X
X1. Test all five levels of headings with explicit titles.
X
X\fwseca{1}{One}
X\fwsecb{1.1}{Two}
X\fwsecc{1.1.1}{Three}
X\fwsecd{1.1.1.1}{Four}
X\fwsece{1.1.1.1.1}{Five}
X
X2. Test all five levels of headings with implicit titles.
X
X\fwseca{2}{Macro at level one}
X\fwbeginmacro
X\fwmacroname{Macro at level one}{2}\fwzero{}\fwequals \fwodef \fwbtx[Sloth]fwetx=%
X\fwcdef
X\fwbeginmacronotes
X\fwusedin{This macro is NEVER invoked.}
X\fwendmacronotes
X\fwendmacro
X
X
X\fwsecb{2.1}{Macro at level two}
X\fwbeginmacro
X\fwmacroname{Macro at level two}{3}\fwzero{}\fwequals \fwodef \fwbtx[Walrus]fwetx=%
X\fwcdef
X\fwbeginmacronotes
X\fwusedin{This macro is NEVER invoked.}
X\fwendmacronotes
X\fwendmacro
X
X
X\fwsecc{2.1.1}{Macro at level three}
X\fwbeginmacro
X\fwmacroname{Macro at level three}{4}\fwzero{}\fwequals \fwodef \fwbtx[Aardvark]fwetx=%
X\fwcdef
X\fwbeginmacronotes
X\fwusedin{This macro is NEVER invoked.}
X\fwendmacronotes
X\fwendmacro
X
X
X\fwsecd{2.1.1.1}{Macro at level four}
X\fwbeginmacro
X\fwmacroname{Macro at level four}{5}\fwzero{}\fwequals \fwodef \fwbtx[Teapot]fwetx=%
X\fwcdef
X\fwbeginmacronotes
X\fwusedin{This macro is NEVER invoked.}
X\fwendmacronotes
X\fwendmacro
X
X
X\fwsece{2.1.1.1.1}{Macro at level five}
X\fwbeginmacro
X\fwmacroname{Macro at level five}{6}\fwzero{}\fwequals \fwodef \fwbtx[Emu]fwetx=%
X\fwcdef
X\fwbeginmacronotes
X\fwusedin{This macro is NEVER invoked.}
X\fwendmacronotes
X\fwendmacro
X
X
X3. Test the table of contents directive.
X
X\fwtocstart{}
X\fwtoca{1}{One}
X\fwtocb{1.1}{Two}
X\fwtocc{1.1.1}{Three}
X\fwtocd{1.1.1.1}{Four}
X\fwtoce{1.1.1.1.1}{Five}
X\fwtoca{2}{Macro at level one}
X\fwtocb{2.1}{Macro at level two}
X\fwtocc{2.1.1}{Macro at level three}
X\fwtocd{2.1.1.1}{Macro at level four}
X\fwtoce{2.1.1.1.1}{Macro at level five}
X\fwtocfinish{}
X
X
X4. Test the newpage directive.
X
X\fwnewpage
X
X
X5. Test the vskip directive.
X\fwvskip{50}
X
X6. Test the title directive.
X\fwcenterline{\fwfonttitle{This is a test Title}}
X
X
X\bye
X
X
X%*******************************************************************************
X%*                    END OF AUTOMATICALLY GENERATED TEX FILE                  *
X%*******************************************************************************
X
END_OF_FILE
if test 17380 -ne `wc -c <'answers/wv02.tex'`; then
    echo shar: \"'answers/wv02.tex'\" unpacked with wrong size!
fi
# end of 'answers/wv02.tex'
fi
if test -f 'hackman/h_ch2.tex' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'hackman/h_ch2.tex'\"
else
echo shar: Extracting \"'hackman/h_ch2.tex'\" \(18854 characters\)
sed "s/^X//" >'hackman/h_ch2.tex' <<'END_OF_FILE'
X%==============================================================================%
X%                              Start of Ch2.tex                                %
X%==============================================================================%
X%
X% Copyright
X% ---------
X% Copyright (C) 1992 Ross N. Williams.
X% This file contains a chapter of the FunnelWeb Hacker's Manual.
X% See the main TeX file for this manual for further information.
X%
X%==============================================================================%
X
X\chapter{FunnelWeb Implementation}
X\label{chapimplementation}\xx{FunnelWeb}{implementation}
X
X\section{Introduction}
X
This chapter contains notes on the actual C code that implements
XFunnelWeb~V3. This chapter is rather patchy. It has acted mainly as
a dumping ground for ideas that I bothered to write about during
development.
X
X\section{History of FunnelWeb Implementations}
X\xx{FunnelWeb}{history}\x{FunnelWeb version 1}\x{FunnelWeb version 2}%
X\x{FunnelWeb version 3}
X
The first implementation of FunnelWeb (FunnelWeb~V1) was written in
Ada\x{Ada}
in December 1986. The project was initially canned as requiring too
much time, but was resurrected when I decided to commit to
Ada\paper{USDOD83} and
realized that I needed a program to write to help me to learn Ada.
XFunnelWeb~V1 was, in fact, my first Ada program. It took about one
month to write.
X
XFunnelWeb~V1 was used intensively by myself to write Ada programs
from January~1986 to July~1989 at which time
I finished my Ph.D.\x{Ph.D.} and lost access to
the VAX. During this time at least twenty thousand lines of code were generated
using FunnelWeb. Hardly anyone but myself used
XFunnelWeb.\xx{FunnelWeb}{past use}
X
After losing access to Ada and the Vax (and hence to FunnelWeb), I was forced
back to programming the non-literate way. From time to time I found that I
needed to use some of my old programs that I had written using Ada and
XFunnelWeb. I knew that Ada would become available on more machines, but
certainly FunnelWeb wouldn't. I recognised a strong need for a portable
version of FunnelWeb written in~C but didn't have the time or energy
to create one.
X
About this time (late 1989), David Hulse,\xn{David}{Hulse}
at the time a student in
Computer Science at the University of Adelaide,\xx{University}{Adelaide}
volunteered to translate the 4000 line Ada version of FunnelWeb into~C.
To my knowledge this translation process took about three weeks
X(in December 1989). The result was called FunnelWeb~V2 and was
formally signed into the public domain on 5~May 1992.
X
In general, David Hulse did a good job. However, the resultant code
suffered from one or few serious defects, the most serious of which was
a lack of portability.
X
Lack of portability of the C~code, combined with the need for a rather
solid design review, combined with the need to
strengthen the program to bring it up to production standard, resulted
in my performing a complete reworking of the code. The C code was
entirely, but incrementally, replaced or reformatted.
The code was also strengthened and new features were added.
This process took about two months (November and December 1991).
A further two months (approx) were spent writing documentation, constructing
a regression test suite, porting the program to different machines,
and sorting out the legal issues involved in its release.
X
I would like to take this opportunity to record a debt of gratitude to
David Hulse who translated FunnelWeb from Ada to~C. Although my
reworking of his C~code obliterated most of his code,
his translation was pivotal to the development process.
Without his effort in moving from Ada to~C, I'm not sure that I
would have mustered the energy and time to complete the process and
bring FunnelWeb up to its current standard.
X
X\section{Why FunnelWeb Wasn't Used to Write Itself}
X\xx{FunnelWeb}{writing itself}
X
After Knuth created the Web literate preprocessing system, he
re-wrote it using Web and distributed the source code in Web source form.
To allow the Web source code to be tangled by users not yet having a
copy of Web, he also included the tangled Pascal code for the Tangler.
X
While this approach is heroic and serves to convey a commitment and
a confidence in literate programming, it seemed to me that writing FunnelWeb
in FunnelWeb would simply be asking for trouble.\xx{trouble}{asking for}
XFor a start, it would be
very hard to modify any feature of FunnelWeb that had been used to write
XFunnelWeb, and the thought of what would happen if the working executable
became inoperative for some reason does not bear thinking upon.
X
One million billion computer programs were written in the non-literate
style before FunnelWeb was created. Why not one more?
X
X\section{Coding Style}
X\xx{coding}{style}
X
Although FunnelWeb wasn't coded under any particular coding standard,
it was coded in accordance with a fairly strict personal style of C
which developed during the development of FunnelWeb. This style was
subsequently embodied in a real C coding standard prepared for the
South\x{South Australian Government Department of Lands}
Australian Government
Department of Lands.\footnote{The standard
is currently unavailable, but is likely to be released or
published eventually.} Unfortunately, FunnelWeb was not
formally developed under the standard and so some holes remain in
XFunnelWeb's coding style. This section aims to describe some of the more
important aspects of the coding style.
X
X\thing{Portability:} This\x{portability}
was a major goal of the FunnelWeb implementation.
Two excellent books guided this move to portability.
They were \paper{Rabinowitz90} (which deals with C code itself)
and \paper{Horton90} (which deals with the portability of various library
calls). Other works such as \paper{Kernighan88} and
X\paper{ANSI} were also helpful.
X
X\thing{Identifiers:} \paper{Rabinowitz90}\x{identifier}{length}
specifies that for
wide portability, identifiers of block and file scope should be unique to
eight characters, and identifiers of program scope should be unique to
six characters. I have gone further in FunnelWeb and actually made these
restrictions actual limits on identifier length.
X
Because names must be so short, a system of abbreviations was developed to
organize the identifiers used within FunnelWeb. Each abbreviation consists
of a letter pair. Here are \i{some} of the abbreviations
used:\xx{identifier}{abbreviations}
X
X\begin{verbatim}
bp - Body Part.
cm - Compare. Used to prefix comparison routines that return [-1,0,1].
dc - Document component.
dm - Dump package.
el - Element.
eq - Equal. Used to prefix comparison routines that return a boolean.
ex - Expression.
f  - Global files.
ll - List of lists.
ln - Line record.
ls - List Package.
lr - Lister package.
ma - Macro.
mc - Macro Call.
mn - Macro Name.
op - Options package.
pr - Parser.
ps - Position record.
sc - Scrap record.
sn - Section.
tb - Table package.
ty - Typesetter directive.
wf - Write file package.
wl - Write with EOL (misc.c).
wr - Write          (misc.c).
X\end{verbatim}
X
X\thing{Pointers:} Variables or types denoting
pointers\xx{pointers}{naming} start with \dqp{p\_}.
X
X\thing{Types:} Names denoting types end in \dqp{\_t}.
Thus, a type for a pointer to a table would be named
X\p{p\_tb\_t}.\xx{types}{naming}
X
X\thing{File names:} All files\xx{filenames}{length}
used in FunnelWeb have file names that are
from one to eight characters long and file extensions that are from one to
three characters long. This ensures that the files can be portably moved
to all kinds of machines, even MSDOS!\x{MSDOS}
X
X\section{Use of Memory}
X\xx{use of}{memory}
X
XFunnelWeb is not a memory-stressed program. However, during its development,
problems with the management of memory seemed to crop up again and again.
This section documents some of these problems and the solutions adopted.
X
There are three places where memory can be obtained: the heap, the stack,
and from static variables. The following three sections deal with each
of these areas.
X
X\section{The Heap}
X\xx{heap}{memory}
X
One of the great frustrations of being a user is to find that a computer
program is complaining about lack of memory when one knows full well that
one has allocated at least ten times as much memory to the program as it
would ever need to do its job. The reason for such error messages usually
has to do with the programmer setting a fixed \dq{reasonable} limit to
a particular data structure and then locking it up into an array whose
bound is specified by a constant. While the use of arrays can increase the
speed of a program, it also means that the user cannot increase the capacity
of the program without obtaining the source code and recompiling it,
which is usually a daunting option.
X
The alternative is to use the heap for all data structures that can
grow in proportion to the size of the user's input. This rule has been
followed rigorously in FunnelWeb. This means that as memory spaces
increase, users will be able to hand their version of FunnelWeb more
memory without having to recompile it.
X
X\topicbreak
X
Some problems arose early on the Macintosh\x{Macintosh}
in the use of the heap. It seems
that some of the allocations I was attempting to make were failing for some
obscure reason, possibly my fault. Whatever it was, it went away when I
replaced direct calls to \p{malloc}\x{malloc}
with calls to a mini package I wrote
X(called \p{memory}) that allocated large chunks of memory and then doled out
small pieces as required by the rest of the
program.\xx{memory}{package}
X
Having a package to manage all the memory allocation had two other benefits.
X
XFirst, only one check was required in the entire program to see if memory
had run out (in the memory package), and if that failed, the program could
be brought to a screaming halt. This organization was far preferable to
having each piece of code that needed to allocate memory having to check
to see if \p{malloc} had failed.
X
Second, the decision to construct a mini-shell within FunnelWeb to
support regression testing meant that FunnelWeb proper could be run
many times in any given invocation of FunnelWeb. As a consequence it was
necessary to make sure that there was no memory
leakage\xx{memory}{leakage} between invocations
of FunnelWeb proper. This was accomplished by reworking the memory package
to operate a watermark system. The user of the package, when requesting
memory, could request \dq{temporary} or \dq{permanent}. If permanent, the
memory package forgot that it had allocated the memory. If temporary, the
memory package places the allocated block on a list. There was then a
function in the memory package that could be called to deallocate all the
temporary memory. Thus, so long as all requests for memory within FunnelWeb
proper were for temporary memory, and that memory was freed at the end of
every run, one could be sure that there was no memory leakage.
X
X\section{The Stack}
X\xx{stack}{memory}\xx{stack}{size}
X
XFor a while during the development of FunnelWeb a particularly nasty bug
proved extremely hard to find. The symptom was that FunnelWeb would crash,
sometimes at random, but more often upon entering a particular function.
In the end about a day of specific debugging was required before the problem
was tracked down to a stack problem. It turned out that somehow
X(either the fault of the Macintosh or the THINK~C language system), only
X6K was being allocated for stack space!!!!!!!
X
This experience led me immediately to go through the entire program and
eliminate (or remove to the heap) any automatic variable declarations that
used more than one hundred or so bytes.
X
The lesson is clearly that C~programs that use more than a few thousand bytes of
stack space are risking their portability. All large data structures should be
placed in the heap.
X
X\section{Static Variables}
X\xx{memory}{static}\xx{static}{variables}
X
Static variables also proved a problem on the Macintosh.
It turns out that
the Macintosh\x{Macintosh} THINK~C compiler\xx{ThinkC}{compiler}
does not allow more than 32K of statics
X\i{in the entire program}. For a while this restriction was
a serious threat to the program as it was discovered that constant strings
were included in this total! However, some searching revealed a compiler
option that removed the strings from the static category.
X
Nevertheless, the 32K limit is rather severe. Again, it seems that for
portability reasons, C~programs that use a lot of static variables are risking
their portability. As a result, the FunnelWeb code avoids static variables
where possible in favour of the heap.
X
X\section{Implementing Text Indentation}
X\xx{text}{indentation}
X
At one point during the development of FunnelWeb, text indentation was
fully implemented. However, it was subsequently removed because it was
considered a dangerous feature. This section records the way in which
text indentation was implemented so that if the feature ever has to be put
back, this technique can be used again.
X
X
X1. Create a new field in the \p{sc\_t} record call \p{sc\_postn}.
X
X\begin{verbatim}
X      char *sc_postn; /* Pointer in the range [sc_first,sc_last+1].           */
X                      /* It is the minimum possible value of sc_postn for     */
X                      /* which EOL does not appear in *sc_postn..*sc_last.    */
X                      /* i.e. Points to the byte following the first EOL in   */
X                      /* the scrap or sc_first if EOL does not appear.        */
X\end{verbatim}
X
X2. Modify the scanner so that it generates this field.
Sendtext should be modified so that
it accepts an argument for the \p{p\_postn} value.
X
X\begin{verbatim}
LOCAL void sendtext P_((p_ps_t,char *,char *,char *,bool));
LOCAL void sendtext(p_tkps,p_first,p_last,p_postn,is_white)
X/* Appends a text token to the end of the token list.                         */
X/* IN: p_ps is a pointer to a position structure giving the position of the   */
X/*     first character of the token.                                          */
X/* IN: p_first and p_last point to the first and last byte of the text scrap. */
X/* IN: p_postn has the same definition as sc_postn (see fwdata.h).            */
X/* IN: is_white should be set to TRUE iff scrap is entirely whitespace.       */
p_ps_t p_tkps;
char  *p_first;
char  *p_last;
char  *p_postn;
bool   is_white;
X{
X tk_t token;
X
X /* Empty text scraps should never be generated. */
X assert(p_first<=p_last,"sendtext: Text scrap bounds are bad.");
X
X /* If ch=EOL then we should be scanning more text, not shipping it! */
X assert(ch!=EOL,"senttext: Shipping text while still more to scan.");
X
X /* Check that p_postn is in range. See definition in fwdata.h. */
X assert(p_first<=p_postn && p_postn<=p_last+1,
X        "sendtext: p_postn is out of range.");
X
X /* Debug: Check the p_postn field using a brute force check. */
X {
X  char *i,*j;
X  j=p_first;
X  for (i=p_first;i<=p_last;i++)
X     if (*i==EOL)
X        j=i+1;
X  assert(j==p_postn,"sendtext: sc_postn field is incorrect.");
X }
X
X /* Load the text token. */
X token.tk_kind        = TK_TEXT;
X ASSIGN(token.tk_ps,*p_tkps);
X token.tk_sc.sc_first = p_first;
X token.tk_sc.sc_last  = p_last;
X token.tk_sc.sc_postn = p_postn;
X token.tk_white       = is_white;
X token.tk_parno       = 0;
X ls_add(token_list,PV &token);
X}
X\end{verbatim}
X
Then all the calls to sendtext have to be changed:
X
X\begin{verbatim}
X/* @ instructs FunnelWeb to replace the special construct with the */
X/* special character. Luckily one appears just before the @ !!     */
X/* Note: FALSE is OK because space is not a legal specialch.       */
X/* Note: Setting parameter p_postn to p_ch-1 is OK as EOL is not a */
X/*       legal specialch.                                          */
sendtext(&ps_spec,p_ch-1,p_ch-1,p_ch-1,FALSE);
break;
X
X/* + instructs FunnelWeb to insert an EOL. We can't look to the end of */
X/* the previous line to find an EOL as this might be the first line.   */
X/* Running ahead to the end of the line is expensive, and having the   */
X/* liner mini-package maintain a variable for it would be extra        */
X/* housekeeping. Instead of all this, we just point to a static.       */
X{CONST static char stateol = EOL;
X sendtext(&ps_spec,&stateol,&stateol,(&stateol)+1,TRUE);}
break;
X
X/* If we hit something that ends a text token */
X/* then we can transmit a white text token.   */
if (ch==specialch || ch==EOFCH)
X   {sendtext(&ps_start,p_first,p_ch-1,MAX(p_sol,p_first),TRUE); return;}
X
X/* Otherwise we have some more (non-white) text to scan. */
X/* We can then send a non-white text token.              */
while (ch!=specialch && ch!=EOFCH)
X   NEXTCH;
sendtext(&ps_start,p_first,p_ch-1,MAX(p_sol,p_first),FALSE);
X\end{verbatim}
X
The dump code needs to be changed too!
X
X\begin{verbatim}
X        wf_str(p_wf,"\"");
assert(token->tk_sc.sc_first !=NULL,"dm_tkls: NULL ptr1.");
assert(token->tk_sc.sc_last  !=NULL,"dm_tkls: NULL ptr2.");
for (i=token->tk_sc.sc_first; i<=token->tk_sc.sc_last; i++)
X  {
X   if (i==token->tk_sc.sc_postn)
X      wf_str(p_wf,"<postn>");
X   if (*i=='\n')
X      wf_wl(p_wf,"");
X   else
X      dm_byte(p_wf,*((ubyte_ *) i));
X  }
if (i==token->tk_sc.sc_postn)
X   wf_str(p_wf,"<postn>");
wf_str(p_wf,"\"");
X}
X\end{verbatim}
X
X3. Over in the Tangle module, create a massive array of pointers to scraps
to be used as a stack. Maintain pointers into the stack called \p{current} and
X\i{base} (similar to the blank indentation variables). Implement the following:
X
X\begin{itemize}
X
X\item To write out a scrap, scan it byte by byte. Output each byte. When
you hit an EOL, pop the stack back to \p{base}. Then write out an EOL
followed by the stack contents but writing each scrap only from \p{postn} to
end end of each scrap.
When you have finished the new scrap, push it on the stack.
X
X\item When you hit a new macro to expand, save \p{base}. Restore it later.
X
X\end{itemize}
X
The \p{postn} field solves the big problem of
how to cope with something like this:
X
X\begin{verbatim}
The rain in Spain
falls mainly @<on the plain@>
X\end{verbatim}
X
The trouble is that we want to text indent the lines in
X\p{@<on the plain@>} with
just \dqp{falls mainly~}. However, this string is only part of a scrap. The
solution is to get the scanner to record, in the \p{postn} field of each scrap,
the position of the first byte with a EOL-free run to the end of the scrap.
X
This scheme is very efficient because all we are doing is pushing and popping
pointers to scraps on a stack array. The main disadvantage is that the
array must necessarily be finite and would impose a limit on the depth
of indentation nesting (not a big problem).
X
X%==============================================================================%
X%                              Start of Ch2.tex                                %
X%==============================================================================%
END_OF_FILE
if test 18854 -ne `wc -c <'hackman/h_ch2.tex'`; then
    echo shar: \"'hackman/h_ch2.tex'\" unpacked with wrong size!
fi
# end of 'hackman/h_ch2.tex'
fi
if test -f 'hackman/h_ch4.tex' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'hackman/h_ch4.tex'\"
else
echo shar: Extracting \"'hackman/h_ch4.tex'\" \(18004 characters\)
sed "s/^X//" >'hackman/h_ch4.tex' <<'END_OF_FILE'
X%==============================================================================%
X%                              Start of Ch4.tex                                %
X%==============================================================================%
X%
X% Copyright
X% ---------
X% Copyright (C) 1992 Ross N. Williams.
X% This file contains a chapter of the FunnelWeb Hacker's Manual.
X% See the main TeX file for this manual for further information.
X%
X%==============================================================================%
X
X\chapter{FunnelWeb Future}
X\label{chapfuture}\xx{FunnelWeb}{future}
X
Previous chapters have explained the design of FunnelWeb and given reasons
for why it is the way it is. This chapter goes through each of the
aspects of FunnelWeb, and explores their problems, how they can be solved,
and lists opportunities for improvement.
X
X\section{Documentation}
X\x{documentation}
X
X\thing{An official example:} A official example program written using
XFunnelWeb should be constructed and made available.\xx{official}{example}
X
X\thing{Index program:} In order to typeset the documentation, a portable
index sorting program is required. One should be written and added to the
distribution kit.\xx{index}{program} Perhaps this could be the official
example!
X
X\section{Command Line Interface}
X\xx{command}{interface}
X
X\thing{Buffer length:} Currently the FunnelWeb shell uses the
X\p{COMLINE\_MAX} constant to size its internal command line buffers.
This is untenable. The maximum length of a shell command line should
not be machine dependent.
X
X\thing{Antiquated Features:} As the FunnelWeb language develops, it is likely
that some changes will have to be made that will render one or more
language constructs obsolete. When this happens, it may be necessary to
add a command line option that has the power to turn on and off warnings or
errors flagging antiquated features.\xx{antiquated}{features}
X
X\section{Shell Interpreter}
X\xx{shell}{interpreter}\xx{command}{interpreter}
X
X\thing{SETALL command:} When writing FunnelWeb scripts, it is sometimes
desirable to set \i{all} of FunnelWeb's options\x{options}
to some particular value
so that the script is not vulnerable to changes in FunnelWeb's default
values which might occur from time to time. To this end, it may be worth
creating a \dqp{SETALL} command that is identical to the \dqp{SET} command
except that it will generate an error if the value of an option is not
specified explicitly.\xx{setall}{command}
X
X\thing{Recursion test:} A test should be added to test for recursive
invocation in a shellscript.\xx{recursion}{test}
X
X\thing{Diagnostic counting:} The code for counting diagnostics in the
script interpreter is rather messy and perhaps even buggy. It should be
cleaned up and commented.\xx{diagnostic}{counting}
X
X\thing{Argument counting:} In the \p{command.c} module, there is a variable
that counts the arguments to a command. Currently it takes the value of
the number of parameters including the command verb. This has turned out
to make the code less readable. It should be changed to be the number of
arguments to the command verb.
X
X\thing{Make facility:} It may be worth building some sort of make facility
into the script language so as to support machines such as the Macintosh
that do not already have this facility.\x{make}
X
X\thing{Signature file:} One problem with using FunnelWeb in conjunction with
an external \p{Make} facility is that a user might change a FunnelWeb source
file without making changes that will affect the files that it generates.
If FunnelWeb is then run and the \dqp{+D} option is on, then the output
files will be deleted (to avoid further \p{Make} propagations).
If \p{Make} then has a production linking the \p{.fw} file to its output
files, then it may conclude that the output files are still out of date.
To solve the problem, FunnelWeb could be changed to write a \p{.sig} file
whenever it processes a \p{.fw} file. The \p{Make} production could then
be wired up to link
the \p{.fw} file to the \p{.sig} file instead of to the output
files.\xx{signature}{file}
X
X\section{Language Design}
X\xx{language}{design}
X
Some proposed changes to FunnelWeb do not correspond to
any particular component of FunnelWeb
and are really to do with the design of the input language.
X
X\thing{Output or file?:} The \dqp{@O} special sequence for defining an output
file is somewhat non-mnemonic and can be confused with zero (\dqp{0}). Perhaps
it should be replaced by the \dqp{@F} sequence.
X
X\thing{Syntax of section names:} Currently section names use
the same syntax as macro names. For example \dqp{@<Sloth@>}. It can be
argued that angle brackets should be reserved only for macro names and that
some other syntax should be found for delimiting section names. This is not
a clear issue. It could also be argued that they are both names, and that
because sections can inherit their names from the macros they contain, that
the names are of the same \dq{type}.\xx{section}{syntax}
X
X\thing{One macro per section:} One particular style of using FunnelWeb is
to have at most one macro definition per section. It may be worth adding
a pragma that instructs FunnelWeb to enforce this.
X
X\thing{Should @\{ suppress EOL?:} When defining a macro in FunnelWeb, it
seems to be rule rather than the exception that the
X\dqp{@\{} be followed by \dqp{@-}. This suppresses the EOL on the definition
line, allowing the first line of the macro to be placed immediately
above and in line with the other
lines without introducing an EOL at the start of the macro text.
One option is to introduce a pragma to determine whether to suppress EOLs
following \dqp{@\{}.
X
X\thing{Pragma syntax:} It is not clear how \dq{loose} the syntax of pragmas
should be. Perhaps they should be case insensitive.\xx{pragma}{syntax}
X
X\thing{Conditionals:} Depending on demand, it may be worth reintroducing
some sort of conditional feature into FunnelWeb. However, it would have to
be very simple to compete with the various ways in which conditionals
can already be fudged within FunnelWeb as it stands.\x{conditionals}
X
X\thing{File markers:} It might be worth modifying the language so that
a special syntactical marker is required at the start and end of files.
This will assist in detecting truncations and other
corruptions.\xx{file}{markers}
X
X\thing{Formal parameter lists:} It might be worth changing over to a
syntax for formal parameter lists that does not require the \p{@(} and
X\p{@)}. However, they could be retained as optional for backward
compatibility.\xx{parameter list}{formal}
X
X\section{Scanner/Mapper}
X\x{scanner}\x{mapper}
X
X\thing{All non-contiguous mappings:} Currently FunnelWeb requires that all
input files be mapped into a contiguous lump of memory. This caused problems
for two reasons. First, to do this, one has to allocate the memory first,
and to do that, you have to know how long the file is, and it turns out that
finding out the length of a file in a portable manner is very inefficient.
Second, although IBM PC compatibles may have megabytes of memory, it is
segmented into blocks of at most 64K. This means that FunnelWeb currently
cannot read a file longer than 64K on a PC.\xx{contiguous}{memory}
X
These problems could be avoided if the mapper and scanner were reorganized to
allow input files to be read in and stored as a linked list of chunks of text
rather than a contiguous block.
X
X\thing{EOL is unspecifiable:} FunnelWeb uses ASCII character decimal ten (10)
internally to represent logical end-of-line and is currently organized so that
if one of these is inserted into the text by the user using a
X\dqp{@\circumflex{}D(10)}, it will be written out as a logical end of line,
rather than as a single ASCII character 10. This should be
fixed.\xx{representation}{EOL}
X
X\thing{Allow mnemonics for unprintables:} FunnelWeb allows users to insert
unprintable characters into the output using the \dqp{@\circumflex{}D(ddd)}
special sequence. Perhaps it would be changed so that it understands ASCII
standard mnemonics such as \dqp{LF} as well as ASCII
numbers.\xx{ASCII}{mnemonics}
X
X\thing{Version pragma:} A \dqp{version} pragma should be added that allows
the user to specify in the input file the version of FunnelWeb that was
around when the input file was created. At a later date, such a construct
would be very useful for determining how an input file should be updated
if the FunnelWeb language has changed between
versions.\xx{version}{pragma}
X
X\section{Parser}
X\x{parser}
X
There are no proposals to change the parser except as a consequence of
other proposals.
X
X\section{Analyser}
X\x{analyser}
X
X\thing{Recursion detection:} Currently the FunnelWeb analyser flags, with
an error, all macros with an infinite expansion. This would be best
changed to flagging all macros that are directly or indirectly recursive.
To do this, Tarjan's algorithm\paper{Tarjan72}\xn{Robert Endre}{Tarjan}
for the detection of strong components should
be installed.\xx{recursion}{detection}
X
X\thing{Once only macros:} By default FunnelWeb prevents a macro from being
called more than once unless it has a \dqp{@M} associated with it. However,
XFunnelWeb does allow a macro that calls such a macro to be called more
than once. Perhaps this \dq{loophole} should be plugged somehow.
X
X
X\section{Tangle}
X\x{tangle}
X
The Tangler is one of the cleanest components of FunnelWeb, as basically all it
has to do is expand some very well-defined macros.
X
X\thing{Text indentation:} Currently FunnelWeb supports \i{no indentation}
and \i{blank indentation}. A third form could be added if it was considered
necessary. \i{Text indentation} is the same as \i{blank indentation} except
that instead of indenting with blanks, FunnelWeb would indent with the
text to the left of the called macro. This facility could be useful for
commenting out large bodies of text in languages that do not have
multi-line comments (e.g. Ada). A discussion of the pros and cons of this
form of indentation appears earlier.\xx{text}{indentation}
X
X\section{Weave}
X\x{weave}
X
Perhaps FunnelWeb's weakest aspect is its typesetting facility.
X
X
X\thing{Align table of contents:} When FunnelWeb generates a table of contents,
the section numbers are not quite aligned with the start of the controlling
heading above them.\x{table of contents}
X
X\thing{Typesetting strength:} It should be possible to specify the
level of typesetting strength for headings so that short documents do not
look overdone when typeset. A new pragma would be good for
this.\xx{strength}{typesetting}
X
X\thing{Typeset a portion:} Sometimes it is desirable to typeset just a
portion of a program. A command line option could be added to do
this. The option could accept as its argument, a string containing a list
of section numbers or heading names.
X
X\thing{Generic typesetter option:} In addition to building in a number
of different versions of Weave, one for each popular typesetter, it would be
possible to add a special generic format where the typeset output is
expressed in terms of \i{FunnelWeb macros}. The user could then specify
macro definitions for a non-supported typesetter and run the output
through FunnelWeb Tangle to get a typeset file in a format suitable for the
unsupported typesetter.\xx{typesetter}{generic}
X
X\thing{Suppression of include files:} It should be possible to specify
in the input file that particular included files not appear in the
typeset output. Currently, the fact that an inclusion has occurred is
not even represented in the typeset output. Suppression of inclusions
is particularly necessary where a library of macros has been included
at the top of each of a group of source files.\xx{include file}{suppression}
X
X\thing{Cross reference of identifiers:} WEB provides a list of identifiers
and a list of all the definitions in which they are used. A similar
feature could be added to FunnelWeb.\xx{cross}{references}
X
X\thing{Support for non-printables:} Currently FunnelWeb does not provide
support for typesetting the special \dqp{@\circumflex(num)} sequences.
This should be added.
X
X\thing{Support for @+ sequences:} Currently Weave does not see \dqp{@+}
sequences as such. Instead it perceives them as ordinary EOLs. However,
there are arguments for typesetting them specially.
X
X\thing{Typeset text in macro bodies:} One of the much-loved features
of WEB is the way that it allows the user to switch recursively between
document and program formats. FunnelWeb does not allow this, but
should. In FunnelWeb, the delimiters \dqp{@\{} and \dqp{@\}} are already
used consistently to delimit macro text. The \dqp{@[} and \dqp{@]} sequences
have been reserved for the delimitation of documentation text.
X
X\thing{Non-tt typesetting:} The current version of FunnelWeb sets all its
macro text in \p{tt font}. This is both a blessing and a curse. It is a
blessing because it connects the reader directly to the code, with no
complicated intermediary. It is a curse because it looks ugly compared to
the beautifully typeset programs produced by other literate programming
tools.
X
The difficulty with adding such beautiful typesetting is that it is
necessarily language-specific. Keywords and syntax differ from language
to language and it would not be easy to come up with a set of language
independent rules.
X
One approach is to write a set of Weave back-ends, one for each language.
Another approach is to \i{generate} back ends. This is the approach
taken in the \i{Spider} system\paper{Ramsey89}.\x{spider}
In the \i{Spider} system,
the programmer writes production rules for converting lexical components
of the program text into typesetter instructions. The \i{Spider} program
reads these rules and generates a new version of WEB suited for the target
language.
X
XFor FunnelWeb a slightly different system is proposed in which Spider-like
rules appear in the input file and are used directly by Weave to perform the
typesetting. An intermediate abstract typesetting language could be used
so that the productions can be made language specific, but not typesetter
specific.
X
X\section{Lister}
X\x{lister}
X
X\thing{Glue factor:} A glue factor could be added that determines how many
lines can be in between two diagnostics in the listing before the two
groups of lines are joined together in the listing with no intervening
ellipsis.\xx{glue}{factor}
X
X\section{Diagnostics}
X\x{diagnostics}
X
X\thing{Advisory information:} Some of FunnelWeb's diagnostics provide
a detailed explanatory paragraph. While this information might be useful the
first time, it has the capacity to clog up a listing file if the user has
made the same error many times. To solve this problem, FunnelWeb could be
modified so that such explanations are only displayed the first time the
error occurs.
X
X\thing{Abort after n errors:} A facility could be added to prevent
XFunnelWeb's scanning, parsing, and analysing phases from continuing if
a certain number of errors have already been issued.
X
X
X\section{Speed}
X\x{speed}\x{efficiency}
X
X\thing{Measurement of speed:} Although FunnelWeb can generate a breakdown
of where it is spending its time, it does not give a final rating in
lines per minute. This should be added.
X
X\thing{Find the hot spots:} Although FunnelWeb has been designed to allow
high speed, not much effort has so far been made to make it fast. This should
be done.
X
X\thing{Change some declarations:} FunnelWeb is full of variable declarations
where the variables are wider than they need be. Replacing these might speed
it up.
X
X\section{Correctness}
X\x{correctness}
X
X\thing{Bounds analysis:} Not much effort has gone into the design of
XFunnelWeb's input boundaries. An analysis should be made of FunnelWeb's
behaviour when the following quantities are stretched:
X
X\begin{itemize}
X\item Input line length.
X\item Input file size.
X\item Number of macros.
X\item Length of macro.
X\end{itemize}
X
In particular, FunnelWeb's behaviour at 32K and 64K boundaries should be
observed.
X
X\thing{Stack detection:} Macintosh THINK-C provides just 6K of memory for
the stack. It might be worth adding checks to make sure that the stack is
not being blown.
X
X\section{Test Suite}
X\xx{test}{suite}
X
The following tests should be added to the test suite:
X
X\begin{verbatim}
Lister
X------
X   LR01: Test with a full listing with no diagnostics.
X   LR02: Test with a full listing with diagnostics.
X   LR03: Test with an abbreviated listing with no diagnostics.
X   LR04: Test with an abbreviated listing with diagnostics.
X   LR05: Test error context system with nearby diagnostics.
X
Boundary Cases
X--------------
Static analysis might preclude the need for most of these tests.
X   BC01: Test what happens when memory runs out.
X   BC02: Test on a file with a single line of a megabyte.
X   BC03: Test on a file of a megabyte of EOLs.
X   BC04: Generate an output file with an extremely long line.
X   BC05: Generate an output file with one million lines.
X   BC06: Test on a file with very many macros.
X
General
X-------
X   GN01: A large legal input file exercising as many features as possible.
X         1. Test listing file.
X         2. Test output files.
X         3. Test typeset file.
X   GN... A selection of ten real-life FunnelWeb files.
X\end{verbatim}
X
X\section{Machine-Specific Changes}
X
X\thing{Icon for the Macintosh:} Currently no icon is supplied for the
Macintosh version of FunnelWeb. An icon depicting a spider or a funnelled
web of some kind would seem appropriate.
X
X\section{Summary}
X
This chapter has describes some of the problems with FunnelWeb and some of the
opportunities that exist for improving it. The direction and speed in which
XFunnelWeb will develop will depend largely on user feedback. If you have any
strong feelings on where FunnelWeb should go, please email them to
Ross Williams (\p{[e-mail]}).
X
X
X%==============================================================================%
X%                              Start of Ch4.tex                                %
X%==============================================================================%
END_OF_FILE
if test 18004 -ne `wc -c <'hackman/h_ch4.tex'`; then
    echo shar: \"'hackman/h_ch4.tex'\" unpacked with wrong size!
fi
# end of 'hackman/h_ch4.tex'
fi
if test -f 'sources/help_gnu.txt' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'sources/help_gnu.txt'\"
else
echo shar: Extracting \"'sources/help_gnu.txt'\" \(17977 characters\)
sed "s/^X//" >'sources/help_gnu.txt' <<'END_OF_FILE'
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X
XEach version is given a distinguishing version number.  If the Program
specifies a version number of this License which applies to it and "any
later version", you have the option of following the terms and conditions
either of that version or of any later version published by the Free
Software Foundation.  If the Program does not specify a version number of
this License, you may choose any version ever published by the Free Software
XFoundation.
X
X  10. If you wish to incorporate parts of the Program into other free
programs whose distribution conditions are different, write to the author
to ask for permission.  For software which is copyrighted by the Free
Software Foundation, write to the Free Software Foundation; we sometimes
make exceptions for this.  Our decision will be guided by the two goals
of preserving the free status of all derivatives of our free software and
of promoting the sharing and reuse of software generally.
X
X                NO WARRANTY
X
X  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
XFOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
REPAIR OR CORRECTION.
X
X  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.
X
X             END OF TERMS AND CONDITIONS
X
X    Appendix: How to Apply These Terms to Your New Programs
X
X  If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.
X
X  To do so, attach the following notices to the program.  It is safest
to attach them to the start of each source file to most effectively
convey the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.
X
X    <one line to give the program's name and a brief idea of what it does.>
X    Copyright (C) 19yy  <name of author>
X
X    This program is free software; you can redistribute it and/or modify
X    it under the terms of the GNU General Public License as published by
X    the Free Software Foundation; either version 2 of the License, or
X    (at your option) any later version.
X
X    This program is distributed in the hope that it will be useful,
X    but WITHOUT ANY WARRANTY; without even the implied warranty of
X    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
X    GNU General Public License for more details.
X
X    You should have received a copy of the GNU General Public License
X    along with this program; if not, write to the Free Software
X    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
X
Also add information on how to contact you by electronic and paper mail.
X
If the program is interactive, make it output a short notice like this
when it starts in an interactive mode:
X
X    Gnomovision version 69, Copyright (C) 19yy name of author
X    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
X    This is free software, and you are welcome to redistribute it
X    under certain conditions; type `show c' for details.
X
The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License.  Of course, the commands you use may
be called something other than `show w' and `show c'; they could even be
mouse-clicks or menu items--whatever suits your program.
X
You should also get your employer (if you work as a programmer) or your
school, if any, to sign a "copyright disclaimer" for the program, if
necessary.  Here is a sample; alter the names:
X
X  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
X  `Gnomovision' (which makes passes at compilers) written by James Hacker.
X
X  <signature of Ty Coon>, 1 April 1989
X  Ty Coon, President of Vice
X
This General Public License does not permit incorporating your program into
proprietary programs.  If your program is a subroutine library, you may
consider it more useful to permit linking proprietary applications with the
library.  If this is what you want to do, use the GNU Library General
Public License instead of this License.
END_OF_FILE
if test 17977 -ne `wc -c <'sources/help_gnu.txt'`; then
    echo shar: \"'sources/help_gnu.txt'\" unpacked with wrong size!
fi
# end of 'sources/help_gnu.txt'
fi
if test -f 'sources/tangle.c' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'sources/tangle.c'\"
else
echo shar: Extracting \"'sources/tangle.c'\" \(18625 characters\)
sed "s/^X//" >'sources/tangle.c' <<'END_OF_FILE'
X/*##############################################################################
X
XFUNNNELWEB COPYRIGHT
X====================
XFunnelWeb is a literate-programming macro preprocessor.
X
Copyright (C) 1992 Ross N. Williams.
X
X   Ross N. Williams
X   [e-mail]
X   16 Lerwick Avenue, Hazelwood Park 5066, Australia.
X
This program is free software; you can redistribute it and/or modify
it under the terms of Version 2 of the GNU General Public License as
published by the Free Software Foundation.
X
This program is distributed WITHOUT ANY WARRANTY; without even the implied
warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See Version 2 of the GNU General Public License for more details.
X
You should have received a copy of Version 2 of the GNU General Public
License along with this program. If not, you can FTP the license from
prep.ai.mit.edu/pub/gnu/COPYING-2 or write to the Free Software
XFoundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
X
Section 2a of the license requires that all changes to this file be
recorded prominently in this file. Please record all changes here.
X
Programmers:
X   RNW  Ross N. Williams  [e-mail]
X
Changes:
X   07-May-1992  RNW  Program prepared for release under GNU GPL V2.
X
X##############################################################################*/
X
X
X/******************************************************************************/
X/*                                   TANGLE.C                                 */
X/******************************************************************************/
X
X/* Note: In this module, "ex_" at the start of a function name means "expand" */
X/*       rather than the standard meaning of "ex" of "expression.             */
X
X/******************************************************************************/
X
X#include "style.h"
X
X#include "as.h"
X#include "data.h"
X#include "lister.h"
X#include "memory.h"
X#include "misc.h"
X#include "table.h"
X#include "tangle.h"
X#include "writfile.h"
X
X/******************************************************************************/
X
X/* The following variable keeps track of the output line number. This is      */
X/* needed to report lines that are too long.                                  */
LOCVAR ulong lineno;
X
X/* Last line for which error message was generated.    */
LOCVAR ulong errlin;
X
X/* Number of too-long lines seen so far in this file. */
LOCVAR ulong numlong;
X/* Number of long line error messages we can tolerate per product file. */
X#define LONGMESS 5
X
X/* Note: An indentation of n means n blanks before current material.          */
X/* tgindent is a global variable set by the scanner. It is TRUE if blank      */
X/* indenting is required and FALSE if no indenting is required.               */
LOCVAR ulong ind_base;  /* Base indenting level of macro being expanded.      */
LOCVAR ulong ind_curr;  /* Current indenting position.                        */
X
LOCVAR char  *fn_targ;  /* Name of current (target) product file.             */
LOCVAR wf_t  f_o;       /* Current product file.                              */
X
X/******************************************************************************/
X
X/* The expression expansion function has to have a forward declaration. */
LOCAL void ex_ex P_((p_ells_t));
X
X/******************************************************************************/
X
LOCAL void eolblank P_((ulong));
LOCAL void eolblank(n)
X/* Writes an EOL followed by n blanks to the product file. Efficiently!       */
ulong n;
X{
X /* The whole aim of this routine is to write blanks EFFICIENTLY. In          */
X /* particular avoiding any per-char procedure call overhead (e.g. calls to   */
X /* wf_chr). The best way to avoid this is to create a static array of blanks */
X /* and write out large blocks of blanks all at once.                         */
X#define BLANKLEN 100             /* Number of BLANKS in blank array.          */
X STAVAR bool notinit=TRUE;       /* Has blank array been initialized?         */
X STAVAR char blanks[1+BLANKLEN]; /* EOL followed by BLANKLEN blanks.          */
X
X /* Set up the blank array. This only ever done once because of the static    */
X /* boolean. Note that use of an initialized static here does not make the    */
X /* code non-reentrant, as the state does not change after initialization.    */
X if (notinit)
X    {blanks[0]=EOL; memset(blanks+1,' ',(size_t) BLANKLEN); notinit=FALSE;}
X
X /* The most common case will be a small indentation. Do this case fast. */
X if (n<=BLANKLEN)
X    wf_blk(&f_o,&blanks[0],(size_t) n+1);
X else
X   {
X    /* We now know that n>=BLANKLEN. Write out a long line with \n at front. */
X    wf_blk(&f_o,&blanks[0],BLANKLEN+1); n-=BLANKLEN;
X
X    /* Now get into large scale blank production! */
X    while (n>0)
X      {
X       ulong len=MIN(n,BLANKLEN);
X       wf_blk(&f_o,&blanks[1],(size_t) len); n-=len;
X      }
X   }
X}
X
X/******************************************************************************/
X
X#define SENDLINE {wl_l(linet1); if (option.op_s_b) wl_sj(linet1);}
X
LOCAL void ex_sc P_((p_sc_t));
LOCAL void ex_sc(p_sc)
X/* This function writes the specified scrap to the product file. It also      */
X/* performs two other tasks:                                                  */
X/*    If tgindent==TRUE, inserts indentation at the start of each line.       */
X/*    If tglinmax>0, checks for product file lines longer than tglinmax.      */
X/* Note: The speed of this routine is fairly critical.                        */
p_sc_t p_sc;
X{
X /* Output of a scrap is straightforward if we are not inserting indentation  */
X /* or watching for lines that are too long. If neither of these tasks have   */
X /* to be performed, we can bang the scrap out directly with a wf_blk.        */
X if (!tgindent && tglinmax==TGMAXINF)
X   {
X    wf_blk(&f_o, p_sc->sc_first, (size_t) (p_sc->sc_last-p_sc->sc_first+1));
X    return;
X   }
X
X /* Otherwise it gets rather messy. Basically, we have to watch for end of    */
X /* lines and perform special actions there.                                  */
X /* ind_curr is the number of characters already written to the current line. */
X {
X  char *p      = p_sc->sc_first;
X  char *p_post = p_sc->sc_last+1;
X  while (TRUE)
X    {
X     char *p_sot = p;  /* SOT=Start of Text. */
X
X     /* Scan scrap until we hit either its end or an EOL. */
X     while (p!=p_post && *p!=EOL) p++;
X
X     /* Assert: p==p_post || (p_sot<=p<p_post && *p==EOL). */
X
X     /* If we scanned any non-EOL text, write out what we scanned. */
X     if (p>p_sot) {wf_blk(&f_o,p_sot,(size_t) (p-p_sot));ind_curr+=p-p_sot;}
X
X     /* Check that what we have written so far is not too long.            */
X     /* Performing this check here rather than with the EOL processing     */
X     /* means that we will detect overlong final non-EOL terminated lines. */
X     /* Use of errlin suppresses multiple errors on the same line.         */
X     /* Note: We assume that TGMAXINF is very large.                       */
X     if (ind_curr>tglinmax && lineno!=errlin)
X       {
X        numlong++;
X        if (numlong <= LONGMESS)
X          {
X           if (option.op_b7_b)
X              sprintf(linet1,
X                      "E: Product file line is too long (line %lu of \"%s\").",
X                             (ulong) lineno,SUPPNAME);
X           else
X              sprintf(linet1,
X                      "E: Product file line is too long (line %lu of \"%s\").",
X                             (ulong) lineno,fn_targ);
X           SENDLINE;
X           if (numlong==1)
X             {
X              sprintf(linet1,"   Product file line length limit is %lu characters.",
X                             (ulong) tglinmax);
X              SENDLINE;
X              sprintf(linet1,"   Note: You can change the limit by specifying.");
X              SENDLINE;
X              sprintf(linet1,"      @p maximum_output_line_length = <desired length>");
X              SENDLINE;
X              sprintf(linet1,"   somewhere in the input file.");
X              SENDLINE;
X             }
X           errlin=lineno;
X           num_err++;
X          }
X        if (numlong == LONGMESS+1)
X          {
X           sprintf(linet1,
X           "Further line-too-long warnings for file \"%s\" have been suppressed.",
X              fn_targ);
X           SENDLINE;
X          }
X       }
X
X     /* Exit if we hit the end of the scrap. */
X     if (p==p_post) break;
X
X     /* Move past the EOL and bump up the line counter. */
X     p++; lineno++;
X
X     /* Output an EOL with indentation if desired. */
X     if (tgindent)
X        eolblank(ind_base);
X     else
X        wf_chr(&f_o,EOL);
X     ind_curr=ind_base;
X    }
X }
X}
X
X/******************************************************************************/
X
LOCAL void ex_eltx P_((p_el_t));
LOCAL void ex_eltx(p_el)
X/* Writes the given text element to the product file. */
p_el_t p_el;
X{
X p_sc_t p_sc;
X
X /* Make sure that we have actually been handed a text element. */
X as_cold(p_el->el_kind==EL_TEXT,"ex_eltx: Not a text element!");
X
X /* Write all the scraps in the text list to the product file. */
X ls_fir(p_el->el_text);
X while (TRUE)
X   {
X    ls_nxt(p_el->el_text,PPV &p_sc);
X    if (p_sc==NULL) break;
X    ex_sc(p_sc);
X   }
X}
X
X/******************************************************************************/
X
LOCAL void ex_elpr P_((p_el_t));
LOCAL void ex_elpr(p_el)
X/* Write the expansion of the given parameter element to the product file. */
p_el_t p_el;
X{
X p_ell3_t  actn = p_el->el_which->ma_actn;
X p_elll_t *pp_parls;
X p_ells_t *pp_exp;
X ulong    ind_save;
X
X /* Make sure that we have been handed a parameter element. */
X as_cold(p_el->el_kind==EL_PARM,"ex_elpr: Not a parameter element!");
X
X /* Save the current indentation base and set it to the current level. */
X ind_save=ind_base;
X ind_base=ind_curr;
X
X /* Get a pointer to the most recent parameter list of the target macro. */
X ls_loo(actn,ls_len(actn),PPV &pp_parls);
X
X /* Get the expression corresponding to the el_parno'th parameter. */
X ls_loo(*pp_parls,p_el->el_parno,PPV &pp_exp);
X
X /* Expand that expression. */
X ex_ex(*pp_exp);
X
X /* Restore the indentation base. */
X ind_base=ind_save;
X}
X
X/******************************************************************************/
X
LOCAL void ex_elin P_((p_el_t));
LOCAL void ex_elin(p_el)
X/* Expand invocation element. */
p_el_t p_el;
X{
X p_ma_t p_ma;
X p_bp_t p_bp;
X ulong  ind_save;
X p_void p_mark;
X
X /* Make sure that we have been handed an invocation element. */
X as_cold(p_el->el_kind==EL_INVC,"ex_elin: Not an invocation element!");
X
X /* Save the current indentation base and set it to the current level. */
X ind_save=ind_base;
X ind_base=ind_curr;
X
X /* Grab a pointer to the macro being invoked. */
X p_ma=p_el->el_p_mac;
X
X /* Push the actual parameter list onto the invoked macro's activation list. */
X ls_add(p_ma->ma_actn,PV &p_el->el_parls);
X
X /* Expand each body part expression. */
X ls_fir(p_ma->ma_defn.md_body);
X while (TRUE)
X   {
X    ls_nxt(p_ma->ma_defn.md_body,PPV &p_bp);
X    if (p_bp==NULL) break;
X    p_mark=ls_mar(p_ma->ma_defn.md_body); /* Protect againt recursion. */
X    ex_ex(p_bp->bp_ex);
X    ls_set(p_ma->ma_defn.md_body,p_mark);
X   }
X
X /* Pop the activated macro's parameter list. */
X ls_lop(p_ma->ma_actn);
X
X /* Restore the indentation base. */
X ind_base=ind_save;
X}
X
X/******************************************************************************/
X
LOCAL void ex_ex(p_exp)
X/* Expand the specified expression. */
p_ells_t p_exp;
X{
X p_void p_mark;
X
X /* We need to save the current position in the expression list in case we    */
X /* are being recursively invoked (e.g. in @<X@>@(@"@<X@>@(@"sloth@"@)@"@).   */
X ls_fir(p_exp);
X while (TRUE)
X   {
X    p_el_t p_el;
X    ls_nxt(p_exp,PPV &p_el);
X    if (p_el==NULL) break;
X    p_mark=ls_mar(p_exp);
X    switch (p_el->el_kind)
X      {
X       case EL_TEXT: ex_eltx(p_el); break;
X       case EL_INVC: ex_elin(p_el); break;
X       case EL_PARM: ex_elpr(p_el); break;
X       default     : as_bomb("ex_ex: Case defaulted.");
X      }
X    ls_set(p_exp,p_mark);
X   }
X}
X
X/******************************************************************************/
X
LOCAL void ex_file P_((p_ma_t));
LOCAL void ex_file(p_ma)
X/* This function accepts a pointer to a macro. It creates a product file      */
X/* with the same name as the macro (inheriting any filename parts given in    */
X/* the command line) and expands the macro, writing the expansion to the      */
X/* product file.                                                              */
p_ma_t  p_ma;
X{
X fn_t  fn_tmp;  /* Name of temporary file.                                    */
X bool  renfil;   /* Do we wish to rename product file?                        */
X bool  istarg;   /* Does a target file already exist?                         */
X
X /* Writing product files differs to the other output files. With non         */
X /* critical files such as the listing file that are really just logs,        */
X /* generation of half a listing file is acceptable if not desirable. However */
X /* in the case of product files, it is very bad to generate half a product   */
X /* file; far better to generate none at all. For this reason, and also       */
X /* because of the presence of the D option (which prohibits the writing      */
X /* of product files identical to existing files (to prevent MAKE             */
X /* propagations)) it is best to write a temporary file and then rename it.   */
X
X /* Construct the target file name.                                           */
X strcpy(fn_targ,"");                /* Start with an empty name.              */
X fn_ins(fn_targ,&option.op_o_s[0]);
X fn_ins(fn_targ,&p_ma->ma_name[0]);
X
X /* The temporary file has to inherit too, because the output directory may   */
X /* not be the default directory and some computers can't rename across       */
X /* directories (and we have to rename it later).                             */
X strcpy(fn_tmp,fn_targ);
X fn_ins(fn_tmp,fn_temp());
X
X /* Expand the macro to the temporary file. */
X wf_ini(&f_o,TRUE);
X wf_ope(&f_o,fn_tmp);
X if (wf_err(&f_o))
X   {
X    sprintf(linet1,"Error creating temporary product file \"%s\".",&fn_tmp[0]);
X    wl_sjl(linet1);
X    (void) remove(fn_tmp);
X    goto severe;
X   }
X
X /* Now expand the target macro into the file. */
X {
X  el_t el;
X  el.el_kind  = EL_INVC;
X  el.el_p_mac = p_ma;
X  el.el_parls = ls_cre(sizeof(p_ells_t));
X  /* Note: We don't set el_pretx and el_postx as they are not used here. */
X  ind_base = 0;
X  ind_curr = 0;
X  lineno   = 1;
X  errlin   = 0;
X  numlong  = 0;
X  ex_elin(&el);
X }
X
X /* Make sure that there weren't any errors writing to the product file. */
X if (wf_err(&f_o))
X   {
X    sprintf(linet1,"S: Error writing to temporary product file \"%s\".",&fn_tmp[0]);
X    wl_sjl(linet1);
X    (void) remove(fn_tmp);
X    goto severe;
X   }
X
X /* Close the product file. */
X wf_clo(&f_o);
X if (wf_err(&f_o))
X   {
X    sprintf(linet1,"S: Error closing temporary product file \"%s\".",&fn_tmp[0]);
X    wl_sjl(linet1);
X    (void) remove(fn_tmp);
X    goto severe;
X   }
X
X /* The rest of the code in this function copes with the renaming. */
X
X /* By default, we wish to rename the temporary file. */
X renfil=TRUE;
X
X /* Deal with any existing file of the target name. */
X istarg=fexists(fn_targ);
X if (istarg && option.op_d_b)
X   {
X    /* A target already exists, and the D option is on. If the target is      */
X    /* identical to the temporary, we can simply delete the temporary!        */
X    char *errstr;
X    bool  same;
X    errstr=eq_files(fn_tmp,fn_targ,&same);
X    if (errstr != NULL)
X      {
X       wl_sjl("S: Error comparing temporary file with previous product file.");
X       wl_sjl("(A comparison was attempted because the D option was turned on.)");
X       wl_sjl("Error from comparison routine was as follows (first=temp):");
X       wr_sjl("   ");wl_sjl(errstr);
X       sprintf(linet1,"Temporary file name was \"%s\".",&fn_tmp[0]);
X       wl_sjl(linet1);
X       sprintf(linet1,"Product   file name was \"%s\".",fn_targ);
X       wl_sjl(linet1);
X       wl_sjl("FunnelWeb will leave both files intact so you can look at them.");
X       goto severe;
X      }
X    /* If the two files are the same, we can simply delete the temporary. */
X    if (same)
X      {
X       int status;
X       status=remove(fn_tmp);
X       if (status != REMOVE_S)
X {
X  sprintf(linet1,"S: Error deleting (under +D option) temporary file \"%s\".",&fn_tmp[0]);
X  wl_sjl(linet1);
X  goto severe;
X }
X       sprintf(linet1,"Deleted identical product file \"%s\".",fn_targ);
X       wl_sjl(linet1);
X       renfil=FALSE;
X      }
X   }
X
X if (renfil)
X   {
X    int status;
X    /* We need to delete any existing file of the target name. */
X    if (istarg)
X      {
X       status=remove(fn_targ);
X       if (status != REMOVE_S)
X {
X  sprintf(linet1,"S: Error deleting existing product file \"%s\".",fn_targ);
X  wl_sjl(linet1);
X  goto severe;
X }
X      }
X    /* Rename the temporary file to the product file. */
X    status=rename(fn_tmp,fn_targ);
X    if (status != RENAME_S)
X      {
X       wl_sjl("S: Error renaming temporary product file to product file.");
X       sprintf(linet1,"Temporary file name was \"%s\".",&fn_tmp[0]);
X       wl_sjl(linet1);
X       sprintf(linet1,"Product   file name was \"%s\".",fn_targ);
X       wl_sjl(linet1);
X       wl_sjl("FunnelWeb will leave both files intact so you can look at them.");
X       goto severe;
X      }
X   }
X
X /* Tell everyone that we have written a product file. */
X /* Note that we use the macro name. The full name is usually too messy. */
X sprintf(linet1,"Tangle: Completed %s.",&p_ma->ma_name[0]);
X wl_sjl(linet1);
X return;
X
X /* Jump here is a nasty file error occurs. */
X severe:
X sprintf(linet1,"A problem occurred during the generation of product file \"%s\".",&fn_targ[0]);
X wl_sjl(linet1);
X wl_sjl("S: Aborting...");
X num_sev++;
X return;
X
X}
X
X/******************************************************************************/
X
XEXPORT void tangle()
X{
X name_t dummyname;
X p_ma_t p_ma;
X
X /* Possibly decrease tglinmax if W option is turned on. */
X if (option.op_w_b)
X    tglinmax=MIN(tglinmax,option.op_w_i);
X
X /* Some compilers do not allow much space for statics so we allocate fn_targ */
X /* dynamically to save static space.                                         */
X fn_targ=(char *) mm_temp(sizeof(fn_t));
X
X /* Generate each file contained in the file table. */
X tb_fir(file_table);
X while (num_sev==0 && tb_rea(file_table,PV dummyname,PV &p_ma))
X    ex_file(p_ma);
X}
X
X/******************************************************************************/
X/*                               End of TANGLE.C                              */
X/******************************************************************************/
X
END_OF_FILE
if test 18625 -ne `wc -c <'sources/tangle.c'`; then
    echo shar: \"'sources/tangle.c'\" unpacked with wrong size!
fi
# end of 'sources/tangle.c'
fi
echo shar: End of archive 9 \(of 20\).
cp /dev/null ark9isdone
MISSING=""
for I in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 ; do
    if test ! -f ark${I}isdone ; then
    MISSING="${MISSING} ${I}"
    fi
done
if test "${MISSING}" = "" ; then
    echo You have unpacked all 20 archives.
    rm -f ark[1-9]isdone ark[1-9][0-9]isdone
else
    echo You still need to unpack the following archives:
    echo "        " ${MISSING}
fi
##  End of shell archive.
exit 0