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diff --git a/Master/texmf-dist/tex/generic/genmisc/ragged.sty b/Master/texmf-dist/tex/generic/genmisc/ragged.sty new file mode 100644 index 00000000000..909de8695ce --- /dev/null +++ b/Master/texmf-dist/tex/generic/genmisc/ragged.sty @@ -0,0 +1,781 @@ + + %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + %%%% ragged.sty by Laurent Siebenmann, March 1996 -- + %% beta version of Mar 30, 1996. + %% Aim: Maintain hyphenation and raggedness control + %% while providing the following for all formats. + %% --- to make a paragraph ragged on left and justified + %% on right, use the syntax + %% \raggedL <paragraph> + %% --- to make a paragraph ragged on both left and right + %% (and symmetric), use the syntax + %% \raggedC <paragraph> + %% \raggedR is essentially equivalent \raggedright of Plain + %% or to \RaggedRight of raggedri.sty of G. Schr"oder. + %% All three \raggedX should give the same linebreaks; they + %% just provide different horizontal positioning of the lines. + %% Documentation of options etc. follows \endinput. + %% Run this file alone to see a demo. + + \ifx\undefined\raggedL\else\expandafter\endinput\fi + + \chardef\raggedcatAT=\catcode`\@ \catcode`\@=11 + + %%temporarily suppress Plain's logging of allocations + \let\R@Gtemp\wlog + \def\wlog#1{\relax} + + \newbox\R@Gvbox + \newbox\R@Ghbox + \newbox\R@Ghbox@ + + \newcount\R@Glinect + + \newskip\R@Gfillskip + + \newdimen\R@Gauxdim + \newdimen\R@Gindentdim + \newdimen\R@Ghsize + \newdimen\raggedStretch + + \raggedStretch=10\p@ %% default + + \newtoks\raggedEnv + \newtoks\raggedEnvOnce + + \let\wlog\R@Gtemp + + \R@Gfillskip=\z@ plus 1fil + + %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + %%%% Core macros + + \def\R@Gprep{\ifhmode + \errmessage{ Do not use + \noexpand\raggedX commands in horizontal mode}% + \expandafter\par\fi} + + \def\R@Gcore{% + \setbox\R@Gvbox=\vbox\bgroup + \hsize=\maxdimen \leftskip=\z@ + \hskip\z@skip} + + \def\CalcR@GIndent@{% + %% first set \R@Gindentdim to excess of \R@Ghsize over remainder + \R@Gindentdim=\hsize + \advance\R@Gindentdim by -\rightskip + \advance\R@Gindentdim by -\wd\R@Ghbox@ + %% second convert to hang as l,c,r demand + \fixR@Ghang@ %% \R@Gindentdim=.5\R@Gindentdim for \raggedC + }% + + \def\endR@Gcore{\endgraf + \global\R@Glinect=\prevgraf + \global\setbox\R@Ghbox=\lastbox + \egroup % + \ifcase\R@Glinect\relax %% 0 + \or \endR@Gcore@ %% 1 + \else \errmessage{\noexpand\raggedX is failing. + Read about \string\RaggedX}\endR@Gcore@ %% >1 + \fi} + + \def\endR@Gcore@{% + \setbox\R@Gvbox=\vbox{% + \unhcopy\R@Ghbox\unpenalty\unskip\unskip + \endgraf\global\R@Glinect=\prevgraf %\showthe\prevgraf + \global\setbox\R@Ghbox@=\lastbox}% + \setbox\R@Ghbox@=\hbox{% + \unhbox\R@Ghbox@\unpenalty\unskip\unskip}% + \CalcR@GIndent@ %% + \ifdim\R@Gindentdim>\z@ + \hangindent=\R@Gindentdim %\showthe\R@Gindentdim + \else + \hangindent=\z@ + %% Rmk: neg hangindents are from right margin + \fi + \advance\R@Glinect by -1\relax + \hangafter\R@Glinect + \unhbox\R@Ghbox + \endgraf} + + \def\endR@@G{\endR@Gcore\let\par\R@Goldpar\endgroup} + + \def\raggedFrac#1{\def\R@GFrac{#1 }} + + \raggedFrac{1} %% default + + \def\R@GEnv@{% + %\parskip=4pt plus 1pt + %\baselineskip=12pt + %\parfillskip=0pt plus 1fil + %\emergencystretch=20pt + \finalhyphendemerits=20000 % 5000 is Plain default + \parindent=\z@ %% 0 + \pretolerance=\@M %% 10000 + %% end of options easily changeable + %% via \raggedEnv{...} and \raggedEnvOnce{...} + \let\R@Goldpar\par + \let\par\endR@@G + \R@Gauxdim=\hsize + \advance\R@Gauxdim by -\leftskip + \advance\R@Gauxdim by -\rightskip + \R@Ghsize=\R@GFrac\R@Gauxdim + \advance\R@Gauxdim by -\R@Ghsize + \R@GRedefs + \the\raggedEnv + \the\raggedEnvOnce\global\raggedEnvOnce{}% + }% + + \def\R@GRedefs{\let\break\R@Gbreak + \let\vadjust\R@Gvadjust@ + \everydisplay{\R@Geverydisplaymole@}} + + \def\R@Gnono{ is forbidden with \string\raggedX} + \def\R@Gbreak{\errmessage{\noexpand\break\R@Gnono}\penalty-\@M}% + \def\R@Gvadjust@#1{{\tt (USE OF vadjust)}% + \errmessage{\noexpand\vadjust\R@Gnono.\space See output}}% + \def\R@Geverydisplaymole@#1$${$${\tt (DISPLAY)}% + \errmessage{Display math\R@Gnono. See output}}% + + \def\raggedHrule{\unskip\penalty0 + \vrule height0.3\p@ depth-0\p@ width \R@Ghsize \penalty0}% + + %%% \R@GEnv@@ corrects \R@Ghsize if user has modified it + %% through \leftskip, \rightskip via \raggedEnv{...} + %% then does other last minute tasks tasks + \def\R@GEnv@@{% + \R@Ghsize=\hsize + \advance\R@Ghsize by -\leftskip + \advance\R@Ghsize by -\rightskip + \parfillskip=\R@Gfillskip + } + + %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + %%%% User macros + + %%% \raggedC + \def\raggedC{\R@Gprep\begingroup + \leftskip=1\leftskip \rightskip=1\rightskip + \R@GEnv@ + \advance\leftskip by .5\R@Gauxdim plus .5\raggedStretch + \advance\rightskip by .5\R@Gauxdim plus .5\raggedStretch + \def\fixR@Ghang@{\R@Gindentdim=.5\R@Gindentdim}% + \R@GEnv@@ + \R@Gcore} + + %%% \RaggedC + \def\RaggedC{\R@Gprep\begingroup\let\R@Gcore\relax + \let\R@GRedefs\relax\raggedC + \parfillskip=\z@ + \def\par{\let\par\R@Goldpar\par\endgroup\endgroup}% + } + + % %%% \raggedR@ is strict analog of \raggedR@, \raggedC@ + % %% present for testing only + % \def\raggedR@{\R@Gprep\begingroup + % \R@GEnv@ %% not needed + % \advance\rightskip by \R@Gauxdim plus \raggedStretch + % \def\fixR@Ghang@{\R@Gindentdim=0\p@}% + % \R@GEnv@@ + % \R@Gcore + % } + + %%% \raggedR is more robust then \raggedL, \raggedC as it + %% it allows $$...$$ and \vadjust, \break etc. in paragraph. + \def\raggedR{\R@Gprep\begingroup + \let\R@GRedefs\relax + \R@GEnv@ %% initial part + \advance\rightskip by \R@Gauxdim plus \raggedStretch + \R@GEnv@@ + \def\par{\let\par\R@Goldpar\par\endgroup}% + } + + %%% \RaggedR + \def\RaggedR{\R@Gprep\raggedR + \parfillskip=\z@\relax} + + \def\raggedL{\R@Gprep\begingroup + \R@GEnv@ + \advance\leftskip by \R@Gauxdim plus \raggedStretch + \def\fixR@Ghang@{}% + \R@GEnv@@ + \R@Gcore} + + %%% \RaggedL + \def\RaggedL{\R@Gprep\begingroup\let\R@Gcore\relax + \let\R@GRedefs\relax\raggedL + \parfillskip=\z@ + \def\par{\let\par\R@Goldpar\par\endgroup\endgroup}% + } + + \def\gobble#1{} + + \catcode`\@=\raggedcatAT + + %%%% END INPUT IF THIS IS NOT A DEMO RUN ! + \edef\temp{\csname\jobname\endcsname}% + \edef\Temp{\csname ragged.sty\endcsname}% + \ifx\temp\Temp\else + \expandafter\endinput + \fi + + %%%% END OF MACROS + %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + %%%% BEGINNING OF DEMONSTRATION + %%% TESTS FOR \raggedX + + \ifx\documentstyle\undefined + \let\documentstyle\gobble \let\begin\gobble + \fi + \documentstyle{article} + \begin{document} + + \hsize=400pt + + \raggedStretch=1000pt + \RaggedC + THESE ARE TESTS FOR ragged.sty\break + EXPORT THE TESTS BEFORE PLAYING WITH THEM + \bigskip + + \widowpenalty=10000 + \leftskip=0\hsize %plus 10pt + \rightskip=0\hsize %plus 10pt + \raggedStretch=10pt %% 10pt dafault + \raggedFrac{.5} + \raggedEnv{\parskip=4pt plus 3pt + \emergencystretch=20pt + %\pretolerance=100 + } + \parskip=0pt plus 2pt + \parindent=0pt + +\def\TESTTEXT{It is the union of passionate interest in detailed +facts with equal devotion to abstract generalization which forms +the novelty in \hbox{our present society}. } + + \TESTTEXT + + %\raggedEnvOnce{\raggedStretch=0pt} + \raggedL\raggedHrule + % $$dfd$$ %\vadjust{\hrule}% \break + \TESTTEXT + + \raggedL + {\sl A.N. Whitehead} + + \raggedC\raggedHrule\TESTTEXT + + %\raggedEnvOnce{\parskip=0pt} + \raggedC{\sl A.N. Whitehead} + + + \raggedR\raggedHrule\TESTTEXT + + \raggedR +{\sl A.N. Whitehead} + + %\end + %{document} + + %%%%%%%%%%%%%%%%%%%%%%%%%%%% + %%% TESTS FOR \RaggedX + + \raggedStretch=1000pt %% default 10pt %% play with this + \raggedEnv{% + %\linepenalty=0 %% default 50 %% play with this + \parskip=4pt plus 3pt + %\pretolerance=0 %% default 100 + %\hyphenpenalty=0 %% default 50 + } + + \bigskip \hrule \bigskip + + \TESTTEXT + + \RaggedL\raggedHrule\TESTTEXT + + \raggedL +{\sl A.N. Whitehead} + + + \RaggedC\raggedHrule\TESTTEXT + + %\raggedEnvOnce{\parskip=0pt} + \raggedC{\sl A.N. Whitehead} + + + \RaggedR\raggedHrule\TESTTEXT + + \raggedR +{\sl A.N. Whitehead} + +\end +{document} + + %%%% END OF TESTS + %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + + + ***** USER DOCUMENTATION FOR ragged.sty ***** + + + + *** TYPICAL EXAMPLE + + \input ragged.sty + + \raggedFrac{.4} + \raggedEnv{\parskip=4pt plus 3pt} + \raggedL\raggedHrule +I was not a Child~Prodigy, because a Child~Prodigy is +a child who knows as much when it is a child as it +does when it~grows~up. + +\raggedL +{--- Will Rogers} + +The above will produce a quotation that is aligned to the right margin, +ragged on the left and having about .4 the width of a normal line. + + Just compose this file itself to see to see a more extensive +example instantly composed. + + + + *** INTENDED USES + +(i) For "ragged-left-and-flush-right" formatting of short prose +quotations tradionally placed at the end of book chapters. + +(ii) For captions on figures in an artistic page layout. + +(iii) For notes in a left hand margin ragged on the left and aligned +on the right. + + (iv) For "raggedleft" composition of left-hand pages of of narrow +brochures --- matching "raggedright" composition of right hand pages. + + Admittedly, hand specification of linebreaks is often the best +option, and that is how Don Knuth proceeds for use (i) in most of his +books. But in case reformatting for different page sizes or screen sizes +is anticipated, Knuth's alternative should be avoided like the plague; +this should apply to all documents distributed in ".tex" typescript +format. The last 3 applications seem to demand good control on +raggedness and hyphenation. + + + + *** NOVELTY + + It is too early to assert with confidence that ragged.sty offers +genuinely new capabilities in all formats. + + Hopefully \raggedL and \raggedC offer something new even for LaTeX +users. The standard "center" and "flushright" environments of LaTeX do +*roughly* the same thing by a different method. But the macros +\raggedL and \raggedC seem a necessery innovation in case one wants +control on raggedness and/or hyphenation. + + Outside LaTeX, even the offer even the more limited LaTeX features +are little known; thus, particularly sturdy macros \RaggedC and \RaggedL +are also offered by ragged.sty to provide just the LaTeX features in +other formats --- which means all features except raggedness control and +hyphenation. + + + + *** USER CONTROL SEQUENCE SUMMARY + +The \raggedX trio: +\raggedL <paragraph> %% sets paragraph ragged on left justified on right +\raggedC <paragraph> %% sets paragraph ragged on both left and right +\raggedR <paragraph> %% sets paragraph ragged on right justified on left +See also the companion trio \RaggedX below. + +With the default configuration, each of these leaves an arbitrarily +short last line while maintaining some tension on earlier lines +(\raggedStretch=10pt, total raggedness stretch). + +Only the following paragraph is affected by each. + + --- \raggedHrule provides a horizontal line of the ragged text width +if put *immediately after* \raggedX. + + --- \raggedFrac{<decimal fraction>} sets the length of the lines of +the ragged-set paragraphs as a fraction of current line length. +The current line length is + + (\hsize diminished by \leftskip and \rightskip) + + --- \raggedEnv{...} is to be placed before \raggedX; it allows the user +to redefine parameters for the line breaking environment of \raggedX. +Inspect the definition of the internal macro \R@GEnv@ for hints on +which parameters to change. Never change the code in ragged.sty; +your modifications belong in \raggedEnv{...} within your typescripts. + + \raggedEnv{...} and \raggedFrac{...} need not be repeated before +each use of \raggedX. If you want once-only temporary ragged +environment change, you can use grouping or \raggedEnvOnce{...} + + \raggedFrac, \hsize, \leftskip, \rightskip should not appear in the +argument of \raggedEnv; this is roughly because they relate to external +parameters. + + By default, paragraph indentation of the ragged paragraph is +zero. Hyphenation is by default switched off. However +\raggedEnv{\parindent=20pt \pretolerance=100} would change this back +to Plain defaults. + + You may want to adjust the new dimension \raggedStretch, which is +10pt by default. Incidentally, if the total stretch in lines falls +below about 20pt, you may have to add, say \emergencystretch=20pt +inside \raggedEnv{...}. + + In tuning stretch and hyphenation, consider also the following: +\fontdimen3\font=<dimension>, \spaceskip=<skip> and \xspaceskip=<skip>. +Cf. Plain's \raggedright. + + A companion trio \RaggedL, \RaggedC, \RaggedR are simpler, +robuster, and faster macros that perform two services already available +in LaTeX: + + (i) If used with default parameters, they force the last paragraph line +to have roughly the same length as all others. Results are good if +there are many lines. + + (ii) If used with parameter value \raggedStretch=1000pt, they behave +like the competing LaTeX environments with default parameters: lines are +relaxed and filled in natural order. + + + *** INSTALLATION + + For any format, \input ragged.sty will install the package. + + For LaTeX (version 2e), place \usepackage{ragged} in the article header +between \documentclass{...} and \begin{document}. + + + + *** OCCASIONAL PROBLEMS AND THEIR REMEDIES + + \raggedL and \raggedC (not \raggedR and \RaggedX) are only +moderately robust: they work correctly only when the paragraph contents +will form a single line if composed on an "infinitely" long line. +Therefore, they misbehave if they contain *for example* displayed math +or \break or material inserted by \vadjust; and also if the paragraph +exceeds about a page of typing; error warnings are given. + + The most annoying failing is the unavailability of \break; it can +be replaced by \hbox{...} and the tie ~ ; indeed without introducing the +inflexibility which \break does. + + Fortunately such limitations do not much interfere with the use +intended. (Indeed the unavailability of \break is a blessing in +disguise.) + + If difficulty is nevertheless encountered, use the *fast* and +*robust* \RaggedL and \RaggedC where necessary (search out "\Ragged" +instructions and tests!). + + On a given paragraph, all 3 \raggedX should always produce the +*same* linebreaks; any exception is a bug. Similarly for all three +\RaggedX. + + Please report undocumented bugs to lcs@topo.math.u-psud.fr. + + + + *** A TRIVIAL SOLUTION WHEN RAGGEDNESS IS NULL + + Donald Arseneau pointed out (Info-TeX, Sat Mar 9, 1996) that if +left and right margins are justified (i.e. \raggedStretch is zero) then +the last line of paragraphs can be center or right aligned by a simple +"trick" setting as follows: + + *** Center Alignment + + \leftskip=1\leftskip plus 1fil %% use \setlength in LaTeX + \rightskip=-\leftskip + \parfillskip=0pt plus 2fil + + *** Right Alignment + + \leftskip=1\leftskip plus 1fil %% use \setlength in LaTeX + \rightskip=-\leftskip + \parfillskip=0pt plus 1fil + +Donald considers this *well known*; he learned of it first from +Barbara Beeton. + + This device will also work in ragged environments IF AND WHEN +*extended* TeX allows skips to have *both* finite and infinite stretch +-- analogous to ordinals of the form integer + \omega. This is not +yet planned. + + As always in TeX, there may yet be another "deus ex machina"! Time +will tell. + + + + *** WHY USE ragged.sty WITH LATEX? + + LaTeX (in all versions) has the environments "flushleft", "center", +and "flushright" that perform very nearly the services of \RaggedL, +\RaggedC, and \RaggedR. LaTeX also has macros \raggedright and +\raggedleft roughly equivalent to "flushleft" and "flushright" minus +the grouping that goes along with an environment. + + These LaTeX environments/macros perform reliably, and like \RaggedX +do *not* suffer the fragility mentioned above for \raggedX. + + All these LaTeX features are programmed by a mare parameter setting +(cf. programmer documentation below): they simply use the infinite value +1fil for the stretch component of \leftskip and/or \rightskip, and this +permits quite excessive raggedness -- as testing shows. If one just +makes this stretch finite and modest, then the last line becomes +excessively stretched and/or all lines tend to become equal. This matter +seems to have been first recorded and remedied by Jan van der Steen and +Martin Schr\"oder who wrote raggedri.sty (1993) (see CTAN) producing a +macro \RaggedRight more or less equivalent to Plain's \raggedright -- +but no \RaggedCenter nor \RaggedLeft. + + Consequently LaTeX users have reason to use my macros \raggedL and +\raggedC when controlled raggedness is wanted. In addition, I suspect +the ragged.sty syntax will prove helpful in adjusting up width's and +margins. + + Since the competing LaTeX environments are deeply imbricated in +the complicated "list" environment apparatus, I have not attempted to +tinker directly with the LaTeX code to make the new ragged.sty features +a well integrated patch for LaTeX; that is a job for those working on +LaTeX3. + + + + *** HISTORY + + These macros were initially programmed to respond to a request of +Laszlo Battha <battha@apollo.ggki.hu>, Mon Mar 4, 1996 on the Info-TeX +list. + + Laurent Siebenmann + Math'ematique, Bat. 425, + Univ de Paris-Sud, + 91405-Orsay, + France + + + + + + + + %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + + + ***** PROGRAMMER DOCUMENTATION FOR ragged.sty ***** + + In essence, \RaggedX is a mere parameter setting; indeed, it sets +the stretch components of \leftskip and \rightskip to total +\raggedStretch. What is a miracle preordained by Knuth is that as +soon as \raggedStretch is huge (say 1000pt), while \linepenalty +remains substantial (say 50) all lines but the last are as full as +they can be without puting interword spaces under tension. +Hyphenation occurs only to prevent line length overrun. LaTeX +operates similarly but using infinite stretch. + + In contrast, \raggedL and \raggedC are hopefully original; they +are more devious than outright difficult; what will be more +difficult is to make them work in absolutely all circumstances where +Plain's \raggedright works. They already give perfect typography +or else complain. + + Permit me to set the scene with an overstatement. Analogs of all +three \raggedX exist in every competent wordprocessor since 1984 -- +beginning with MacWrite. However, in TeX (1982) there was an +unfortunate oversight; there should be not just one \parfillskip but +two: \leftparfillskip and \rightparfillskip=\parfillskip. These +should be "skip"s (elastic spaces) inserted at the left and right of +the last line of each paragraph. If these become available (say in +an e-TeX or Omega), one will be able to program \raggedL and +\raggedC by merely setting these parameters along with \leftskip, +\rightskip and a few others. + + This makes it clear that the moderately complicated programming +I have used is just a "workaround". Fortunately it is neither slow +nor bulky. + + Here is the logic of the present programming of \raggedL; it +will be followed by some promising alternatives. + + + + *** CURRENT METHOD (A) + + --- Sweep the paragraph text into \vbox of huge \hsize so that the +paragraph text fits on one line. The use of a \vbox instead of an +\hbox; here is the one recent "breakthrough" involved; it surfaced as a +result of investigations of Barbara Beeton, Michael Downes and Don +Knuth -- in this order! -- see TUGboat 11 (Nov 1991), pages 605--612. + + --- Extract the line as an \hbox and \unhbox it into a \vbox with +the "raggedleft" environment as desired, except for \parfillskip=0pt +plus 1fil where we would really want \leftparfillskip=0pt plus 1fil +and \rightparfillskip=0pt. Here we learn the number of lines in the +paragraph by use of \lastgraph. + + --- We find out the length of the the last line by using \lastbox to +pick off the last \hbox in the above \vbox, and then \unhbox'ing it +into another \hbox stripping off a penalty10000, \rightskip and +\parfillskip (going right to left). + + --- From this, we can calculate the indentation by which to push the +last box right to make it flush with the right margin. + + But we do *not* do that since it entails unpleasant technical +complications related to vertical placement. Instead we more +simply: + + --- unhbox onto the current page (essentially) the first \hbox +encountered above, using the last mentioned environment modified only by +a \hangindent equal to the measured indent, which is scheduled by +\hangafter to intervene on the last line of the paragraph. + + In a real sense the current page receives the final paragraph +just like a normal paragraph. Therefore (hopefully!) no vertical +mode complications will occur. + + Far *more* complex tricks of this sort, *the last one excepted*, are +exploited in Donald Arseneau's shapepar.sty on CTAN. Fortunately, +ragged.sty and shapepar.sty do not compete on the performance +front. + + + + *** ALTERNATIVE METHOD (B) + + This is the method I first attempted in a preliminary "hack" posted +on Info-teX Sat Mar 9, 1996. The raggedleft paragraph can contain +\vadjust and \break since the "one-long-line" requirement of (A) +disappears. + + --- first compose the paragraph \vbox with the ultimately desired +\hsize, \leftskip, \rightskip, but use \parfillskip=0pt plus 1fil. + + --- obtain the relaxed length of the last paragraph line much as +as above, using \lastbox etc. The last line is thus "deleted". + + --- reconstruct the last line as an \hbox to assure the correct +horizontal location. + + --- restore the last line into the \vbox. This requires careful +vertical placement, possibly involving \lastskip, \lastdepth, +\lastpenalty, + + --- \unvbox the corrected \vbox onto the current page. +This again requires careful vertical placement, eg. as regards +space both above and below, penalties etc. + + The last step requires that one be able to perfectly emulate, by +hand as it were, important parts of TeX's paragraph builder. It is by +far a more delicate task than the first method. Donald Arseneau called +it "painful" (Info-TeX, Sat Mar 9, 1996). + + Indentations above *displayed equations* have not been discussed +(but they are in alternative C below); that would redouble complexity. + + + + *** ALTERNATIVE METHOD (C) + + This last alternative is my proposed improvement of the first +method by use of an auxiliary file for storing widths between TeX +jobs and by possible use of two passes on each paragraph. + + This method seems to fully eliminate the failings of \raggedX, +ie. refusal of: displays, \break, \vadjust. Very desirable for a +narrow brochure with left-hand pages composed "raggedleft". But I +have done only fragmentary prototyping. + + Two passes on a paragraph are executed (when that is necessary) +by taking up the whole paragraph in a macro argument, storing it +temporarily in unexpanded token list form, and then rereading it so +that category assignments are those for normal progressive input. +This will be done by fast internal primitives in all versions of +e-TeX. But in Knuth's TeX it requires writing the unexpanded token +list out to a file, with help of the the \meaning primitive and +then rereading. + + An auxiliary file with indentation widths may indicate that a +preliminary pass is unnecessary; thus, on the average, composition +should be very fast. + + --- during a possible preliminary composition of a paragraph one +keeps \parfillskip equal 0pt plus 1fil, and merely records, in the +order of occurrence: + + (a) the widths of remainders on the last line before each display, +using \predisplaysize and a temporary addition to the token list +\everydisplay. + + (b) the width of the remainder on the paragraph's last line. This +is gotten using \lastbox much as in methods (A) or (B). + +Note that \lastbox operates in internal vertical mode, and not in +vertical mode. Hence all preliminary composition is to be done in a +\vbox. This \vbox is discarded once the necessary indentation +information has been extracted --- just as in method (A) but +contrary to method (B). + + --- during final raggedleft composition of a paragraph, the width +information is applied with help from \lastgraf, \hangindent, +\hangafter much as in method (A). + +In this final raggedleft composition of a paragraph, the width +information used may be either from the current job or from a +previous job. But it is always obtained from some preliminary +composition. + + In the case of a paragraph that is composed by \raggedL in a +single pass, it would be highly desirable to have a check that the +composed paragraph is OK; it would for example probably *not* be OK +if changes had intervened there since last composition. The +unavailability of \lastbox in ordinary vertical mode seems to make +a *sure* check difficult. Perhaps one must be content with checks +that are less than sure --- such as variation of the number of +typescript lines occupied by the paragraph as found via +\inputlineno. The user could also signal changes using a syntax like +\raggedL[changed 1647]. Also, \raggedTwoPass in the header could +force slow but sure two-pass treatment. + + + Incidentally, a simple way to make a brochure with left pages +raggedleft and right pages raggedright and *without* altering the +output routine is to compose the brochure twice, once raggedleft +and once raggedright; then one can mix the two at the .dvi (or +postscript) level. + + It is clear that, for such brochures, vertical spacing in and +among paragraphs should be perfectly normal, and identical for +raggedleft and raggedright composition. Method (C) seems to +promise this without pain. + + + + I recommend (C) as next method to program. But I could +be wrong. + + Laurent Siebenmann + Math'ematique, Bat. 425, + Univ de Paris-Sud, + 91405-Orsay, + France + + 30 March 1996 + + |