Nicer warning messages

[ucwmac.git] / ucwmac.tex

diff --git a/ucwmac.tex b/ucwmac.tex
index 87c0b4608ac2cbc83a85d371aa5e06992f2f44bf..61b2103f4f384f4ec99aebb9e58343c90ae08c3f 100644 (file)
--- a/ucwmac.tex
+++ b/ucwmac.tex
@@ -35,7 +35,17 @@
 \long\def\prependef#1#2{\expandafter\def\expandafter#1\expandafter{#2#1}}
 \long\def\appendef#1#2{\expandafter\def\expandafter#1\expandafter{#1#2}}
 
-\def\ucwwarn#1{\immediate\write16{*** Warning: #1 ***}}
+% Variants of \def and \let, where the control sequence name is given as a string
+\def\sdef#1{\expandafter\def\csname#1\endcsname}
+\def\slet#1#2{\expandafter\let\csname#1\expandafter\endcsname\csname#2\endcsname}
+
+% Add \protected to an existing macro
+\def\addprotected#1{\protected\edef#1{\expandafter\unexpanded\expandafter{#1}}}
+
+% Protect ~
+\addprotected~
+
+\def\ucwwarn#1{\immediate\write16{*** UCWmac warning: #1 ***}}
 
 %%% Page size and margins %%%
 
@@ -231,12 +241,17 @@
 \newbox\itembox
 \newcount\itemcount
 
+% Penalties (changed at compatibility level 1)
+\newcount\preitemizepenalty    \preitemizepenalty=0
+\newcount\postitemizepenalty   \postitemizepenalty=0
+
 \def\preitemize{
        \ifitems
                \vskip\prenesteditemizeskip
                \advance\leftskip by \nesteditemindent
                \advance\rightskip by \nesteditemnarrow
        \else
+               \ifnum\preitemizepenalty=0\else\penalty\preitemizepenalty\fi
                \vskip\preitemizeskip
                \advance\leftskip by \itemindent
                \advance\rightskip by \itemnarrow
@@ -248,6 +263,7 @@
        \ifitems
                \vskip\postnesteditemizeskip
        \else
+               \ifnum\postitemizepenalty=0\else\penalty\postitemizepenalty\fi
                \vskip\postitemizeskip
        \fi
 }
@@ -310,17 +326,24 @@
 % \putimage{width specification}{file}
 \def\putimage#1#2{\hbox{\pdfximage #1{#2}\pdfrefximage\pdflastximage}}
 
-% Let ~ be protected
-\let\plaintilde=~
-\protected\def~{\plaintilde}
-
 %%% Colors %%%
 
+% Use of pdfTeX color stack:
+% \colorpush\rgb{1 0 0} puts a new color on the stack
+% \colorset\rgb{1 0 0} replaces the top color on the stack
+% \colorpop pops the top color
+% \colorlocal\rgb{1 0 0} set a color locally until the end of the current group
 \chardef\colorstk=\pdfcolorstackinit page direct{0 g 0 G}
-\def\colorpush#1{\pdfcolorstack\colorstk push{#1 rg #1 RG}}
-\def\colorpushgray#1{\pdfcolorstack\colorstk push{#1 g #1 G}}
-\def\colorpushcmyk#1{\pdfcolorstack\colorstk push{#1 k #1 K}}
+\def\colorset#1{\pdfcolorstack\colorstk set #1}
+\def\colorpush#1{\pdfcolorstack\colorstk push #1}
 \def\colorpop{\pdfcolorstack\colorstk pop}
+\def\colorlocal{\aftergroup\colorpop\colorpush}
+
+% Different ways of describing colors: \rgb{R G B}, \gray{G}, \cmyk{C M Y K}
+% (all components are real numbers between 0 and 1)
+\def\rgb#1{{#1 rg #1 RG}}
+\def\gray#1{{#1 g #1 G}}
+\def\cmyk#1{{#1 k #1 K}}
 
 %%% Localization %%%
 
@@ -357,6 +380,27 @@
        \expandafter\let\csname ucwmod:#1\endcsname=\relax
 }
 
+% Compatibility levels
+% We try to be backwards compatible as much as we can, so all changes in behavior
+% (except for addition of new control sequences) are versioned. By default, ucwmac
+% starts in compatibility level 0, which should produce the same results as historic
+% versions of ucwmac. Use \ucwcompat{level} to upgrade to a given level, or if you
+% do not care about compatibility, \ucwcompat\ucwmaxcompat.
+
+\chardef\ucwcurrentcompat=0    % Currently active compatibility level
+\chardef\ucwmaxcompat=1                % Maximum supported compatibility level
+
+\def\ucwcompat#1{
+       \ucwcurrentcompat=#1
+       \ifcase #1
+               % Level 0 (default): old ucwmac
+       \or     % Level 1
+               \preitemizepenalty=-500
+               \postitemizepenalty=-500
+       \else\errmessage{Unsupported compatibility level #1 requested.}
+       \fi
+}
+
 %%% Epilog %%%
 
 % Let's hide all internal macros