1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
|
\input plainpkg
\ProvidesPackage{actcodes}[2012/11/07 v0.2a active characters (UL)]
%%
%% Copyright (C) 2012 Uwe Lueck,
%% http://www.contact-ednotes.sty.de.vu
%% -- author-maintained in the sense of LPPL below --
%%
%% This file can be redistributed and/or modified under
%% the terms of the LaTeX Project Public License; either
%% version 1.3c of the License, or any later version.
%% The latest version of this license is in
%% http://www.latex-project.org/lppl.txt
%% There is NO WARRANTY (actually somewhat experimental).
%%
%% Please report bugs, problems, and suggestions via
%%
%% http://www.contact-ednotes.sty.de.vu
%%
%% == Purpose and Usage ==
%% The package derives from switching category codes
%% in the 'nicetext' and 'morehype' bundles and should
%% improve them.
%%
%% === Installing and Calling ===
%% The file `actcodes.sty' is provided ready,
%% installation only requires
%% putting it somewhere where \TeX\ finds it
%% (which may need updating the filename data
%% base).\urlfoot{ukfaqref}{inst-wlcf}
%% However, the files `plainpkg.tex' and `stacklet.sty' %% stacklet 2012/09/19
%% must be installed likewise.
%%
%% \emph{With} \LaTeX, the file should be loaded by `\RequirePackage{actcodes}'
%% or `\usepackage{actcodes}'.
%%
%% \emph{Without} \LaTeX, load it by `\input actcodes.sty'.
%%
%% As explained in `plainpgk-doc.pdf', however, ``generic"
%% packages based on 'plainpkg' should load 'actcodes' by
%% `\RequirePackage{actcodes}'.
%%
%% === Commands and Syntax ===
%% \label{sec:actcodes-cmds}
%% 'actcodes.sty' provides \ |\MakeActive|, |\MakeActiveAss|,
%% |\MakeActiveDef|, |\MakeActiveLet|,
%% |\MakeOther|, |\MakeActiveOther| \ with rather obvious
%% syntax---you find more detailed descriptions
%% mixed with implementation below ... TODO
%% ---Without \LaTeX, the latter's internal |\@gobble<arg>|
%% is provided as well.
%%
%% == The Code ==
%% === Our Private Letters ===
\PushCatMakeLetterAt
%%
%% === The Core ===
%% |\MakeActiveAss<ass-fun>\<char><ass-args>| ``activates" <char>
%% and then applies assignment function <ass-fun> with arguments
%% <ass-args> to it. The code derives from \LaTeX's
%% `\@sverb' and `\do@noligs' and was also discussed
%% on the \acro{LATEX-L} mailing list September 2010
%% (Will Robertson; Heiko Oberdiek).
%% The present definition generalizes
%% `\MakeActiveDef' and `\MakeActiveLet' of my earlier packages.
\gdef\MakeActiveAss#1#2{%
\MakeActive#2%
\begingroup \lccode`\~`#2\relax \lowercase{\endgroup #1~}}
%% I was reluctant to provide |\MakeActive\<char>|,
%% but with 'catchdq.sty', it would be better ... %% 2012/09/16
\gdef\MakeActive#1{\catcode`#1\active}
%% ... it just ``revives" the meaning that the corresponding
%% active-character token last time ...
%%
%% === \cs{def} and \cs{let} ===
%% |\MakeActiveDef\<char><parameters>{<replace>}|
%% has been employed in 'fifinddo' and 'blog'
%% (which is based on 'fifinddo') so far.
\gdef\MakeActiveDef{\MakeActiveAss\def}
%% W.r.t.\ the definition of this `\MakeActiveDef',
%% Heiko Oberdiek remarked that it allows \emph{macro parameters},
%% as opposed to my earlier definition in 'fifinddo'.
%% Without parameters, this kind of macro has been used for
%% conversion of text encodings ('atari.fdf',
%% and I thought this was the idea of \ctanpkgref{stringenc} ...).
%%
%% |\MakeActiveLet\<char><cmd>| has been provided in 'niceverb' so far.
%% The present package has been made in order to have
%% `\MakeActiveLet' with 'blog.sty' as well, it was too annoying
%% to use `\MakeActiveDef' there so often.
\gdef\MakeActiveLet{\MakeActiveAss\let}
%%
%% === Switching Back \textellipsis ===
%% Sometimes, the ``active" behaviour of <char> is too difficult,
%% and you may want to switch bach to its ``simple" way ...
%% This may work by |\MakeOther\<char>| ...
%% with \LaTeX, `\MakeOther' just is `\@makeother' ...
\ifltx \global\let\MakeOther\@makeother
\else \gdef\MakeOther#1{\catcode`#112\relax}
\fi
%% But within a macro (or other) argument, you can't change the `\catcode'.
%% (I~lost some time by not realizing that it was within a large argument
%% where I tried to switch the `\catcode'.)
%% Anyway or in certain cases, it may be better to keep a character
%% ``active" throughout a document and just to change the \emph{expansion}
%% of the ``active-character token." This can be done with
%% `\MakeActiveLet' and `\MakeActiveDef' in certain cases already.
%% E.g., when the \emph{``blank space"} has been ``activated" by
%% `\obeylines', `\MakeActiveLet\ \space' ``undoes" this half-way,
%% while it does not restore ``argument skipping" and
%% ``compressing blank spaces."
%%
%% When character <char> should be ``active" for some time,
%% but for certain moments you prefer that it behaves like an
%% ``other character", you can switch to its ``other" expansion by
%% |\MakeActiveOther\<char>|:
\gdef\MakeActiveOther#1{%
\MakeActiveAss\edef#1{\expandafter\@gobble\string#1}}
%% `\MakeActiveOther' uses \LaTeX's |\@gobble<arg>|,
%% \emph{without} \LaTeX, 'actcodes' provides it:
\ifltx\else \long\gdef\@gobble#1{} \fi
% \show_ \MakeActiveOther\_ \show_ \expandafter\show_
%% I am \emph{not} providing a version \emph{without}
%% the `\catcode' change, although the latter is superfluous here
%% TODO ...
%%
%% `niceverb' also provides |\MakeNormal\<char>|, it may migrate %% |...| 2012/11/07
%% to here in the future, and there may be |\MakeActiveNormal\<char>|
%% extending the above `\MakeActiveOther' TODO ...
%%
%% Also, a \emph{stack} might be used as in 'stacklet',
%% even to switch \emph{meanings} of active-character tokens ...
%% not sure TODO ...
%%
%% \ctanpkgref{babel} does similar things, but I never have ... TODO
%%
%% === Leaving and Version History ===
\PopLetterCatAt
\endinput
%%
%% VERSION HISTORY
v0.1 2012/08/26 started, almost completed
2012/08/27 completed; realizing \Push...At ..., bug fixes
v0.2 2012/08/28 \global\let, \def -> \gdef
2012/09/16 \MakeActive
2012/09/19 doc.: stacklet
v0.2a 2012/11/07 doc.: |...| on \MakeNormal
|
