\catcode`| = 13
\def|{\item {--}}
\def\itemize#1{{\leftskip = 40 pt #1 \par}}
\itemize{
| First item
| Second item
}
The above example from Latex Wikibook and I do not know what functionality {--} in the itemize provides. Does it have a special meaning?
Also I am confused about the double caret (^^) notation used at the beginning of the Catcodes section such as ^^K for superscript.
In another example there is a nested macro which is added below. It is said that double macro parameters ##n expand to #n, is this always the case?
> %% Required package.
\usepackage{ifthen}
%% TeX function that generates the language commands.
\def\localedef#1#2{
\ifthenelse{ \equal{\locale}{#1} }{
\selectlanguage{#2}
\expandafter\def\csname#1\endcsname ##1{##1}
}{
\expandafter\def\csname#1\endcsname ##1{}
}
}
%% Selected language. Can be placed anywhere before the language commands.
\providecommand\locale{fr}
%% Language commands.
\localedef{de}{ngerman}
\localedef{en}{english}
\localedef{fr}{frenchb}
%% ...
It is good that this page is comprehensive in the sense that a lot of topics are mentioned; however some subtle points are not explained lucidly. I think I should refer to some other source maybe TexBook to better understand the inner workings of TeX. Is there a introductory level short tutorial on TeX that I can use before consulting a more advanced source?
--ligatures see https://tex.stackexchange.com/questions/106131/how-do-i-know-which-ligatures-are-used-in-my-document on^^see https://tex.stackexchange.com/questions/62725/the-notation-in-various-engines on##https://tex.stackexchange.com/questions/71632/why-do-paramaters-of-renewcommand-need-to-double-up-the-within-a-foreach/71633#71633 – David Carlisle Apr 28 '17 at 00:22