diff options
Diffstat (limited to 'Master/texmf-dist/source/latex/l3kernel/l3tl.dtx')
-rw-r--r-- | Master/texmf-dist/source/latex/l3kernel/l3tl.dtx | 43 |
1 files changed, 29 insertions, 14 deletions
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3tl.dtx b/Master/texmf-dist/source/latex/l3kernel/l3tl.dtx index f5a36e95bad..cfe96ac73af 100644 --- a/Master/texmf-dist/source/latex/l3kernel/l3tl.dtx +++ b/Master/texmf-dist/source/latex/l3kernel/l3tl.dtx @@ -35,7 +35,7 @@ % %<*driver|package> \RequirePackage{l3names} -\GetIdInfo$Id: l3tl.dtx 2665 2011-08-25 22:15:27Z joseph $ +\GetIdInfo$Id: l3tl.dtx 2686 2011-08-29 19:41:06Z joseph $ {L3 Experimental token lists} %</driver|package> %<*driver> @@ -66,18 +66,25 @@ % \maketitle % % \begin{documentation} -% -% \LaTeX3 stores lists of token in variables also called \enquote{token lists}. -% Variables of this type get the suffix |tl| and functions of this type -% have the prefix |tl|. To use a token list variable you simply call -% the corresponding variable. -% -% Often you find yourself with not a token list variable but an -% arbitrary token list which has to undergo certain tests. We will \emph{also} -% prefix these functions with |tl|. While token list variables are -% always single tokens, token lists are always surrounded by -% braces. Many of the functions for token lists and token list variables -% are very similar, and so are grouped together here. +% +% \TeX{} works with tokens, and \LaTeX3 therefore provides a number of +% functions to deal with token lists. Token lists may be present direct in +% the argument to a function: +% \begin{verbatim} +% \foo:n { a collection of \tokens } +% \end{verbatim} +% or may be stored for processing in a so-called \enquote{token list +% variable}, which have the suffix \texttt{tl}: +% the argument to a function: +% \begin{verbatim} +% \foo:N \l_some_tl +% \end{verbatim} +% In both cases, functions are available to test an manipulate the lists +% of tokens, and these have the module prefix \texttt{tl}. +% In many cases, function which can be applied to token list variables +% are paired with similar functions for application to explicit lists +% of tokens: the two \enquote{views} of a token list are therefore collected +% together here. % % A token list can be seen either as a list of \enquote{items}, % or a list of \enquote{tokens}. An item is whatever \cs{use_none:n} @@ -85,7 +92,15 @@ % with optional leading explicit space characters (each item is thus % itself a token list). A token is either a normal \texttt{N} argument, % or | |, |{|, or |}| (assuming normal \TeX{} category codes). -% Functions which act on items are often faster than their analog acting +% Thus for example +% \begin{verbatim} +% { Hello } ~ world +% \end{verbatim} +% contains six items (\texttt{Hello}, \texttt{w}, \texttt{o}, \texttt{r}, +% \texttt{l} and \texttt{d}), but thirteen tokens (|{|, \texttt{H}, \texttt{e}, +% \texttt{l}, \texttt{l}, \texttt{o}, |}|, \verb*| |, \texttt{w}, \texttt{o}, +% \texttt{r}, \texttt{l} and \texttt{d}). +% Functions which act on items are often faster than their analogue acting % directly on tokens. % % \section{Creating and initialising token list variables} |