macros
How to make spaces as command argument delimiters?
\documentclass{article}
\newcommand\foo[2]{#1 and #2.}
\begin{document}
\foo hi you
\end{document}
The expected output is
hi and you.
Of course I don't want to enclose the arguments with curly braces.
The following is not what I am looking for.
\documentclass{article}
\def\foo #1 #2 {#1 and #2.}
\begin{document}
\foo hi you
\end{document}
You define the macro as
\def\startMyBuffer#1[#2]
{....}
To avoid the macro eating spaces, use
\def\startMyBuffer#1[#2]%
{...}
(Note the % at the end. You also have a trailing whitespace at the end of the next line. Thus, a proper definition of the macro is
\def\startMyBuffer#1[#2]%
{% Store the name --- we'll need it when defining stopMyBuffer
\def\myBufferName{#2}% <<<<---- ADDED THS
% ConTeXt macro that defines the \start... and \stop... commands.
\dostartbuffer[#2][startMyBuffer][stopMyBuffer]}
If you don't want to worry about all this, use \starttexdefinition ... \stoptexdefinition instead.
\starttexdefinition startMyBuffer #1[#2]
% Store the name --- we'll need it when defining stopMyBuffer
\def\myBufferName{#2}
% ConTeXt macro that defines the \start... and \stop... commands.
\dostartbuffer[#2][startMyBuffer][stopMyBuffer]
\stoptexdefinition
Trimming spaces can be difficult with kernel macros; here LaTeX3 can come to the rescue:
\documentclass[a4paper]{amsart}
\usepackage{tikz,xparse}
\tikzset{graph/.style = {every node/.style = { draw,
shape = circle,
fill = black,
minimum size = 0.8mm,
inner sep = 0mm,
label distance = 0.8mm
}}}
%%% We need a "classical" definition, because of the colons in the replacement text
\newcommand{\circumferencenodeinner}[4]{\node (#1#2) at (#4: #3) [label = #4: $#2$] {};}
%%% Now we go with LaTeX3
\ExplSyntaxOn
\NewDocumentCommand{\circumferencenode}{ O{} m m m }
{
\hammerite_circumference_node:nxnx
{ #1 }
{ \tl_trim_spaces:n { #2 } }
{ #3 }
{ \tl_trim_spaces:n { #4 } }
}
\cs_set_eq:NN \hammerite_circumference_node:nnnn \circumferencenodeinner
\cs_generate_variant:Nn \hammerite_circumference_node:nnnn { nxnx }
\ExplSyntaxOff
\newlength{\gr} % graph radius
\setlength{\gr}{15mm}
\begin{document}
\noindent\begin{minipage}{.4\textwidth}
%%% Just to give an example we use the old definition
\newcommand{\circumferencenodeold}[4][]{\node (#1#2) at (#4: #3) [label = #4: $#2$] {};}
\textbf{Old}
\begin{tikzpicture}[graph]
\circumferencenodeold{0}{\gr}{ 90}
\circumferencenodeold{1}{\gr}{ 30}
\circumferencenodeold{2}{\gr}{330}
\circumferencenodeold{3}{\gr}{270}
\circumferencenodeold{4}{\gr}{210}
\circumferencenodeold{5}{\gr}{150}
\draw (0) -- (1) -- (2) -- (3) -- (4) -- (5) -- (0);
\end{tikzpicture}
\vspace*{10mm}
\begin{tikzpicture}[graph]
\circumferencenodeold{02}{\gr}{ 90}
\circumferencenodeold{ 3}{\gr}{ 0}
\circumferencenodeold{ 4}{\gr}{270}
\circumferencenodeold{15}{\gr}{180}
\draw (02) -- (3) -- (4) -- (15) -- (02);
\end{tikzpicture}
\end{minipage}\vrule\qquad
\noindent\begin{minipage}{.4\textwidth}
\textbf{New}
\begin{tikzpicture}[graph]
\circumferencenode{0}{\gr}{ 90}
\circumferencenode{1}{\gr}{ 30}
\circumferencenode{2}{\gr}{330}
\circumferencenode{3}{\gr}{270}
\circumferencenode{4}{\gr}{210}
\circumferencenode{5}{\gr}{150}
\draw (0) -- (1) -- (2) -- (3) -- (4) -- (5) -- (0);
\end{tikzpicture}
\vspace*{10mm}
\begin{tikzpicture}[graph]
\circumferencenode{02}{\gr}{ 90}
\circumferencenode{ 3}{\gr}{ 0}
\circumferencenode{ 4}{\gr}{270}
\circumferencenode{15}{\gr}{180}
\draw (02) -- (3) -- (4) -- (15) -- (02);
\end{tikzpicture}
\end{minipage}
\end{document}
The command \circumferencenodeinner is defined in the standard way because of the colons in its replacement text; notice that no optional argument is specified; it's only a helper macro that will be \let to a macro with a LaTeX3 name, so that the variant with suffix nxnx can be created; the x means that the corresponding argument is completely expanded. Indeed when we finally call it, arguments #2 and #4 are passed to \tl_trim_spaces:n whose job is exactly to trim leading and trailing spaces, then passing the rest as is.
Best Answer
You can't do this with
\newcommand. But it's possible with\def:Now
\foo x y Somethingwill give the expected result. However this will break in cases such asbecause there's no space after
you(the end-of-line counts as a space only if not followed by another end-of-line, when they are transformed into\par).You can look in the TeXbook or in TeX by Topic for "delimited arguments".