Why not put a space between commands and parameters?

Question

I hope this is just a matter of taste, but is there any reason not to separate a command from its first parameter with a space? (Or multiple parameters with intervening spaces for that matter.)

\chapter{Introduction}
\chapter {Introduction}

\setcounter{chapter}{2}
\setcounter {chapter} {2}

I like the second ones better. This makes prose more readable to me. I was wondering if this can get me into trouble, though.

Answer 1

The space after a command name is absorbed while parsing the command name and does not make a token at all. The space between the } { does make a character token, but space tokens are skipped when looking for macro arguments so it is fine to put in the spaces if you wish.

\setcounter {chapter} {2}

Note there is a difference between these spaces; if you go

\newcommand\foo{%
    \setcounter {chapter} {2}%
}

In that here, the space after \setcounter really isn't there in the definition of \foo but the space after {chapter} is there, there is a character token so TeX needs to record its value (32) and catcode (10) (although I have a feeling it optimises spaces somewhere, no doubt someone will post the exact line of tex.web) in any case the definition is one or two bytes bigger because of the space. It is unlikely that your documents are big enough that an extra byte will make you run out of memory, but this was a real issue when LaTeX was designed, which is why if you look at the sources of latex and most of the core packages you will see a coding style in which all removable braces and spaces are removed. That doesn't necessarily mean it's a good coding style now:-)