[NTG-context] TeX syntax -- a guide?
Thomas A. Schmitz
thomas.schmitz at uni-bonn.de
Thu Feb 25 22:39:37 CET 2010
On Feb 25, 2010, at 9:39 PM, James Fisher wrote:
> After a few days working in "do what the tutorials say" mode, I now want to understand TeX from a programmer's mindset. I have not been able just by practise to work out what the syntactic rules of TeX are, and I am hoping that there is a sensible guide to this somewhere. However, searches for things like "tex syntax" draw a blank. Some of the things I want to understand, for example, are: (1) what is the distinction between square brackets and curly brackets after a command? (2) Why are there sometimes lists of square-bracketed lists after a command, each with lists of seeming arguments inside them? (2) What exactly are the "variables" in a TeX file? (I've seen variable-like things sometimes referred to just plainly, sometimes with preceding backslashes as if they were commands/macros). (4) Why can't I end a square-bracketed section with a final square-bracket on a line of its own, as I may do in other programming languages? (5) How are things like \subsection, \subsubsection, \subsubsubsection, ... implemented? I am used to languages in which there is only a finite set of commands; why is the logic here not more like \section[level=1], \section[level=2], ... ? (6) Perhaps I'm misunderstanding things and all this isn't actually the fundamental syntax of TeX but just adhoc syntax defined by various macros doing different things -- is this the case; to what degree can macros define syntax?
> Obviously I don't expect answers to all these here, but can someone point me to somewhere on the 'net that could answer them? The only other possibilities I can see are buying an expensive copy of the TeXbook, etc.
First, you're confusing two things: TeX syntax and ConTeXt syntax. Most of what you're asking here has to do with the way ConTeXt implements things. For starters, I would recommend http://wiki.contextgarden.net/Inside_ConTeXt, especially the overview about System Macros.
But if you want to actually write your own macros (or simply understand the way ConTeXt works) you will indeed need some understanding of TeX. Complaining about the price of the TeXbook doesn't sit very well with most TeXies (most of us think the price is reasonable, we're using this incredibly software for free, and if you're really poor, you can always go to a library), but there's an absolutely wonderful book which you can download for free, TeX by topic, http://eijkhout.net/texbytopic/texbytopic.html Personally, I find it more accessible than the TeXbook.
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