The LaTeX cargo cult

Once again I will try to be clear: Knuth's work resulted in a computer program, TeX, as an EXE file, say, tex.exe.

A user of TeX as a word processor types in a file with three letter extension TEX, say, my_math.tex. This file, my_math.tex, actually is a computer program, that is, has allocate-free storage, if-then-else, file read-write, arithmetic, string manipulations, etc. This computer program my_math.tex is not Knuth's program tex.exe.

Yes, maybe not all TeX users have their TeX input files, say, my_math.tex, do file reading or writing, but such file manipulations are just routine usage of TeX that I do nearly always. And I have some TeX macros I wrote that do storage allocation-freeing. Maybe not all TeX users do such things, but they are routine usage of TeX, and I do them.

To be more clear on just why file my_math.tex is a computer program, when Knuth's tex.exe runs file my_math.tex (interpretively), the program my_math.tex can read files. Then the output my_math.dvi can vary depending on what was in the file, say, my_math.dat that program my_math.tex read.

Well, there can be no file my_math.htm that will read a file my_math.dat, that is, read the file and process it like my_math.tex can.

So, if only for this reason, as a result, program my_math.tex can never be translated to a file my_math.htm. And program my_math.tex can't be translated to my_math.pdf or my_math.ps either.

But a file my_math.dvi, from my_math.tex and a particular my_math.dat, can be translated to a file my_math.pdf or my_math.ps.

And in this thread I have been suggesting that there could be a program that would translate my_math.dvi to my_math.htm.

> TeX -> PDF can be done without an intermediate DVI stage using pdftex.

Although this is a small point, for pdftex, I am quite sure that internally a DVI file is generated if only because that is what Knuth's program tex.exe generates and rewriting Knuth's TeX code, likely now in C, say, tex.c, would be both unnecessary and the difficult approach. Just generating the DVI file is the easy approach, even if don't have the user aware of the intermediate DVI file.

What PDFTEX does I do frequently by putting in the extra step of going to DVI and then from DVI to PDF. Fine.

I want the DVI file because I like the DVI preview program I have and like it much more than than using a PDF viewer. When I get something that looks good with my DVI preview program, then usually I go ahead and make the PDF file.

However, what I am doing getting a PDF file and what you are talking about with pdftex are not, in the sense I am discussing, a translation of TeX to PDF. Not at all.

> Any reasoning about TeX being able to do things that HTML can't is irrelevant.

True for what you are talking about. False for my point that a file my_math.tex can't be translated to a file my_math.htm.

Or, for a short explanation, you are saying that a file my_math.dvi can be translated to file types PS and PDF and maybe also HTM, and I agree. But I am also saying that a file my_math.tex cannot ever be translated to a file my_math.htm.

To be still more clear, HTML is a mark-up language, and TeX looks like it is also a mark-up language, so one might try to translate TeX mark-up to HTML mark-up. Well, such a translation is just impossible, and will always be.

How do I tell CSS that I want my bibliography to be sorted by author last name, and have the inline citations be of the form (Author, Year), except when I'm using the author's name in the text as a noun, in which case it should be just "Author (Year) showed that blah blah blah"? For that matter, I don't think CSS can even do justification properly (by properly, I mean not treating each line as an independent unit, but shifting text around within an entire paragraph to minimize deviation from the desired inter-word spacing globally). I know someone implemented TeX's algorithm in Javascript once upon a time, but I'm willing to bet it's not any faster than TeX.

I have no real argument against the idea that you could build something that does everything LaTeX does just as well. Clearly you can. I am arguing that LaTeX has a huge amount of really important things already built in, and people use those things every single day. You have to (a) have all that stuff ready on day one if you want people to use a new thing, and (b) getting from where you are today to that point will necessarily involve taking the nice clean thing that seems so much nicer than LaTeX and making it messier, uglier, and more complex. The only thing that makes Markdown, for instance, nice for people to use is that it only does a handful of common things, so it can make those common things simple and conventional. Bold to bold something. (Amusing and apropos to the topic, HN's version of Markdown appears to not allow me to type star-starBoldstar-star. Not with backslashes or any other way I can find). If you want to build a LaTeX clone though, you need to decide: what's going to be the simple, easy-for-people convention we use to denote "don't put a line break here, because these two characters are someone's initials" and "stack these equations in a group, centered on the equal signs, and include the individual equations on lines 1, 3, 5, and 8 in the global numbering of equations, but not the others." You're going to have to define a stylesheet of some sort to govern the rendering engine's myriad options (do I indent the first line of a paragraph, or should everything be left-aligned, but with extra vertical space between paragraphs).

CSS is arguably already uglier, messier, and more complex, and while I'm sure it's improving all the time, as of about five years ago, I think the entire internet was almost exclusively composed of porn and articles about how to center something vertically, in roughly equal proportion. Epub is an HTML+CSS based format specifically geared at the kind of thing that you'd need, and just like every other technology we're mentioning, it's terrible unless you're doing left-to-right, top-to-bottom, figure-less, table-less, text where formatting doesn't matter. Just like CSS3, we can say, Epub3 supports more stuff now! Someone let me know when it's safe to buy ebooks with code samples in them instead of getting the paper version.