[josephg]

I'm not a latex expert. I don't know what the difference is between tex math, latex math and amsmath is. (And please don't explain it, I don't care.) Maybe there are some weird expressions out there that don't have a typst equivalent, if we really looked for them. But I haven't run into anything myself, despite writing a pretty math-heavy CS paper. (Or at least, the early drafts were math heavy.)

> I'm not interested in a programming language (though naturally being able to write plugins would be useful ala luatex), but a textual macro system.

Are you sure? Because latex macros like that are really horrible to read & write, and latex gives you notoriously hard to read error messages for your trouble. Here's the equivalent in typst:

    #let dt(x) = $(∂#x) / (∂t)$

In my opinion, this is way more readable. That code defines a lambda function (like arrow functions in javascript) that returns a "math mode" block ($this is a math block$). #x escapes the math block to evaluate x - which is just the function parameter we defined earlier.

And you'd use it simply:

    The result is $dt(y)$

Its not a macro system. Its just a function that you can call anywhere - including from other functions. And the function returns a block. I personally think its much nicer, and more familiar than the latex macro equivalent.

[aragilar]

I'm curious, how does typst work out that I want the function expanded or I want the literal string if there's no marker.

[lapinot]

There are 3 syntactic modes in typst: markup, code and math. In markup, everything is literal, unless you put a `#` sigil like `#expr` in which case `expr` is parsed in code mode. In code mode everything is an identifier, as usual in programming. In math its a bit of an ugly tradeoff but its ok: single-letter things are parsed as literals but multi-letter tokens are parsed as identifiers. Finally, in code you can enclose in `[...]` to parse in markup mode. So typically, your document will be mostly in markup mode and you will encounter stuff like `#something[An argument]`, which is a function call to which you pass one content-typed argument.

So above, `y` is parsed as literal, while `dt` is parsed as an identifier, hence function call.

[teo_zero]

> In markup, everything is literal, unless you put a `#` sigil

Unless it's a "=", then it begins a new section. And unless it's a "-" or a "+" or a "/", then it's a list item. And unless it's a "<", then it defines a label, or a "@", then it's a reference to one. And unless it's a "_" or "*" or "`", then it changes font or style.

[josephg]

Right. Markup mode supports markup features - including all of that stuff for headings, lists, bold, italics and so on. It’s clearly inspired by markdown and similar languages. Personally I prefer * to \em{xxx} since it’s easier to type and it makes the text easier to read while I’m editing. (Or maybe just more familiar since give written so much markdown at this point).

[aragilar]

I think I would have preferred a consistent sigil, but I guess with fast enough feedback you'd get used to the quirks.

I do wonder if this has over-optimised on short equations—to me heavy maths use implies multi-page equations with very specific formatting requirements (something amsmath has no issues with, which isn't surprising given who the authors are).