user202729

.some notes.

Why TeX, as a programming language, is so hard?

There are some issues with TeX. Not that it's a expansion language.

It has a few quirks in behavior that will take you hours of debugging if you don't know them in advance.

Part 1. Preprocess as text

grab all rest of document
rescan with synctex kept (only possible in LuaLaTeX)
as string, can do anything

Part 2. Catcode

Why are brace hacks so complicated?

It's not complicated. In fact, given what you want to do in TeX, and in combination with how the other primitives work, brace hacks is the simplest way to implement the engine.

(basically, as Knuth writes both TeX the engine and plain.tex, the engine tend to be made simpler if some "trick" suffices to achieve a functionality instead of adding another primitive to the engine)

First brace hack, `\bgroup/\egroup`

The motivation of this brace hack is simple -- one example is described in the TeXbook:

Use sympytex on overleaf

This is not officially supported, but you can made it to work...

first, see the test.tex file below (because of an annoying GitHub gist "bug", all files following a large raw file are shown as "cannot display file this big...", thus the "a-" prefix)
download sympy.zip attached below in the gist, and upload it to your overleaf.

Put this as your TeX file

\documentclass{article}
\usepackage{shellesc}

%\usepackage{fancyvrb}
%\usepackage{fvextra}
%\fvset{breaklines=true, breakanywhere=true}

	// ==UserScript==
	// @name Typer.io - No input limit
	// @namespace blob
	// @version 0.0.1
	// @match https://typer.io/*
	// @grant none
	// @run-at document-end
	// ==/UserScript==

	'use strict';

	from dataclasses import dataclass
	from typing import Any

	from gdb_call_lambda import get_gdb_expression_from_value


	class EmptyPrinter:
	def to_string(self):
	return "{}"

	[luatex - LaTeX3 versus pure Lua - TeX - LaTeX Stack Exchange](https://tex.stackexchange.com/questions/45183/latex3-versus-pure-lua?noredirect=1&lq=1)

	String N
	scan token
	etc.

	// moreflags=-std=c++17
	#if not LOCAL
	#define NDEBUG 1
	#endif
	#include<bits/stdc++.h>
	#include<variant>

	using std::variant;
	using std::in_place_type;