Show2.lua: a small library for showing LaTeXed LaTeX code

In 2022 I made two videos - here: Pict2e-lua and Eev-TikZ - about how I was using Lua and eepitch to create LaTeX diagrams incrementally using REPLs. Here are two screenshots:

They both use this 3-window setting,

.______________________
|          |           |
|          | [t]arget  |
|          |  buffer   |
|  [e]dit  |___________|
|          |           |
|          |  [v]iew   |
|          |  the PDF  |
|__________|___________|

in which at the left half there's the Lua program that I am editing, at the upper right there's a target buffer running a Lua REPL, and at the lower right there's a buffer viewing the resulting PDF. These are some commands with very short names that I use very often,

• `M-x e' to go to the file that I am editing,
• `M-x v' to view the current PDF with pdftools,
• `M-x D' to view the current PDF in full-screen mode,

so it was natural to define a function called (etv) that would create that 3-window setting. I used it like this:

("a \\cdot b"):show()
* (etv)

Here the "a \\cdot b" is a very small chunk of LaTeX code. The line with the "show" does the first part of showing it as a PDF, and the (etv) does the rest: the :show() produces a PDF, and the (etv) creates a 3-window setting and displays the current version of the PDF in its lower left part. In short, what happens is this:

"a \\cdot b" | | :show() | v /DIR/outer.pdf | v ___________ | | | | | [t] | | [e] |_____| | | | | | [v] | |_____|_____|

We can expand it into the diagram below. Running ("a \\cdot b"):show() creates an object of the class Show, so let's start with

s = Show.new("a \\cdot b")

to store that object into a variable s. We have:

Show.bigstr =     "a \\cdot b"
                       |
                       | s:prep("d")
                       v
Show.bigstr =    "$a \\cdot b$"
                       |
                       | s:write()
                       v
s:innertex() =   /DIR/inner.tex
                       :
                       : /DIR/outer.tex contains this line:
                       :  \input inner.tex
                       v
s:outertex() =   /DIR/outer.tex
                       |
                       | s:compile() runs this:
     s:cmd() =         |  cd /DIR/ && lualatex outer.tex
                       v
s:outerpdf() =   /DIR/outer.pdf
                       |
                       | * (etv)
                       v
                   ___________
                  |     |     |
                  |     | [t] |
                  | [e] |_____|
                  |     |     |
                  |     | [v] |
                  |_____|_____|

(TODO: explain the rest; explain globals; explain code-etv2)

elpeg