Texcraft code by TeX section

This index maps the sections/chapters in Knuth's original TeX to the corresponding Texcraft code. This is not meant to be exhaustive in either direction, but rather a general guide.

Empty cells generally indicate that work on that section hasn't started.

Texcraft code is frequently annotated with the analogous TeX section (e.g. TeX.2021.855) and git grep can be used to find these annotations.

#	Name	Texcraft code
1	Introduction	N/A. This section defines global variables specific to the TeX Pascal code.
2	The character set	N/A. Texcraft uses Rust's Unicode character facilities.
3	Input and output	N/A. Texcraft uses Rust's stdlib for reading and writing files.
4	String handling	Largely N/A because Texcraft uses Rust's standard string facilities but some of this code is related to the string interner, which in Texcraft is in `collections/interner.rs` in `texcraft-stdext`.
5	On-line and off-line printing	N/A. Texcraft uses Rust's string formatting and printing facilities.
6	Reporting errors	The `error` module in `texlang` and `errormode.rs` in `texlang-stdlib`. See also the dedicated documentation on Texlang's error system.
7	Arithmetic with scaled dimensions	`common`
8	Packed data	N/A. Texcraft doesn't have any memory usage optimizations of this type.
9	Dynamic memory allocation	N/A. Memory allocation is done via Rust stdlib.
10	Data structures for boxes and their friends	`ds.rs` in `boxworks`
11	Memory layout	N/A. Memory allocation is done via Rust stdlib.
12	Displaying boxes	The `boxworks-lang` crate contains a DSL for box data structures. The format is different than in TeX. TeX's format can be parsed using code in `tex.rs` in `boxworks`.
13	Destroying boxes	N/A. Memory including boxes is managed by Rust.
14	Copying boxes	N/A. Copying is done via implementations of Rust's `Clone` trait.
15	The command codes	N/A. Texlang doesn't have global command codes. Texlang's command tags feature is used for cases when the command needs to be identified.
16	The semantic nest
17	The table of equivalents	N/A. Texlang's doesn't have a global table of state. Instead, the component pattern is used for per-command state.
18	The hash table	Mostly N/A because Texcraft uses Rust's stdlib data structures. But `command/map.rs` in `texlang` is the equivalent thing. The hash table is related to string interning, which in Texcraft is in `collections/interner.rs` in `texcraft-stdext`.
19	Saving and restoring equivalents	Implemented via `collections/groupingmap.rs` in `texcraft-stdext`.
20	Token lists
21	Introduction to the syntactic routines	N/A. This section is essentially just documentation.
22	Input stacks and states	The stacks are in `Internal` in `vm/mod.rs` in `texlang`. Error context is provided using Texlang's token tracing system, `token/trace.rs` in `texlang`.
23	Maintaining the input stacks	The stacks are modified throughout the `vm` module in `texlang`.
24	Getting the next token	`token/lexer.rs` and `vm/streams.rs` (especially the function `next_unexpanded`) in `texlang`.
25	Expanding the next token	`vm/streams.rs` in `texlang`, especially the `next_expanded` function.
26	Basic scanning subroutines	The `parse` module in `texlang`. In particular the `Parsable` trait determines what can be "scanned" and implementations of this trait generally map to subroutines in this section.
27	Building token lists
28	Conditional processing	`conditional.rs` in `texlang-stdlib`.
29	File names
30	Font metric data	`tfm`.
31	Device-independent file format	`dvi`.
32	Shipping pages out	`boxworks-dvi` (planned).
33	Packaging
34	Data structures for math mode
35	Subroutines for math mode
36	Typesetting math formulas
37	Alignment
38	Breaking paragraphs into lines	`boxworks-knuthplass`.
39	Breaking paragraphs into lines, continued	`boxworks-knuthplass`.
40	Pre-hyphenation	`boxworks-hyphenation` (planned).
41	Post-hyphenation	`boxworks-hyphenation` (planned).
42	Hyphenation	`boxworks-hyphenation` (planned).
43	Initializing the hyphenation tables	`boxworks-hyphenation` (planned).
44	Breaking vertical lists into pages
45	The page builder
46	The chief executive
47	Building boxes and lists
48	Building math lists
49	Mode-independent processing	Various modules in `texlang-stdlib`. E.g. `\advance` is implemented in `math.rs`.
50	Dumping and undumping the tables	Implemented by Texlang's serializable VMs feature which has dedicated documentation. The Texlang framework code for serding is in `vm/serde.rs` in `texlang`, but serialization code is spread throughout the project (e.g. `#[derive(Serialize)]` on any component type).
51	The main program
52	Debugging
53	Extensions