# doc-gen4
Document Generator for Lean 4

## Usage
You can call `doc-gen4` from the top of a Lake project like this:
```sh
$ /path/to/doc-gen4 Module
```

where `Module` is one or more of the top level modules you want to document.
The tool will then proceed to compile the project using lake (if that hasn't happened yet),
analyze it and put the result in `./build/doc`.

You can optionally provide the path to a `LeanInk` binary using the `--ink` flag which will make
the tool produce `Alectryon` style rendered output along the usual documentation.

You could e.g. host the files locally with the built-in Python webserver:
```sh
$ cd build/doc && python -m http.server
```

### Multi stage
You can also use `doc-gen4` in multiple separate stages to generate the whole documentation.
For example `mathlib4` consists out of 4 modules, the 3 Lean compiler ones and itself:
- `Init`
- `Std`
- `Lean`
- `Mathlib`
The first stage in the build is:
```sh
$ doc-gen4 init Mathlib
```
We already have to pass the `Mathlib` top level module here so it can generate the
navbar on the left hand side properly in the index and 404 HTML pages.
Next we can run the actual build stages:
1. `doc-gen4 single Init Mathlib`
2. `doc-gen4 single Std Mathlib`
3. `doc-gen4 single Lean Mathlib`
4. `doc-gen4 single Mathlib Mathlib`
We have to pass `Mathlib` here again for the same reason, the single command
will only generate documentation for its first argument module. Furthermore
one can use the `--ink` flag here to also generate LeanInk documentation in addition.
The last stage is the finalize one which zips up some information relevant for
the search:
```sh
$ doc-gen4 finalize
```
Now `build/doc` should contain the same files with the same context as if one had run
```
$ doc-gen4 Mathlib
```