The library structure

One of the things that makes papis interesting is the fact that its library structure is nearly nonexistent.

A papis library is linked to a directory, where all the documents are (and possibly sublibraries). What papis does is simply to go to the library folder and look for all subfolders that contain a information file, which by default is a info.yaml file.

Every subfolder that has an info.yaml file in it is a valid papis document. As an example let us consider the following library

├── folder1
│   └── paper.pdf
├── folder2
│   ├── folder3
│   │   ├── info.yaml
│   │   └── blahblahblah.pdf
│   └── folder4
│       ├── info.yaml
│       └── output.pdf
├── classics
│   └── folder5
│       ├── info.yaml
│       └── output.pdf
├── physics
│   └── newton
│       └── principia
│           ├── document.pdf
│           ├── supplements.pdf
│           └── info.yaml
└─── rpa
    └── bohm
        ├── info.yaml
        ├── notes.tex
        └── output.pdf

The first thing that you might notice is that there are many folders. Just to check that you understand exactly what is a document, please think about which of these pdfs is not a valid papis document… That’s right!, folder1/paper.pdf is not a valid document since the folder1 does not contain any info.yaml file. You see also that it does not matter how deep the folder structure is in your library: you can have a physics folder in which you have a newton folder in which you have a folder containing the actual book document.pdf plus some supplementary information supplements.pdf. In this case, inside the info.yaml you would have the following file section

- document.pdf
- supplements.pdf

which tells papis that this folder contains two relevant files.