# Gargantext Purescript

## About this project

Gargantext is a collaborative web platform for the exploration of sets
of unstructured documents. It combines tools from natural language
processing, text-mining, complex networks analysis and interactive data
visualization to pave the way toward new kinds of interactions with your
digital corpora.

You will not find this software very useful without also running or being
granted access to a [backend](https://gitlab.iscpif.fr/gargantext/haskell-gargantext).

This software is free software, developed by the CNRS Complex Systems
Institute of Paris Île-de-France (ISC-PIF) and its partners.

## Development

### System Dependencies

* NodeJS (11+)
* Yarn (Recent)
* A webserver (anything that can serve a static directory will do)

#### NodeJS Installation

On debian testing, debian unstable or ubuntu:

```shell
sudo apt update && sudo apt install nodejs yarn
```

On debian stable:

```shell
curl -sL https://deb.nodesource.com/setup_11.x | sudo bash -
sudo apt update && sudo apt install nodejs
```

(For Ubuntu)
```shell
curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
sudo apt update && sudo apt install yarn
```

To upgrade to latest version (and not current stable) version, you can use
(Use n module from npm in order to upgrade node)

```shell
sudo npm cache clean -f
sudo npm install -g n
sudo n stable
sudo n latest
```


### OSX
```shell
brew install node
```

#### Yarn installation

On ubuntu:

```shell
curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
sudo apt update && sudo apt install yarn
```

On Mac OS (with Homebrew):

```shell
brew install yarn
```

#### Webservers

Some options:

* The `python3` builtin webserver 
* Caddy

### Purescript and Javascript dependencies

Once you have node and yarn installed, you may install deps with:

```shell
yarn install && yarn install-ps
```

### Development

You can compile the purescript code with:

```shell
yarn compile
```

Or run a repl:

```shell
yarn repl
```

```shell
yarn install && yarn ps-deps
```

### Running a dev server

```shell
yarn dev
```

This will launch a hot-reloading development server with
webpack-dev-server.  Visit [localhost:9000](http://localhost:9000/) to
see the result when the output shows a line like this:

```
ℹ ｢wdm｣: Compiled successfully.
```

#### Purescript IDE integration

A `purs ide` connection will be available on port 9002 while the
development server is running.

A guide to getting set up with the IDE integration is beyond the scope
of this document.

#### Source maps

Currently broken. Someone please fix them.

### Getting a purescript repl

```shell
yarn repl
```

### Compiling styles

We use the `sass` compiler for some of the style files. To convert them to CSS do:

```shell
yarn sass
```

### Building for production

```shell
yarn build
```

It is *not* necessary to `yarn compile` before running `yarn build`.

You can then serve the `dist` directory with your favourite webserver.

Examples:

* `python3 -m http.server dist`

<!-- To get a live-reloading development server -->

<!-- ```shell -->
<!-- yarn live -->
<!-- ``` -->

Note that a production build takes a little while.

### How do I?

#### Change which backend to connect to?

Edit `Config.purs`. Find the function `endConfig'` just after the
imports and edit `back`. The definitions are not far below, just after
the definitions of the various `front` options.

Example (using `demo.gargantext.org` as backend):

```
endConfig' :: ApiVersion -> EndConfig
endConfig' v = { front : frontRelative
               , back  : backDemo v  }
```

## Note to the contributors

Please follow CONTRIBUTING.md

### How do I?

#### Add a javascript dependency?

Add it to `package.json`, under `dependencies` if it is needed at
runtime or `devDependencies` if it is not.

#### Add a purescript dependency?

Add it to `psc-package.json` without the `purescript-` prefix.

If is not in the package set, you will need to read the next section.

#### Add a custom or override package to the local package set?

You need to add an entry to the relevant map in
`packages.dhall`. There are comments in the file explaining how it
works. It's written in dhall, so you can use comments and such.

You will then need to rebuild the package set:

```shell
yarn rebuild-set
```

#### Upgrade the base package set local is based on to latest?

```shell
yarn rebase-set && yarn rebuild-set
```

This will occasionally result in swearing when you go on to build.

## Theory Introduction

Making sense of out text isn't actually that hard, but it does require
a little background knowledge to understand.

### N-grams

N-grams are at the heart of how Gargantext makes sense out of text.

There are two common meanings in the literature for n-gram:
- a sequence of `n` characters
- a sequence of `n` words

Gargantext is focused on words. Here are some example word n-grams;

- `coffee` (unigram or 1-gram)
- `need coffee` (bigram or 2-gram)
- `one coffee please` (trigram or 3-gram)
- `here is your coffee` (4-gram)
- `i need some more coffee` (5-gram)

N-grams are matched case insensitively and across whole words. Examples:

| Text         | N-gram       | Matches              |
|--------------|--------------|----------------------|
| `Coffee cup` | `coffee`     | YES                  |
| `Coffee cup` | `off`        | NO, not a whole word |
| `Coffee cup` | `coffee cup` | YES                  |

You may read more about n-grams [on wikipedia](https://en.wikipedia.org/wiki/N-gram).

<!-- TODO: Discuss punctuation -->

Gargantext allows you to define n-grams interactively in your browser
and explore the relationships they uncover across a corpus of text.

Various metrics can be applied to n-grams, the most common of which is
the number of times an n-gram appears in a document.

## Glossary

document
: One or more texts comprising a single logical document
field
: A portion of a document, e.g. `title`, `abstract`, `body`
corpus
: A collection of documents
n-gram/ngram
: A word or words to be indexed, consisting of `n` words.
  This technically includes skip-grams, but in the general case
  the words will be contiguous.
unigram/1-gram
: A one-word n-gram, e.g. `cow`, `coffee`
bigram/2-gram
: A two-word n-gram, e.g. `coffee cup`
trigram/3-gram
: A three-word n-gram, e.g. `coffee cup holder`
<!-- skip-grams are not yet supported -->
<!-- skip-gram -->
<!-- : An n-gram where the words are not all adjacent -->
<!-- k-skip-n-gram -->
<!-- : An n-gram where the words are at most distance k from each other -->


