Drawdown preview package

Atom plugin for visualizing markdown files with drawdown diagrams in it.

Plugin relies on the drawdown parser and drawdown renderer which are build especially for the purposes of this plugin, but already live their own live as npm modules.

Drawdown syntaxis

The syntax of the drawdown language is pretty simple and its main goal is to be as human readable as possible.

Header

All drawdon diagrams are parsed form markdown code block and need to have a header in the format drawdown.<diagram-type>.<diagram-identifier

Example

```drawdown.flow.particle-trap
  ...
  ...

```

In the example above we declared flow diagram called particle-trap.

Flow diagrams

Currently flow diagrams consist of two different type of blocks you can use:

Process block

Process blocks are represented by a simple rectangular shape and we can declare them by typing:

- Catch the particle.

Conditional block

Conditional blocks are represented by a diamond shape and we can declare them by typing:

- Particle is positive?

You will notice all blocks start with - token and end either with full stop . or question mark ? followed by new line.

Example

```drawdown.flow.particle-trap

- Catch the particle.
- Particle is positive?

```

This will prodice the following diagram:

Arrow labeling

We can label an arrow by using a special token called CASE token. Its syntax is as follows - <label>:

Example

- Yes:

Branching the flow

In order to branch several flow paths (arrows) from a block all we have to do is to use an arrow label (a CASE token) and indentation for the consequential blocks:

- Yes:
  - Branched block.
- No:
  - Another Branched block.
- Maybe:
  - Third branch.
  - The third branch follows.

Example

```drawdown.flow.particle-trap

- Catch the particle.
- Particle is positive?
- Yes:
  - It is a proton.
  - Store it in a positive charge trap.
- No:
  - It is an electron.
  - Store it in a negative charge trap.

```

There are several things we should know:

1. The actual indentation size is not important as long as it is consistent over the branch.
2. Tokens of type CASE can have any label we want: - Yes:, - No:, - Negative:, - Positive:, etc.
3. We can branch as many branches as we want, but arrows will start to look awkward.

Graph diagrams

This diagrams represent general graphs and their syntax is ridiculously simple:

```drawdown.graph.entanglement

electron ~~ proton
proton ~~ neutron
electron ~~ neutron
up quark ~~ proton
down quark ~~ proton
up quark ~~ neutron
down quark ~~ neutron
```

This will produce something like

Arrows

We have several types of arrows which we can use

We can have arrow labels by placing a text between the arrow's token style symbols:

```drawdown.graph.quantum-teleportation
Alice ~~ Alice
Alice ~loves~> Bob
Bob ~knows~> Alice
Bob ~~> Charlie
Charlie ~never sees~> Bob
Charlie ~chats with~> Alice
```