The viewer

The viewer has two panels. The left panel (biblo) shows each class as a card. At first, a card shows only the boundary of its class: its parent, its cells and its methods. The right panel (canvas) holds instances.

How to use it

1. Drag a class name from the top of a card to the canvas. Or focus the name and press Enter. The viewer makes a subclass, for example Text_1, and an instance of it.
2. Click ▸ to expand an instance, and ▾ to collapse it. The detail select of each panel sets the number of levels that show their full view. At level 2 of the type graph, each method is a formula on one line.
3. Click a value on the canvas to edit it. The edit also becomes the new cell of the subclass, and its card shows it.
4. Click a formula to edit a method as text. Or expand it, and click an op, a path or a literal. Each instance of the class renders with the new method at once.
5. Select data on a canvas item to see its dehydrated value. An edit in the data view goes back to the item.
6. Hover a child to see its controls: move it earlier, move it later, or remove it. The + menu of the last child adds a child without a drag.
7. Type in the filter at the top of the type graph to filter the cards. Edit the name of a class in its card to rename it.

Undo and redo (Ctrl+Z and Ctrl+Shift+Z) take back each change and apply it again. The viewer records each action, and undo replays the record without the last action. The viewer saves the record in the browser, with the level of each panel and the instances that you expanded. Thus a reload keeps the session. Export saves it as a file, and import opens a file.

The counter in the canvas header shows the nodes that the last action evaluated, and the nodes in the store. An item flashes when the action evaluated one of its nodes. A badge shows the nodes on a dependency cycle.

The chip of a class shows the traits that apply to it, for example Point for a class with the cells x and y. Below the cards, the type graph lists each trait with its cells and its methods, and the atoms of the view.

Safe edits

An edit in a card that gives an invalid class goes back, and a notice tells why. For example, drop a class into the arguments of a method. A class instance is not an expression, thus the viewer refuses the change. A standard class keeps its name. Reset gives the standard classes and an empty canvas again, and undo brings the old state back.

The viewer is also a standalone app: pnpm dev starts it at the root of the repository.