Getting Started

What you need

Nothing to install: the playground runs in the browser. Type on the right and the figure is drawn on the left as you go.

To run it locally, clone the repository and run:

npm install
npm run dev

The docs open on port 5173 and the playground on 5174.

Your first figure

Every program starts by bringing in the prelude — the definitions of point, line, circle and the rest:

import prelude

Then name things, and say how they relate. A right triangle with legs 3 and 4:

import prelude

triangle t with a b c
a at 0 0
b at 3 0
c at 0 4

triangle t with a b c makes the triangle and names its corners; the next three lines put them in place. Leave one out — delete c at 0 4 — and c is drawn wavy: the program no longer says where it is.

Say it with lengths instead, and Tilde works out the rest:

import prelude

triangle t with a b c
distance between a and b is 3
distance between b and c is 4
distance between c and a is 5

Now c could be on either side of ab, so both places are drawn.

Next steps

• Elements — points, lines, circles, segments, triangles
• Constraints — everything you can say about them
• Reading a Line — how Tilde reads what you write
• Solver — how Tilde figures out where things go