Show HN: Conway's Game of Life in TypeScript's type system

In the typescript playground, the best way to see the output of any evolution number is to have it autocomplete a string literal!

Uncomment one of the PGunXX types that you want to see, then below it type this:

    const boardstr: PGun10 = ``;

Then put the cursor inside the two backticks and press Control+Space for intellisense autocomplete, and press enter on the first entry there. Then intellisense will put the computed board into a string literal, looking like:

    const boardstr: PGun10 = `............................................
    ........................xx..................
    ........................x..x................
    ..........x.x...............x......xx.......
    ........x...x..xxx..........x......xx.......
    .xx.....x...................x...............
    .xx....x....x.......xx..x..x................
    ........x.......x.x..x..xx..................
    ........x...x.....xxx.......................
    ..........x.x...............................
    ............................................`;

SO many ways.

In college I did it in assembler (a couple hundred bytes of code) on a PDP11/34 and displayed the results on an oscilloscope screen :)

At this point, TypeScript should just let us define types using plain imperative TS code that will execute during static analysis. Might as well.

type MyType = someFunc(T)

Of course these functions might be typed too…

Any sufficiently capable type system will make it possible to implement a form of functional programming.

These advanced type systems are essentially a form of pre-compile time scripting to assert certain guarantees about user defined types. It's the same mechanism that makes C++ templates turing complete.

I recently had the insight- surely induced by reading something on HN or listening to some podcast- that types are simply functions from the set of all possible "values" to a logical value...