Solid · guide

Use a part before the reply is over

Solid says when one part of a reply is finished, which is before the whole reply is. So a screen can use the seats while the reason is still being written.

Install it

pnpm add @niscorp/solid zod

Step 1 of 3

The shape

The schema is the shape you asked the model for. Solid needs it before any text arrives.

The shape

import { z } from 'zod';
import { createStream } from '@niscorp/solid';

const Suggestion = z.object({
  show: z.string(),
  seats: z.array(z.string()),
  price_cents: z.number(),
  why: z.string(),
});

Step 2 of 3

One part of the stream

select gives you a stream of one part, by its path. It has the same on, onFinal and final as the whole.

onFinal is called once: when the name of the next key has been read, or when the list or object around the part closes. For an item of a list that is when the next item begins.

One part of the stream

const stream = createStream({ schema: Suggestion });
let piece = 0;

stream.select('seats.0').onFinal((seat) => console.log('piece', piece, '· first seat finished:', seat));
stream.select('seats').onFinal((seats) => console.log('piece', piece, '· seats finished:', seats));
stream.onFinal(() => console.log('piece', piece, '· the reply finished'));

Step 3 of 3

The pieces

The same reply as before, in four pieces. Parts finish in the order the model writes them, which is usually the order of the schema you gave it. Put first what the screen needs first.

The pieces

const pieces = ['{"show":"The Tem', 'pest","seats":["C4",', '"C5"],"price_cents":76', '00,"why":"Row C."}'];
for (const text of pieces) {
  piece += 1;
  stream.write(text);
}

Then

Run it.

Both are said in the third piece: the first seat because the second seat began, the list because the price was named. The reply is finished one piece later.

Run it

npx tsx parts.mts

It prints

piece 3 · first seat finished: C4
piece 3 · seats finished: [ 'C4', 'C5' ]
piece 4 · the reply finished