Simon Willison’s Weblog

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Friday, 1st March 2024

Streaming HTML out of order without JavaScript (via) A really interesting new browser capability. If you serve the following HTML:

<template shadowrootmode="open">
<slot name="item-1">Loading...</slot>
</template>

Then later in the same page stream an element specifying that slot:

<span slot="item-1">Item number 1</span>

The previous slot will be replaced while the page continues to load.

I tried the demo in the most recent Chrome, Safari and Firefox (and Mobile Safari) and it worked in all of them.

The key feature is shadowrootmode=open, which looks like it was added to Firefox 123 on February 19th 2024—the other two browsers are listed on caniuse.com as gaining it around March last year. # 4:59 pm

Endatabas (via) Endatabas is “an open source immutable database”—also described as “SQL document database with full history”.

It uses a variant of SQL which allows you to insert data into tables that don’t exist yet (they’ll be created automatically) then run standard select queries, joins etc. It maintains a full history of every record and supports the recent SQL standard “FOR SYSTEM_TIME AS OF” clause for retrieving historical records as they existed at a specified time (it defaults to the most recent versions).

It’s written in Common Lisp plus a bit of Rust, and includes Docker images for running the server and client libraries in JavaScript and Python. The on-disk storage format is Apache Arrow, the license is AGPL and it’s been under development for just over a year.

It’s also a document database: you can insert JSON-style nested objects directly into a table, and query them with path expressions like “select users.friends[1] from users where id = 123;”

They have a WebAssembly version and a nice getting started tutorial which you can try out directly in your browser.

Their “Why?” page lists full history, time travel queries, separation of storage from compute, schemaless tables and columnar storage as the five pillars that make up their product. I think it’s a really interesting amalgamation of ideas. # 4:28 am