Simon Willison’s Weblog

Aider. Aider is an impressive open source local coding chat assistant terminal application, developed by Paul Gauthier (founding CTO of Inktomi back in 1996-2000).

I tried it out today, using an Anthropic API key to run it using Claude 3.5 Sonnet:

pipx install aider-chat
export ANTHROPIC_API_KEY=api-key-here
aider --dark-mode

I found the --dark-mode flag necessary to make it legible using the macOS terminal "Pro" theme.

Aider starts by generating a concise map of files in your current Git repository. This is passed to the LLM along with the prompts that you type, and Aider can then request additional files be added to that context - or you can add the manually with the /add filename command.

It defaults to making modifications to files and then committing them directly to Git with a generated commit message. I found myself preferring the /ask command which lets you ask a question without making any file modifications:

The Aider documentation includes extensive examples and the tool can work with a wide range of different LLMs, though it recommends GPT-4o, Claude 3.5 Sonnet (or 3 Opus) and DeepSeek Coder V2 for the best results. Aider maintains its own leaderboard, emphasizing that "Aider works best with LLMs which are good at editing code, not just good at writing code".

The prompts it uses are pretty fascinating - they're tucked away in various *_prompts.py files in aider/coders.

# 3:26 am / python, ai, generative-ai, llms, ai-assisted-programming, claude-3-5-sonnet, aider

This month in Servo: parallel tables and more (via) New in Servo:

Parallel table layout is now enabled (@mrobinson, #32477), spreading the work for laying out rows and their columns over all available CPU cores. This change is a great example of the strengths of Rayon and the opportunistic parallelism in Servo's layout engine.

The commit landing the change is quite short, and much of the work is done by refactoring the code to use .par_iter().enumerate().map(...) - par_iter() is the Rayon method that allows parallel iteration over a collection using multiple threads, hence multiple CPU cores.

# 3:03 pm / concurrency, html, rust, servo

Build your own SQS or Kafka with Postgres (via) Anthony Accomazzo works on Sequin, an open source "message stream" (similar to Kafka) written in Elixir and Go on top of PostgreSQL.

This detailed article describes how you can implement message queue patterns on PostgreSQL from scratch, including this neat example using a CTE, returning and for update skip locked to retrieve $1 messages from the messages table and simultaneously mark them with not_visible_until set to $2 in order to "lock" them for processing by a client:

with available_messages as (
  select seq
  from messages
  where not_visible_until is null
    or (not_visible_until <= now())
  order by inserted_at
  limit $1
  for update skip locked
)
update messages m
set
  not_visible_until = $2,
  deliver_count = deliver_count + 1,
  last_delivered_at = now(),
  updated_at = now()
from available_messages am
where m.seq = am.seq
returning m.seq, m.data;

# 5:34 pm / message-queues, postgresql, sql, sqs, kafka