Instructions

The package name is mojo-arrow. The Mojo import is arrow. The code generator command is gld-arrowgen-mojo.

Develop from this repository

Mojo is pinned to 1.1.0. Pixi installs it from the Modular channel. If that channel returns 401, put PREFIX_API_KEY in a local .env file and run the setup script again. Do not commit .env.

git clone https://github.com/leo-gan/gld-arrow.git
cd gld-arrow
bash scripts/ci-setup.sh
pixi run test

pixi run test compiles every file in tests/. pixi run check-generated regenerates tests/generated/ and diffs it. pixi run precompile writes .mojoc packages under /tmp/mojo-arrow-pkg.

Published package

The linux-64 package is on the prefix.dev channel leo-gan/leo-gan.

pixi add --channel https://prefix.dev/leo-gan/leo-gan mojo-arrow

That install provides arrow.mojoc and gld-arrowgen-mojo. It needs mojo-compiler 1.1.

Generate a struct

testdata/schema/message.json is a JSON Schema object. The generator also accepts an Arrow integration schema whose top-level key is fields, and an IPC stream or file whose schema message is the input. A schema metadata entry named title names the generated struct. Without that entry the name is Root.

pixi run mojo run -I src src/codegen/cli.mojo -- \
  --schema testdata/schema/message.json --out tests/generated

The struct Message has encoded_len, encode_to, and decode_from. encode_bytes returns one IPC stream that holds a single row.