Largo

A scripting language whose runtime is a persistent object database.

Largo is a Python-ish scripting language with an unusual property: its entire runtime — every value, every live task, every stack frame — lives in a transactional database on disk at all times. Pull the plug mid-execution and the system resumes exactly where it left off. No checkpointing. No save/restore logic. No crontabs.

Tasks run cooperative async style, suspending on time, I/O, or data changes. A suspended task consumes no CPU or memory — it simply sits on disk until its condition is met, then resumes.

For more information see largolang.org or here for the full language reference.

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Installation

pip install largolang           # core
pip install largolang[llm]      # + Ollama support for LLM primitives
pip install largolang[telegram] # + httpx for Telegram primitives
pip install largolang[all]      # everything

Getting Started

After installation, run with:

largo

If there is an init.largo file in the current directory, it will run that (every time, so be sure it's idempotent). This file must provide certain built-ins which the largo compiler relies on, so be sure to clone the package init.largo as a starting point if you go this route. By default it will load the one shipped with largo.

There is no prompt (because stdout is a mashup of debugging output at this stage), but you can enter single-line statements to largo's stdin--most usefully import statements.

See Ostinato for some sample largo code.

Crufy console:

Type ctrl-C or /quit to exit. Hit enter to see if there are any pending console questions. Type "# - answer" to answer a console question, as in "2 - yes". /ls and /cd are cryptic and dangerous debugging commands. Use at your own risk. Anything not an answer or slash command is parsed as a one-line statement and spawned, but the output is not printed by default so wrap in a print() if you want to see the output. Console questions are asked with ask_root(question).

Try this (copy-paste to largo stdin):

print("Your favorite color is {ask_root("What's your favorite color?")}")

Then (after hitting return a few times to see how it works) answer with, e.g., "1 - blue".

Syntax highlighting

A Vim syntax file (largo.vim) is included in the package. To install it, find it in the package and copy it to (or symlink it from) ~/.vim/syntax

pip show largolang | grep Location          # Where the package lives
cp .../largolang/largo.vim ~/.vim/syntax    # Replace ... with that dir

Then add to your .vimrc:

au BufRead,BufNewFile *.largo set filetype=largo

Status

Pre-alpha. Usable as far as it goes, but with gaps — some things simply haven't been needed yet. Not ready for production use, but a good time to get involved if you want to help shape a new language.