I built a programming language where you can't lose a cent: a 5-minute tour of Quill
Quill is an open-source language for backends, business software and automation. It's built around three ideas: intent is clear, failures are explicit, and correctness is part of the code. Here's a five-
minute tour.
Install
curl --proto '=https' --tlsv1.2 -LsSf github.com/Ngwangshalom/Quill/releases/latest/dow… | sh
## Start a whole app
quill new shop app
cd shop
quill run server.quill
That's a small events company: bookings checked against a type, prices with VAT, three payments that add up to the cent, and an AI assistant. `quill test` runs its tests.
## Data that reads like a sentence
say count of students where score >= 50
say average score of students
say get name of students sorted by highest score
## Money that never loses a cent
say split 100 USD into 3 -- 33.34 USD, 33.33 USD, 33.33 USD
`100 USD + 20 EUR` doesn't run. Quill says it won't mix currencies, and suggests `convert 20 EUR to USD at 0.92`, at the rate you were given.
## Failures you can't forget
fn charge(amount: USD) -> text
fails Declined
...
receipt = charge(5000 USD)
on Declined -> "declined"
Leave out `on Declined` and Quill won't run the program. It tells you which failure you forgot.
## Errors that teach
say total + "hello"
^^^^^^^^^^^^^^^
You're adding money in USD (total) and Text ("hello").
Add or subtract two amounts in the same currency, like 100 USD + 50 USD.
## Join in
Quill is early and open source (Apache 2.0). If you like languages, compilers, docs, or editor tooling, there's plenty to do:
- {% embed Repo: https://github.com/Ngwangshalom/Quill %}
- {% embed Book: https://ngwangshalom.github.io/Quill/ %}
- Learn it with exercises: `quill new practice learn`
Mentions
I built a programming language where you can't lose a cent: a 5-minute tour of Quill Quill is an open-source language for backends, business software and automation. It's built around three ideas: intent is clear, failures are explicit, and correctness is part of the code. Here's a five- minute tour. Install curl --proto '=https' --tlsv1.2 -LsSf github.com/Ngwangshalom/Quill/releases/latest/dow… | sh ## Start a whole app quill new shop app cd shop quill run server.quill That's a small events company: bookings checked against a type, prices with VAT, three payments that add up to the cent, and an AI assistant. `quill test` runs its tests. ## Data that reads like a sentence say count of students where score >= 50 say average score of students say get name of students sorted by highest score ## Money that never loses a cent say split 100 USD into 3 -- 33.34 USD, 33.33 USD, 33.33 USD `100 USD + 20 EUR` doesn't run. Quill says it won't mix currencies, and suggests `convert 20 EUR to USD at 0.92`, at the rate you were given. ## Failures you can't forget fn charge(amount: USD) -> text fails Declined ... receipt = charge(5000 USD) on Declined -> "declined" Leave out `on Declined` and Quill won't run the program. It tells you which failure you forgot. ## Errors that teach say total + "hello" ^^^^^^^^^^^^^^^ You're adding money in USD (total) and Text ("hello"). Add or subtract two amounts in the same currency, like 100 USD + 50 USD. ## Join in Quill is early and open source (Apache 2.0). If you like languages, compilers, docs, or editor tooling, there's plenty to do: - {% embed Repo: https://github.com/Ngwangshalom/Quill %} - {% embed Book: https://ngwangshalom.github.io/Quill/ %} - Learn it with exercises: `quill new practice learn`
Quill – a readable language where money is exact and failures can't hide