pell 0.1.0

A statically-typed language that compiles to Oracle PL/SQL 19c / 23ai

pell

A statically-typed language that compiles to Oracle PL/SQL 19c / 23ai. Modern syntax, real type checking, ergonomic SQL — and the emitted PL/SQL is a deployable, human-readable, SHA-anchored artifact you commit, audit, and git blame like any other code.

Install

# Core compiler (zero deps)
pip install pell

# + Oracle driver + REPL (for `pell exec`, `pell repl`, `pell sql`, `pell deploy`)
pip install "pell[repl]"

After install, pell is on your PATH:

pell --help
pell build src/hello.pell
pell repl

One look at the lowering

// src/hr/employees.pell
module hr.employees;

pub record Employee { id: number, name: text, level: number }
pub error NotFound { id: number }

pub fn promote(id: number) -> Result<Employee, NotFound> {
    let row: Employee = sql! {
        select id, name, level from employees where id = :id
    }.one()?;
    return Ok(Employee {
        id:    row.id,
        name:  row.name,
        level: row.level + 1,
    });
}

…lowers to PL/SQL you'd write by hand:

CREATE OR REPLACE PACKAGE hr.employees AS
  TYPE t_employee IS RECORD (
    id    NUMBER,
    name  VARCHAR2(4000),
    level NUMBER
  );
  FUNCTION promote(p_id IN NUMBER) RETURN t_employee;
END employees;
/

CREATE OR REPLACE PACKAGE BODY hr.employees AS
  FUNCTION promote(p_id IN NUMBER) RETURN t_employee IS
    l_row t_employee;
    l_ret t_employee;
  BEGIN
    SELECT id, name, level
      INTO l_row
      FROM employees
     WHERE id = p_id;
    l_ret.id    := l_row.id;
    l_ret.name  := l_row.name;
    l_ret.level := (l_row.level + 1);
    RETURN l_ret;
  EXCEPTION
    WHEN NO_DATA_FOUND THEN
      RAISE pell_runtime.hr_employees_notfound;
  END promote;
END employees;
/

Features

• Generics & sum types — Result<T, E>, Option<T>, list<T>
• Real string interpolation — "got {count} tables" with auto-stringify for any type
• Embedded SQL — sql! { ... } with .one() / .collect() / .first() terminators driving the right SELECT INTO shape
• JSON / regex / jq-style queries — first-class, using Oracle 23ai JSON_OBJECT_T natively
• Notebook-style REPL — variable persistence across cells, \load files, catalog:: data dictionary helpers
• Deployment artifact — .sql output is SHA-anchored, byte-stable with --reproducible, meant to be committed

Learn more

• Docs & tutorial: https://batterts.github.io/pell
• JetBrains IDE plugin: https://plugins.jetbrains.com/plugin/31994-pell
• Examples (30+ .pell files + their compiled output): https://github.com/batterts/pell/tree/main/compiler/examples
• Source: https://github.com/batterts/pell
• Issues: https://github.com/batterts/pell/issues

License

MIT — see LICENSE.