noxdafox / psyche

It's cooking

Example

import datetime

from psyche import Fact

class Employee(Fact):
    id: int
    name: str
    surname: str
    email: str
    active: bool

class Role(Fact):
    employee_id: int
    name: str
    salary: int
    start_date: datetime.date
    salary_raise_date: datetime.date

rule ChangeEmail:
    condition:
        empl <- Employee(active == True,
                         email.endswith('acme.org'))
    action:
        print(f"Changing employee {empl.name} {empl.surname} email")
        new_email = empl.email.split('@')[0] + '@acme.com'
        empl.modify(email=new_email)

rule RaiseSalary:
    condition:
        empl <- Employee(eid <- id,
                         active == True)
        role <- Role(employee_id == eid,
                     datetime.date.today() - salary_raise_date > THREE_YEARS)
    action:
        print(f"Raising {empl.name} {empl.surname} ({role.name}) salary")
        role.modify(salary=role.salary + 300,
                    salary_raise_date=datetime.date.today())

THREE_YEARS = datetime.timedelta(weeks=54*3)