Examples

Use Cases

Access Control

can_edit = is_owner | (is_admin & ~is_suspended)
can_delete = is_owner | is_superadmin
can_view = is_public | can_edit

Form Validation

valid_email = matches_regex(r".+@.+\..+")
valid_password = min_length(8) & has_digit & has_uppercase
valid_form = valid_email & valid_password & accepted_terms

Data Pipeline with Fallbacks

# Using Python API
fetch_data = (
    (try_primary_db | try_replica_db | try_cache)
    & validate_schema
    & transform_response
)

# With explicit retry
from kompoz import Retry

resilient_fetch = Retry(
    try_primary_db | try_replica_db,
    max_attempts=3,
    backoff=1.0,
    exponential=True
)

# Using DSL with :retry modifier
reg.load("(try_primary | try_replica):retry(3, 1.0, true) & validate")

Feature Flags

show_feature = (
    is_beta_user
    | (is_premium & feature_enabled("new_dashboard"))
    | percentage_rollout(10)
)

Testing

Kompoz combinators are easy to test:

import pytest
from kompoz import rule

@rule
def is_positive(x: int) -> bool:
    return x > 0

@rule
def is_even(x: int) -> bool:
    return x % 2 == 0

class TestRules:
    def test_simple_rule(self):
        ok, _ = is_positive.run(5)
        assert ok is True

    def test_combined_rule(self):
        combined = is_positive & is_even
        assert combined.run(4)[0] is True
        assert combined.run(3)[0] is False  # odd
        assert combined.run(-2)[0] is False  # negative

    @pytest.mark.parametrize("value,expected", [
        (4, True),
        (3, False),
        (-2, False),
        (0, False),
    ])
    def test_parametrized(self, value, expected):
        combined = is_positive & is_even
        assert combined.run(value)[0] is expected

Example Files

The examples/ directory contains runnable examples:

File	Description
rules_example.py	Using @rule and @rule_args decorators
transforms_example.py	Using @pipe and @pipe_args for data pipelines
registry_example.py	Loading rules from .kpz files
tracing_example.py	Tracing, debugging, and explaining rules
validation_example.py	Validation with error messages
async_example.py	Async rules, transforms, and retry
temporal_example.py	Time-based and date-based rules
functional_example.py	Functional programming patterns and composition
then_operator_example.py	Using >> (THEN) for sequencing
access_control.kpz	Access control with AND/OR/NOT
trading.kpz	Tiered trading permissions
pipeline.kpz	Data pipeline with >> (THEN) operator
pricing.kpz	IF/THEN/ELSE conditional branching
tiered_pricing.kpz	Nested IF/THEN/ELSE for multi-tier logic
content_moderation.kpz	Word-syntax keywords (AND, OR, NOT)
data_enrichment.kpz	:retry and :cached modifiers
fraud_detection.kpz	Complex nested logic with modifiers
feature_flags.kpz	Ternary ? : syntax with :cached

Run any example:

cd kompoz
python examples/rules_example.py
python examples/validation_example.py
python examples/async_example.py
python examples/temporal_example.py