# Long Parameter List

> A defect in which a signature grows so many parameters that a caller can no longer read or validate it.

Record: `architecture:long-parameter-list`
Kind: anti-pattern
Layer: [Enforcement Core](https://banes-lab.com/records/layer/enforcement-core.md)
Severity: discouraged
Scope: modularity, contract_compatibility, correctness_verification, object_creation
Canonical: https://banes-lab.com/ontology#architecture-long-parameter-list

Listed in [Architecture principles](https://banes-lab.com/api/records/architecture.md), after [Boolean Trap](https://banes-lab.com/records/architecture/boolean-trap.md) and before [Magic Value](https://banes-lab.com/records/architecture/magic-value.md).

## Repair

- Refactored by: introduce_parameter_object, builder, [value_object](https://banes-lab.com/records/architecture/value-object.md), dependency_container
- Detected by: arity_above_threshold, repeated_parameter_groups, many_optional_params
- Violated by: Grow function or constructor signatures until related inputs, optional modes, and dependencies become hard to understand or validate.
- Measured by: parameters per signature above the threshold
- Enforced by: a lint rule on parameter count

## Severity

- [discouraged](https://banes-lab.com/records/vocabulary/severity-discouraged.md)

## Category

- [Anti-patterns](https://banes-lab.com/records/architecture-category/anti-patterns.md)

## Force

- [Contract compatibility](https://banes-lab.com/records/force/contract-compatibility.md)
- [Correctness verification](https://banes-lab.com/records/force/correctness-verification.md)
- [Modularity](https://banes-lab.com/records/force/modularity.md)
- [Object creation](https://banes-lab.com/records/force/object-creation.md)

## Negated by

- [Value Object](https://banes-lab.com/records/architecture/value-object.md)

## Linked from

- [Anti-patterns](https://banes-lab.com/ontology/principles/architecture-category-anti-patterns.md)
- [Domain Architecture](https://banes-lab.com/ontology/principles/architecture-category-domain-architecture.md)
- [Severity levels](https://banes-lab.com/ontology/schema/the-vocabulary-severity.md)
- [The forces](https://banes-lab.com/ontology/schema/the-forces.md)