# Sideways Overflow

> A design pattern that resolves a naming collision with the filename's variant slot and resolves breadth with a sibling subject folder.

Record: `architecture:sideways-overflow`
Kind: pattern
Layer: [Structural Core](https://banes-lab.com/records/layer/structural-core.md)
Severity: mandatory
Scope: folder, filename
Canonical: https://banes-lab.com/ontology#architecture-sideways-overflow

Listed in [Architecture principles](https://banes-lab.com/api/records/architecture.md), after [Bounded Nesting Depth](https://banes-lab.com/records/architecture/bounded-nesting-depth.md) and before [One Concern Per File](https://banes-lab.com/records/architecture/one-concern-per-file.md).

## Repair

- Refactored by: Insert a Declared Variant, Split into Sibling Subject Folders
- Detected by: a folder level introduced where a variant or a sibling subject folder resolves the collision
- Violated by: relieving pressure downward, by nesting, instead of sideways
- Measured by: nesting-relief count
- Enforced by: placement gate, reshape review

## Requires

- [Variant Slot](https://banes-lab.com/records/lexicon/variant-slot.md)
- [Subject Folder](https://banes-lab.com/records/lexicon/subject-folder.md)

## Reinforces

- [Bounded Nesting Depth](https://banes-lab.com/records/architecture/bounded-nesting-depth.md)

## Enables

- [Glob Resolvability](https://banes-lab.com/records/lexicon/glob-resolvability.md)

## Conflicts with

- [Downward Nesting](https://banes-lab.com/records/lexicon/downward-nesting.md)

## Severity

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

## Category

- [Taxonomy / Classification / Naming](https://banes-lab.com/records/architecture-category/taxonomy-classification-naming.md)

## Linked from

- [Placement is a grammar](https://banes-lab.com/disciplined-methodology/build/placement-is-a-grammar.md)
- [Taxonomy / Classification / Naming](https://banes-lab.com/ontology/principles/architecture-category-taxonomy-classification-naming.md)
- [Taxonomy / Classification / Naming](https://banes-lab.com/ontology/lexicon/lexicon-category-taxonomy-classification-naming.md)
- [Severity levels](https://banes-lab.com/ontology/schema/the-vocabulary-severity.md)

## Evidence in the code

- [parseFilename](https://banes-lab.com/source/coordination/tools/core/validators/taxonomy.validator.ts.md)