deep-modules

name	deep-modules
description	Deep vs shallow modules (Ousterhout). Use when designing APIs, reviewing module boundaries, or when the user wants smaller interfaces with richer implementations.

Deep Modules

From "A Philosophy of Software Design":

Deep module = small interface + lots of implementation

┌─────────────────────┐
│   Small Interface   │  ← Few methods, simple params
├─────────────────────┤
│                     │
│                     │
│  Deep Implementation│  ← Complex logic hidden
│                     │
│                     │
└─────────────────────┘

Shallow module = large interface + little implementation (avoid)

┌─────────────────────────────────┐
│       Large Interface           │  ← Many methods, complex params
├─────────────────────────────────┤
│  Thin Implementation            │  ← Just passes through
└─────────────────────────────────┘

When designing interfaces, ask:

• Can I reduce the number of methods?
• Can I simplify the parameters?
• Can I hide more complexity inside?