# Patterns/composite

> Composite Pattern pattern for C development

- Skill: `majiayu000/patterns-composite` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds add majiayu000/patterns-composite`
- Raw SKILL.md: https://api.skillmd.com/api/skills/majiayu000/patterns-composite/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: majiayu000 (https://skillmd.com/u/majiayu000)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/majiayu000/patterns-composite

---


# Composite Pattern

Compose objects into tree structures. Individual objects and compositions treated uniformly through common interface.

## ikigai Application

**Layer system:** Layers (scrollback, separator, input, spinner) compose into layer stack. Each implements same render interface:
```c
typedef struct {
    void (*render)(void *layer, ik_render_ctx_t *render);
    void (*resize)(void *layer, int width, int height);
} ik_layer_vtable_t;
```

**Rendering:** REPL iterates layers, calls render on each. Doesn't care if layer is simple or composite.

**Future uses:**
- Nested UI components
- Tool result trees
- Message threading/nesting

**Benefit:** Add new layer types without changing render loop.