#Class diagrams (Mermaid fence)

#What it is

The same diagram as Class diagrams; only how you write it differs. This page uses a ```mermaid fence and writes Mermaid source directly.

#When to use it

• The source goes to GitHub and you want the diagram to render there — Pamphlet's own syntax shows up as plain text on GitHub
• You already know Mermaid and would rather not learn a second thing
• You need something the own syntax cannot express (the Traps section below says what)

Otherwise use the own syntax: the field names are fixed, and a mistake is reported on the line it is on.

#How to write it

```mermaid
classDiagram
  class Theme {
    +string name
    +ThemeTokens light
    +ThemeTokens dark
  }
  class ThemeTokens {
    +string bg
    +string fg
  }
  Theme --> ThemeTokens
```

#What comes out

Drawn to SVG at compile time and inlined into the output, so the reader downloads no drawing library and makes no network request. Colours follow the theme; scroll to zoom, drag to pan, double-click to reset.

#Traps

• + public, - private
• --> association, <|-- inheritance, *-- composition
• Past seven or eight classes nobody can follow it