themes

Rosettes themes package.

Semantic token system for syntax highlighting with modern CSS support. Provides palettes, CSS generation, and accessibility validation.

Design Philosophy:

Rosettes uses a semantic role system instead of individual token colors:

1. Roles over Tokens: ~20 semantic roles (FUNCTION, STRING, COMMENT) instead of 100+ token types. Themes define colors for roles.

2. Separation of Concerns: Token → Role mapping is language-agnostic. Palettes define colors for roles, not specific syntax.

3. CSS Custom Properties: Palettes generate CSS variables for runtime theming without regenerating HTML.

Quick Start:

>>> from rosettes.themes import MONOKAI, get_palette
>>> palette = get_palette("monokai")
>>> css_vars = palette.to_css_vars()

Architecture:

• SyntaxRole: Semantic meaning of code elements (FUNCTION, STRING, etc.)
• TokenType → Role: Mapping from fine-grained tokens to semantic roles
• SyntaxPalette: Immutable color definitions for each role
• AdaptivePalette: Light/dark mode support with CSS media queries

Types:

• SyntaxRole: Enum of semantic roles
• SyntaxPalette: Immutable theme definition (~20 color slots)
• AdaptivePalette: Light/dark adaptive theme

Built-in Palettes:

Bengal Themes:

• BENGAL_TIGER: Warm orange tones (default)
• BENGAL_SNOW_LYNX: Cool light theme
• BENGAL_CHARCOAL: Dark gray theme
• BENGAL_BLUE: Cool blue tones

Third-Party Compatible:

• MONOKAI: Classic dark theme
• DRACULA: Purple-accented dark theme
• GITHUB: Light/dark GitHub-style themes

Custom Palettes:

>>> from rosettes.themes import SyntaxPalette, register_palette
>>> my_theme = SyntaxPalette(
...     name="my-theme",
...     background="#1a1a1a",
...     text="#f0f0f0",
...     string="#98c379",
...     function="#61afef",
... )
>>> register_palette(my_theme)

See Also:

• rosettes.themes._roles: SyntaxRole enum definition
• rosettes.themes._mapping: TokenType → SyntaxRole mapping
• rosettes.themes._palette: SyntaxPalette and AdaptivePalette classes