themes._mapping

Token type to semantic role mapping.

Maps Pygments-compatible TokenType values to semantic SyntaxRole values. This provides the abstraction layer between tokens and colors.

Design Philosophy:

This module is the bridge between fine-grained token types and semantic color roles:

TokenType (100+ types) → SyntaxRole (20 roles) → Color

Why this indirection?

1. Theme Simplicity: Authors define ~20 colors, not 100+
2. Consistency: Related tokens get the same color
3. Flexibility: Can adjust mapping without changing themes

Mapping Strategy:

Keywords → Control/Declaration based on purpose:

• if/for/while→ CONTROL_FLOW (affects execution)
• def/class→ DECLARATION (defines structure)
• import/from→ IMPORT (brings in dependencies)

Names → Identity based on what they represent:

• function names → FUNCTION
• class names → TYPE
• variables → VARIABLE

Literals → Data based on value type:

• strings → STRING
• numbers → NUMBER
• True/False/None→ BOOLEAN

Pygments Compatibility:

PYGMENTS_CLASS_MAPmaps roles to Pygments CSS class suffixes. This enables drop-in compatibility with Pygments themes:

SyntaxRole.FUNCTION → "nf" → .nf { color: ... }

Thread-Safety:

All data structures are immutable dicts. Dict lookups are atomic in CPython, so no synchronization is needed.

See Also:

• rosettes._types.TokenType: The fine-grained token types
• rosettes.themes._roles.SyntaxRole: The semantic role enum
• rosettes.themes._palette: How roles get colors