Feature Request: Built-in Syntax Highlighting for Unknown Languages

[arlotalkington]

Feature Request: Built-in Syntax Highlighting for Unknown Languages

Summary:
VS Code should include a fallback syntax highlighter that automatically provides basic syntax highlighting for files with unknown or custom extensions, without requiring a full TextMate grammar or extension.

Motivation:

• Many developers create or experiment with custom languages (like Hexon) or new file formats.
• Currently, VS Code treats unknown file types as plain text with no syntax highlighting, which hurts readability and development flow.
• Having a generic, heuristic-based fallback highlighter would provide immediate visual structure—highlighting common tokens like keywords, strings, comments, numbers, and punctuation.
• This would reduce the barrier to experimenting with new languages and improve the user experience for niche/custom file types.

Possible Implementation Ideas:

• A default “generic” grammar with common programming constructs.
• Optional AI or pattern-based heuristic highlighting for unknown file extensions.
• A user toggle to enable/disable this fallback highlighting globally.

Benefits:

• Immediate, helpful syntax highlighting for any file, known or unknown.
• Encourages innovation and experimentation with new languages.
• Improves accessibility and readability for custom scripts/configs.