PRISM
Program Resolution & Inheritance Shadow Monitor
A VS Code / Cursor extension that shows, in real time as you move your cursor, exactly where a method lives in its inheritance chain and whether the version you are editing is the one that actually runs.
The Problem
You're working on a large Python codebase. You edit DeepSpeedEstimator.setup_dataloader(). You add logging. You test. Nothing happens. Why?
Because DLEstimatorBase.setup_dataloader() is what actually gets called — your version is dead code that never executes. You just wasted 30 minutes.
Inheritance chains in large codebases get deep. Methods get overridden, shadowed, and buried across dozens of files. You grep, you trace, you read docs — and you're still guessing. PRISM eliminates the guesswork. Move your cursor, and within 200ms you know exactly what runs and what doesn't.
Who Is This For
- Developers ramping up on a new codebase — get a full picture of any class hierarchy without digging through layers of inheritance by hand
- Teams maintaining large frameworks — instantly see which methods are dead code across your entire project
- Open-source contributors — understand unfamiliar inheritance structures in seconds, not hours
- Enterprise teams — onboard faster, ship with confidence that you're editing the code that actually runs
Features
Live MRO Panel
Move your cursor into any Python class and PRISM instantly shows the full Method Resolution Order — a vertical stack of class cards with color-coded method pills. Every cursor move triggers a fresh analysis. No manual refresh needed.
Four Method States
| State |
Color |
What It Means |
| Owns |
Green |
This class defines the method. No parent defines it. It runs. |
| Overrides |
Amber |
This class redefines a parent's method. This version wins. |
| Overridden |
Amber |
This version runs here, but a child class has its own version. |
| Shadowed |
Red |
Dead code. A parent class's version runs instead of this one. |
Three Analysis Tabs
Resolution Tab — The main view. Summary bar tells you in one sentence what's happening. MRO chain shows every class in resolution order with clickable navigation. Method pills are color-coded by status. Timeline lanes show the full method landscape at a glance.
Scan Tab — Workspace-wide dead code analysis. Scans every class in your project and surfaces shadowed methods, overridden methods, and descendant relationships. Find dead code you didn't know existed.
Graph Tab — Interactive SVG mindmap of the class hierarchy. Pan, zoom, fit-to-view, focus on cursor class, and toggle dynamic camera follow. See the full inheritance tree rendered as a navigable graph.
Editor Integration
- CodeLens — Inline badges appear directly in your editor:
overridden downstream warns that a child class replaces this method, shadowed by base flags dead code. Click any badge for a quick-pick menu that jumps you straight to the relevant class.
- Hover Cards — Hover over any class or method name for a rich detail popup showing its status, where it's defined, and what overrides or shadows it.
- Inline Decorations — Shadowed methods are visually dimmed. Overridden methods get an amber underline. You can spot dead code without even opening the panel.
- Diagnostics — Dead-code warnings appear in the Problems panel, integrated with your existing workflow.
- Jump to Definition — Click any class name in the MRO chain and your editor jumps to that file and line. Navigate a 10-level inheritance chain in seconds.
Workspace-Wide Dead Code Scan
Run PRISM: Scan Workspace for Dead Code from the command palette to scan your entire project. PRISM indexes every class, computes every MRO, and reports every shadowed method — the ones that exist in your codebase but never actually run.
- Sub-200ms updates from cursor move to visible change
- AST caching per file — only reparses when the file actually changes on disk
- Persistent backend — a long-lived Python subprocess stays warm between requests. Zero cold starts.
- Workspace pre-indexing — on activation, PRISM indexes your entire workspace in the background so class resolution is instant from the first cursor move
- File watcher — when you save, create, or delete files, the index updates automatically
Tested On
PRISM has been tested on real-world, large-scale Python repositories:
| Repository |
Classes Indexed |
Notes |
| PyTorch Lightning |
1,200+ classes |
Deep trainer inheritance chains, complex MRO. Indexes the full workspace in seconds. |
PRISM handles the kind of inheritance depth you find in production frameworks — not just toy examples. If your codebase has classes inheriting from classes inheriting from classes, this is built for you.
Requirements
- VS Code 1.85+ or Cursor
- Python 3.10+ installed and available as
python3 on your PATH
No configuration needed. No API keys. No setup wizards. Install and go.
Getting Started
- Install PRISM from the marketplace
- Open any Python project with class inheritance
- The PRISM sidebar appears automatically in the Activity Bar
- Move your cursor into a class — the panel updates in real time
- Use PRISM: Show Panel (
Cmd+Shift+P) to open the floating panel for more space
Commands
| Command |
Description |
PRISM: Show Panel |
Open the floating PRISM panel for a wider view |
PRISM: Scan Workspace for Dead Code |
Scan every class in your workspace for shadowed methods |
PRISM: Focus Sidebar |
Bring focus to the PRISM sidebar |
Status Bar
PRISM — cursor is inside a class, analysis activePRISM: outside class — cursor is not inside a class definitionPRISM: error — backend issue (check Output panel)
What's Next
Multi-language support is on the way. Stay tuned.
Enjoying PRISM? Leave a rating — it helps other developers discover PRISM and keeps development going.
Found a bug or have a feature request? Reach out — we're listening.
License
All rights reserved. This software may not be copied, modified, or redistributed without explicit permission.
