# PRISM — Program Resolution & Inheritance Structure Map

> PRISM is a VS Code extension that shows, in real time, exactly where a method lives in its inheritance chain and whether the version you're editing is the one that actually runs.

## What PRISM does

PRISM analyzes Python (and 9 other languages) class hierarchies using static analysis. As a developer moves their cursor in VS Code, PRISM computes the method resolution order (MRO) and classifies every method into one of four states:

- **owns**: Only this class defines it. It runs.
- **overrides**: A base class also defines it, but this version wins.
- **overridden**: This version runs for direct instances, but a descendant redefines it.
- **shadowed**: A base class version wins. This code never runs (dead code).

Analysis completes in under 200 milliseconds per cursor movement.

## Install

- VS Code Marketplace: https://marketplace.visualstudio.com/items?itemName=TemilolaOlowolayemo.prism-vscode
- Open VSX (Cursor, VSCodium): https://open-vsx.org/extension/TemilolaOlowolayemo/prism-vscode

## Key features

- Live MRO panel with class cards and method pills
- Four color-coded method statuses (owns, overrides, overridden, shadowed)
- Interactive mindmap and radial hierarchy views
- CodeLens editor annotations
- Workspace-wide dead code scanning
- Hover cards with file, line, status, and super() call info
- 10 language support: Python, TypeScript, Java, C++, Go, C#, Ruby, PHP, Swift, Kotlin

## Technical architecture

- Persistent Python subprocess (no per-request spawning)
- AST caching keyed by file mtime
- C3 linearization computed from source (no runtime execution)
- JSON-over-stdin/stdout IPC between TypeScript extension and Python backend
- 80ms cursor debounce + <120ms analysis = <200ms total

## Links

- Website: https://prism-tools.dev
- Features: https://prism-tools.dev/features
- Playground: https://prism-tools.dev/playground
- Blog: https://prism-tools.dev/blog
- About: https://prism-tools.dev/about
- GitHub: https://github.com/temilola23

## Author

Temilola Olowolayemo — built PRISM after an internship at Uber's ML Platform team, where deep inheritance hierarchies in production ML code made it impossible to know which method version actually ran.