Lupe

A World-Class REPL for UP (Unified Properties)

Experience the future of interactive data exploration. Lupe is a modern REPL environment designed for the UP language—combining powerful features with an intuitive interface for developers, data engineers, and configuration enthusiasts.

example.up
$ lupe Welcome to Lupe REPL v1.0.0 > config { name MyApp version!semver 1.2.3 server { host localhost port!int 8080 } } ✓ Parsed successfully
Learn UP Explore Features

Live Syntax Highlighting

Real-time syntax highlighting with semantic analysis. See types, blocks, and values instantly as you type with customizable themes.

Intelligent Autocomplete

Context-aware suggestions for properties, types, and values. ML-powered completions learn from your patterns and common UP idioms.

Multi-Format Export

Convert UP to JSON, YAML, TOML, XML, or back. Perfect for integrating UP into existing workflows and toolchains.

Core REPL Features

Essential Capabilities

  • Instant Evaluation — Real-time parsing and validation as you type
  • Error Highlighting — Precise error locations with helpful suggestions
  • History Navigation — Full command history with search and replay
  • Multi-line Editing — Seamless multi-line input with smart indentation
  • Persistent Sessions — Save and restore REPL sessions across browser visits
  • Keyboard Shortcuts — Vim and Emacs keybinding modes available
  • Variable Inspection — Explore defined variables and their resolved values
  • Schema Validation — Optional schema checking with custom rules
REPL Session
> vars { api_url https://api.example.com timeout!int 30 } > config { endpoint $vars.api_url timeout $vars.timeout } ✓ Variables resolved: endpoint="https://api.example.com", timeout=30

Advanced Features

Visual Tree Explorer

Navigate complex nested structures with an interactive tree view. Collapse, expand, and search through your data hierarchy.

.tree(config)

Diff Viewer

Compare two UP documents side-by-side with intelligent semantic diffing that understands property equivalence.

.diff(old, new)

Type Inference

Automatic type detection with suggestions. Get hints for proper type annotations based on value patterns.

.infer(value)

Query Language

JSONPath-like queries for UP structures. Filter, transform, and extract data with expressive query syntax.

.query("$.server.port")

Collaboration Mode

Share REPL sessions with team members. Real-time collaborative editing with presence indicators.

.share("session-id")

Plugin System

Extend Lupe with custom validators, formatters, and integrations. Build your own tools on top of the REPL.

.load("plugin-name")

Innovative Features

Lupe pushes the boundaries of what a REPL can be:

AI-Powered Code Generation

Describe your data structure in natural language, and Lupe generates the UP code. "Create a config for a web server with TLS support" → instant UP code with proper types and structure.

Time-Travel Debugging

Rewind your REPL session to any previous state. See how values evolved, replay commands, and understand the path that led to the current state. Complete with visual timeline and state snapshots.

Semantic Search

Search your UP documents by meaning, not just text. Find "database configurations" even if they're structured differently across files. Uses embeddings and semantic matching.

Visual Schema Designer

Design schemas graphically with drag-and-drop. Define constraints, relationships, and validation rules visually, then generate UP schemas automatically.

Pattern Library

Curated collection of UP patterns for common use cases: API configs, database setups, CI/CD pipelines, cloud infrastructure. One-click templates with smart placeholders.

Live Documentation

Hover over any property to see inline documentation from uplang.org. Context-aware help that understands what you're trying to do and suggests best practices.

Stress Testing Simulator

Test your UP configurations with synthetic data generation. Validate against edge cases, generate random valid inputs, and ensure your configs handle unexpected scenarios.

Cross-Language Code Bridge

See how your UP data would look in Python, JavaScript, Rust, or Go. Generate type-safe language bindings and understand the mapping between UP and your target language.

Performance Profiler

Analyze parsing performance, memory usage, and optimization opportunities. Identify slow patterns and get suggestions for more efficient structures.

Git Integration

Version control built into the REPL. Commit changes, view history, and collaborate using familiar Git workflows—all without leaving the browser.

About UP (Unified Properties)

UP is a modern data serialization format that's simpler than YAML, more powerful than JSON, and more readable than TOML. It features type annotations, clean nesting, multiline strings, tables, and powerful composition capabilities.

Visit uplang.org View Spec on GitHub