Rust Dependencies for pi-mono Feature Parity

Overview

This document maps the features from pi-mono’s TypeScript implementation to equivalent Rust crates for our TUI application.

Core TUI Framework

pi-mono: pi-tui (custom TypeScript)

Features:

• Differential rendering (only updates changed lines)
• Component-based architecture
• Viewport management with scrollback
• ANSI escape sequence safety
• Overlay system for modals/popups

Rust Equivalent:

ratatui = "0.30"
crossterm = "0.29"  # Backend for ratatui

Notes:

• ✅ ratatui has built-in differential rendering
• ✅ Component system via Widget trait
• ✅ Viewport management included
• ✅ ANSI safety handled by crossterm

Text Editor / Input

pi-mono: Custom editor in pi-tui

Features:

• Multi-line text input
• Cursor movement
• Syntax highlighting integration
• Vim-style or Emacs keybindings
• Text selection

Rust Options:

Option 1: Basic input (built-in)

ratatui = "0.30"  # Has TextArea widget

Option 2: Enhanced editor

# Vim-like editor
edtui = "0.11"
# OR
tui-textarea = "0.4"
# OR
ratatui-code-editor = "0.0.1"  # Tree-sitter powered

Recommendation: Start with ratatui’s built-in TextArea, upgrade to edtui or ratatui-code-editor if we need vim bindings or advanced editing.

Markdown Rendering

pi-mono: marked (TypeScript library)

Features:

• Parse markdown to styled terminal output
• Support for headings, lists, code blocks, links
• Custom rendering for AI responses

Rust Equivalent:

tui-markdown = "0.3"
pulldown-cmark = "0.13"  # Underlying parser

Alternative (more comprehensive):

md-tui = "0.9"  # Full markdown viewer with navigation

Notes:

• tui-markdown converts markdown to ratatui Text values
• Supports all standard markdown features
• Can customize styling for AI output

Syntax Highlighting

pi-mono: Custom integration with highlighting

Features:

• Code block syntax highlighting
• Multiple language support
• Theme support

Rust Equivalent:

syntect = "5.3"        # Core syntax highlighting
syntect-tui = "3.0"    # Bridge to ratatui styles

Alternative (tree-sitter based):

tui-syntax = "0.4"     # Tree-sitter based
tree-sitter = "0.24"   # Parser framework

Notes:

• syntect uses Sublime Text syntax definitions (high quality)
• 100+ languages supported out of the box
• syntect-tui converts syntect styles to ratatui Styles

File Tree / Navigation

pi-mono: Tree selector for sessions and files

Features:

• Hierarchical tree view
• Collapsible/expandable nodes
• Keyboard navigation
• File icons/indicators

Rust Equivalent:

tui-tree-widget = "0.24"
# OR
ratatui-explorer = "0.2"

Notes:

• tui-tree-widget: Pure tree widget for any tree data
• ratatui-explorer: File explorer specifically (like ranger)

Diff Viewing

pi-mono: File diff display for code changes

Features:

• Side-by-side or unified diff
• Syntax highlighting in diffs
• Color-coded additions/deletions
• Line numbers

Rust Equivalent:

# Option 1: Use syntect with custom diff logic
syntect = "5.3"

# Option 2: Leverage delta (pager)
# Shell out to delta or integrate as library

Implementation approach:

#![allow(unused)]
fn main() {
// Parse diff output
// Use syntect to highlight each line
// Apply ratatui styles for additions (green) / deletions (red)
}

Clipboard Integration

pi-mono: Clipboard access for copy/paste

Features:

• Copy text to system clipboard
• Paste from clipboard
• Cross-platform support

Rust Equivalent:

arboard = "3.6"

Notes:

• Cross-platform (Linux X11/Wayland, macOS, Windows)
• Supports both text and images
• 1Password maintains this crate (high quality)

Async / Streaming

pi-mono: Event-driven with async/await

Features:

• Handle multiple async events
• Stream LLM responses
• Non-blocking UI updates
• Event queue/channels

Rust Equivalent:

tokio = { version = "1", features = ["full"] }
tokio-stream = "0.1"
futures = "0.3"
async-trait = "0.1"

Pattern:

#![allow(unused)]
fn main() {
// Event loop with tokio
let (tx, mut rx) = tokio::sync::mpsc::unbounded_channel();

// Spawn async task for events
tokio::spawn(async move {
    while let Some(event) = rx.recv().await {
        // Handle event
    }
});
}

Configuration Management

pi-mono: YAML/JSON config files

Features:

• User config in ~/.config/pi/
• Project-level config
• Environment variable overrides
• Theme configuration

Rust Equivalent:

config = "0.15"        # Layered config (file, env, etc.)
toml = "0.9"           # TOML parsing
serde = { version = "1.0", features = ["derive"] }
directories = "5"      # XDG dirs (cross-platform)

Alternative (more powerful):

figment = "0.10"       # Used by Rocket, very flexible

Notes:

• config crate: Supports TOML, YAML, JSON, INI
• directories: Gets platform-appropriate config dirs
• XDG on Linux, ~/Library/Application Support on macOS, %APPDATA% on Windows

HTTP / LLM API

pi-mono: pi-ai (unified LLM API)

Features:

• Multiple provider support (OpenAI, Anthropic, etc.)
• Streaming responses
• Retry logic
• Authentication

Rust Equivalent:

reqwest = { version = "0.12", features = ["json", "stream"] }
tokio = "1"
serde = { version = "1.0", features = ["derive"] }
serde_json = "1.0"

For specific providers:

async-openai = "0.26"  # If using OpenAI specifically

Custom trait approach (recommended):

#![allow(unused)]
fn main() {
#[async_trait]
trait LlmProvider {
    async fn complete(&self, request: Request) -> Result<Response>;
    async fn stream(&self, request: Request) -> Result<Stream<Item=Token>>;
}
}

Themes

pi-mono: Theme system with JSON themes

Features:

• Custom color schemes
• User-defined themes
• Syntax highlighting themes
• Terminal color detection

Rust Equivalent:

ratatui = "0.30"  # Has Style system
syntect = "5.3"   # Has theme support for syntax

For theme loading:

serde = { version = "1.0", features = ["derive"] }
toml = "0.9"      # Or json, yaml

Implementation:

#![allow(unused)]
fn main() {
#[derive(Deserialize)]
struct Theme {
    background: Color,
    foreground: Color,
    accent: Color,
    // ...
}
}

Key Bindings / Input

pi-mono: Custom keyboard protocol

Features:

• Vim-style keybindings
• Command palette (/ commands)
• Configurable shortcuts
• Key sequences (chords)

Rust Equivalent:

crossterm = "0.29"  # Has key event handling

For complex keybindings:

#![allow(unused)]
fn main() {
// crossterm provides KeyEvent, KeyCode, KeyModifiers
// Build a keymap system on top

enum Action {
    SendMessage,
    NewConversation,
    Quit,
    // ...
}

struct KeyMap {
    bindings: HashMap<(KeyCode, KeyModifiers), Action>,
}
}

State Management

pi-mono: Agent state management

Features:

• Conversation history
• Context management
• Tool state
• Session persistence

Rust Equivalent:

# In-memory: Standard Rust
# Persistence:
serde = { version = "1.0", features = ["derive"] }
serde_json = "1.0"

# Database (optional):
sqlx = { version = "0.8", features = ["runtime-tokio", "sqlite"] }
# OR for simpler use:
redb = "2.0"  # Pure Rust embedded DB

Complete Cargo.toml

[package]
name = "harness-tui"
version = "0.1.0"
edition = "2021"

[dependencies]
# Core TUI
ratatui = { version = "0.30", features = ["crossterm"] }
crossterm = "0.29"

# Editor
edtui = "0.11"  # Optional: for vim bindings

# Markdown
tui-markdown = "0.3"
pulldown-cmark = "0.13"

# Syntax highlighting
syntect = "5.3"
syntect-tui = "3.0"

# File tree
tui-tree-widget = "0.24"

# Clipboard
arboard = "3.6"

# Async
tokio = { version = "1", features = ["full"] }
tokio-stream = "0.1"
futures = "0.3"
async-trait = "0.1"

# HTTP
reqwest = { version = "0.12", features = ["json", "stream", "rustls-tls"] }

# Config
config = "0.15"
toml = "0.9"
serde = { version = "1.0", features = ["derive"] }
serde_json = "1.0"
directories = "5"

# Persistence (optional)
redb = "2.0"

# Error handling
color-eyre = "0.6"  # Better error reporting
thiserror = "1.0"

# Logging
tracing = "0.1"
tracing-subscriber = { version = "0.3", features = ["env-filter"] }

# CLI
clap = { version = "4.5", features = ["derive"] }

# Utilities
unicode-width = "0.2"
textwrap = "0.16"
chrono = { version = "0.4", features = ["serde"] }

[dev-dependencies]
tokio-test = "0.4"

Feature Comparison Summary

Advantages of Rust Stack

1. Type Safety: Compile-time guarantees for all UI state
2. Performance: Zero-cost abstractions, no GC pauses
3. Single Binary: No Node.js runtime dependency
4. Memory Safety: No null pointer exceptions or undefined behavior
5. Ecosystem: Cross-platform native performance

Development Workflow

# Add dependencies
cargo add ratatui crossterm tokio serde reqwest

# Development
cargo run          # Run TUI
cargo test         # Run tests
cargo clippy       # Lint
cargo build --release  # Optimized build

# Single binary output: target/release/harness-tui

No npm install. No node_modules. No webpack.

Just Rust.