# Ruchy System Operations and I/O Specification

**Version**: 1.0.0  
**Date**: 2025-08-21  
**Status**: Draft  
**Priority**: CRITICAL - Required for Ubuntu Config Scripts migration

## Executive Summary

This specification defines the complete set of system operations, I/O capabilities, and runtime features required for Ruchy to fully replace Deno TypeScript in production system configuration and automation tasks. Based on reverse-engineering 95 TypeScript files from ubuntu-config-scripts, this document outlines exactly what Ruchy needs to achieve feature parity.

## 1. Core Runtime Requirements

### 1.1 Command Line Interface

**Current Status**: ✅ Partially Implemented  
**Gap**: Missing subcommands and options

```ruchy
// Required CLI commands (like Deno)
ruchy run <script.ruchy> [args...]        // ✅ Implemented
ruchy check <script.ruchy>                // ✅ Implemented  
ruchy test [pattern]                      // ✅ Implemented (needs work)
ruchy fmt [files...]                      // ✅ Implemented (outputs AST)
ruchy lint [files...]                     // ✅ Implemented
ruchy compile <script> -o <binary>        // ❌ Not Implemented
ruchy repl                                // ✅ Implemented
ruchy doc <files...>                      // ✅ Implemented
ruchy bench <files...>                    // ✅ Implemented
ruchy upgrade                             // ❌ Not Implemented
ruchy install <package>                   // ❌ Not Implemented
```

### 1.2 Runtime Permissions Model

**Current Status**: ❌ Not Implemented  
**Required**: Fine-grained permission system

```ruchy
// Permission flags (like Deno)
ruchy run --allow-read=/path script.ruchy
ruchy run --allow-write=/path script.ruchy
ruchy run --allow-net=domain.com script.ruchy
ruchy run --allow-env=VAR1,VAR2 script.ruchy
ruchy run --allow-run=git,make script.ruchy
ruchy run --allow-all script.ruchy  // Development mode
```

## 2. System Operations API

### 2.1 Process Management

**Current Status**: ❌ Not Implemented  
**Priority**: CRITICAL

```ruchy
// Process spawning and control
mod std::process {
    struct Command {
        fn new(program: String) -> Command
        fn arg(self, arg: String) -> Command
        fn args(self, args: [String]) -> Command
        fn env(self, key: String, value: String) -> Command
        fn current_dir(self, dir: String) -> Command
        fn stdin(self, cfg: Stdio) -> Command
        fn stdout(self, cfg: Stdio) -> Command
        fn stderr(self, cfg: Stdio) -> Command
        fn spawn(self) -> Result<Child, Error>
        fn output(self) -> Result<Output, Error>
        fn status(self) -> Result<ExitStatus, Error>
    }
    
    struct Child {
        fn id() -> u32
        fn kill() -> Result<(), Error>
        fn wait() -> Result<ExitStatus, Error>
        fn wait_with_output() -> Result<Output, Error>
        stdin: Option<ChildStdin>
        stdout: Option<ChildStdout>
        stderr: Option<ChildStderr>
    }
    
    struct Output {
        status: ExitStatus
        stdout: Bytes
        stderr: Bytes
    }
    
    enum Stdio {
        Inherit,
        Piped,
        Null,
    }
}

// Example usage
let result = Command::new("apt-get")
    .args(["install", "-y", "curl"])
    .stdout(Stdio::Piped)
    .output()?
```

### 2.2 File System Operations

**Current Status**: ❌ Not Implemented  
**Priority**: CRITICAL

```ruchy
mod std::fs {
    // File reading
    fn read_to_string(path: String) -> Result<String, Error>
    fn read(path: String) -> Result<Bytes, Error>
    
    // File writing
    fn write(path: String, contents: Bytes) -> Result<(), Error>
    fn write_string(path: String, contents: String) -> Result<(), Error>
    fn append(path: String, contents: Bytes) -> Result<(), Error>
    
    // File metadata
    fn metadata(path: String) -> Result<Metadata, Error>
    fn exists(path: String) -> bool
    fn is_file(path: String) -> bool
    fn is_dir(path: String) -> bool
    
    // Directory operations
    fn create_dir(path: String) -> Result<(), Error>
    fn create_dir_all(path: String) -> Result<(), Error>
    fn remove_dir(path: String) -> Result<(), Error>
    fn remove_dir_all(path: String) -> Result<(), Error>
    fn read_dir(path: String) -> Result<DirIterator, Error>
    
    // File operations
    fn copy(from: String, to: String) -> Result<u64, Error>
    fn rename(from: String, to: String) -> Result<(), Error>
    fn remove_file(path: String) -> Result<(), Error>
    
    // Permissions
    fn set_permissions(path: String, perm: Permissions) -> Result<(), Error>
    
    // Temporary files
    fn temp_dir() -> String
    fn create_temp_dir(prefix: String) -> Result<TempDir, Error>
    
    struct Metadata {
        fn len() -> u64
        fn is_file() -> bool
        fn is_dir() -> bool
        fn is_symlink() -> bool
        fn modified() -> Result<SystemTime, Error>
        fn accessed() -> Result<SystemTime, Error>
        fn created() -> Result<SystemTime, Error>
        fn permissions() -> Permissions
    }
    
    struct Permissions {
        fn readonly() -> bool
        fn set_readonly(readonly: bool)
        fn mode() -> u32  // Unix only
        fn set_mode(mode: u32)  // Unix only
    }
}
```

### 2.3 Environment Variables

**Current Status**: ❌ Not Implemented  
**Priority**: HIGH

```ruchy
mod std::env {
    fn var(key: String) -> Result<String, Error>
    fn var_os(key: String) -> Option<OsString>
    fn set_var(key: String, value: String)
    fn remove_var(key: String)
    fn vars() -> Map<String, String>
    fn current_dir() -> Result<PathBuf, Error>
    fn set_current_dir(path: Path) -> Result<(), Error>
    fn home_dir() -> Option<PathBuf>
    fn temp_dir() -> PathBuf
    fn current_exe() -> Result<PathBuf, Error>
    fn args() -> [String]
}
```

### 2.4 User and Permissions

**Current Status**: ❌ Not Implemented  
**Priority**: HIGH

```ruchy
mod std::os::unix {
    fn uid() -> u32
    fn gid() -> u32
    fn effective_uid() -> u32
    fn effective_gid() -> u32
    fn username() -> Option<String>
    fn hostname() -> Result<String, Error>
}
```

## 3. I/O Operations

### 3.1 Standard I/O

**Current Status**: ⚠️ Partially Implemented (println only)  
**Priority**: CRITICAL

```ruchy
mod std::io {
    // Standard streams
    fn stdin() -> Stdin
    fn stdout() -> Stdout
    fn stderr() -> Stderr
    
    struct Stdin {
        fn read_line() -> Result<String, Error>
        fn read_all() -> Result<String, Error>
        fn read_bytes(n: usize) -> Result<Bytes, Error>
        fn is_terminal() -> bool
    }
    
    struct Stdout {
        fn write(data: Bytes) -> Result<usize, Error>
        fn write_all(data: Bytes) -> Result<(), Error>
        fn flush() -> Result<(), Error>
        fn is_terminal() -> bool
    }
    
    struct Stderr {
        fn write(data: Bytes) -> Result<usize, Error>
        fn write_all(data: Bytes) -> Result<(), Error>
        fn flush() -> Result<(), Error>
        fn is_terminal() -> bool
    }
    
    // Print functions (currently only println exists)
    fn print(msg: String)           // ❌ Not Implemented
    fn println(msg: String)          // ✅ Implemented
    fn eprint(msg: String)           // ❌ Not Implemented
    fn eprintln(msg: String)         // ❌ Not Implemented
    
    // Formatted printing
    fn format(fmt: String, args: ...) -> String  // ❌ Not Implemented
}
```

### 3.2 File I/O

**Current Status**: ❌ Not Implemented  
**Priority**: CRITICAL

```ruchy
mod std::fs {
    struct File {
        fn open(path: String) -> Result<File, Error>
        fn create(path: String) -> Result<File, Error>
        fn read(&mut self, buf: &mut [u8]) -> Result<usize, Error>
        fn write(&mut self, buf: &[u8]) -> Result<usize, Error>
        fn seek(&mut self, pos: SeekFrom) -> Result<u64, Error>
        fn sync_all(&self) -> Result<(), Error>
        fn sync_data(&self) -> Result<(), Error>
        fn set_len(&self, size: u64) -> Result<(), Error>
        fn metadata(&self) -> Result<Metadata, Error>
    }
    
    enum SeekFrom {
        Start(u64),
        End(i64),
        Current(i64),
    }
}
```

### 3.3 Network I/O

**Current Status**: ❌ Not Implemented  
**Priority**: MEDIUM (needed for package management)

```ruchy
mod std::net {
    // HTTP Client
    fn fetch(url: String, options: FetchOptions) -> Result<Response, Error>
    
    struct FetchOptions {
        method: String,
        headers: Map<String, String>,
        body: Option<Bytes>,
        timeout: Option<Duration>,
    }
    
    struct Response {
        status: u16,
        headers: Map<String, String>,
        fn text() -> Result<String, Error>
        fn json<T>() -> Result<T, Error>
        fn bytes() -> Result<Bytes, Error>
    }
    
    // TCP
    struct TcpListener {
        fn bind(addr: String) -> Result<TcpListener, Error>
        fn accept() -> Result<(TcpStream, SocketAddr), Error>
    }
    
    struct TcpStream {
        fn connect(addr: String) -> Result<TcpStream, Error>
        fn read(&mut self, buf: &mut [u8]) -> Result<usize, Error>
        fn write(&mut self, buf: &[u8]) -> Result<usize, Error>
    }
}
```

## 4. Path Operations

**Current Status**: ❌ Not Implemented  
**Priority**: HIGH

```ruchy
mod std::path {
    struct Path {
        fn new(s: String) -> Path
        fn parent() -> Option<Path>
        fn file_name() -> Option<String>
        fn file_stem() -> Option<String>
        fn extension() -> Option<String>
        fn join(path: Path) -> Path
        fn with_file_name(name: String) -> Path
        fn with_extension(ext: String) -> Path
        fn exists() -> bool
        fn is_absolute() -> bool
        fn is_relative() -> bool
        fn to_str() -> Option<String>
        fn canonicalize() -> Result<PathBuf, Error>
    }
    
    fn join(parts: [String]) -> PathBuf
    fn dirname(path: String) -> String
    fn basename(path: String) -> String
    fn resolve(path: String) -> String
    fn relative(from: String, to: String) -> String
    fn is_absolute(path: String) -> bool
}
```

## 5. Time and Date

**Current Status**: ❌ Not Implemented  
**Priority**: MEDIUM

```ruchy
mod std::time {
    struct SystemTime {
        fn now() -> SystemTime
        fn duration_since(earlier: SystemTime) -> Result<Duration, Error>
        fn elapsed() -> Result<Duration, Error>
    }
    
    struct Duration {
        fn from_secs(secs: u64) -> Duration
        fn from_millis(millis: u64) -> Duration
        fn from_micros(micros: u64) -> Duration
        fn from_nanos(nanos: u64) -> Duration
        fn as_secs() -> u64
        fn as_millis() -> u128
        fn as_micros() -> u128
        fn as_nanos() -> u128
    }
    
    struct Instant {
        fn now() -> Instant
        fn duration_since(earlier: Instant) -> Duration
        fn elapsed() -> Duration
    }
    
    // Date/time formatting
    fn format_rfc3339(time: SystemTime) -> String
    fn parse_rfc3339(s: String) -> Result<SystemTime, Error>
}
```

## 6. JSON and Serialization

**Current Status**: ❌ Not Implemented  
**Priority**: HIGH

```ruchy
mod std::json {
    fn parse(s: String) -> Result<JsonValue, Error>
    fn stringify(value: JsonValue) -> String
    fn stringify_pretty(value: JsonValue, indent: usize) -> String
    
    // Derive macros
    #[derive(Serialize, Deserialize)]
    struct Config {
        name: String,
        value: i32,
    }
    
    // Manual serialization
    fn to_json<T: Serialize>(value: T) -> Result<String, Error>
    fn from_json<T: Deserialize>(s: String) -> Result<T, Error>
}
```

## 7. Testing Framework

**Current Status**: ⚠️ Basic Implementation  
**Priority**: HIGH

```ruchy
mod std::test {
    // Test macros
    #[test]
    fn test_addition() {
        assert_eq!(2 + 2, 4)
    }
    
    #[test]
    #[should_panic]
    fn test_panic() {
        panic!("expected panic")
    }
    
    #[test]
    #[ignore]
    fn expensive_test() {
        // Skipped unless --ignored flag
    }
    
    // Assertions
    fn assert!(condition: bool, msg: String)
    fn assert_eq!(left: T, right: T, msg: String)
    fn assert_ne!(left: T, right: T, msg: String)
    fn assert_gt!(left: T, right: T, msg: String)
    fn assert_lt!(left: T, right: T, msg: String)
    fn assert_contains!(haystack: String, needle: String)
    fn assert_throws!(expr: () -> T, error_type: Type)
    
    // Property-based testing
    mod property {
        fn check<T>(name: String, gen: Generator<T>, prop: fn(T) -> bool)
        fn check_async<T>(name: String, gen: Generator<T>, prop: async fn(T) -> bool)
        
        // Generators
        fn arbitrary<T>() -> Generator<T>
        fn integer(min: i64, max: i64) -> Generator<i64>
        fn float(min: f64, max: f64) -> Generator<f64>
        fn string(min_len: usize, max_len: usize) -> Generator<String>
        fn array<T>(gen: Generator<T>, min_len: usize, max_len: usize) -> Generator<[T]>
        fn one_of<T>(values: [T]) -> Generator<T>
    }
    
    // Mocking
    mod mock {
        fn command(name: String) -> MockCommand
        fn file_system() -> MockFileSystem
        
        struct MockCommand {
            fn expect_args(args: [String]) -> MockCommand
            fn returns_output(stdout: String, stderr: String, code: i32) -> MockCommand
        }
    }
}
```

## 8. Logging and Debugging

**Current Status**: ⚠️ Basic println only  
**Priority**: HIGH

```ruchy
mod std::log {
    enum Level {
        Trace,
        Debug,
        Info,
        Warn,
        Error,
    }
    
    fn trace(msg: String)
    fn debug(msg: String)
    fn info(msg: String)
    fn warn(msg: String)
    fn error(msg: String)
    
    struct Logger {
        fn new(name: String) -> Logger
        fn level(level: Level) -> Logger
        fn child(name: String) -> Logger
        fn with_context(key: String, value: Any) -> Logger
        
        fn trace(&self, msg: String)
        fn debug(&self, msg: String)
        fn info(&self, msg: String)
        fn warn(&self, msg: String)
        fn error(&self, msg: String)
    }
    
    // Debug printing
    fn dbg!(value: T) -> T  // Prints and returns value
}
```

## 9. Regular Expressions

**Current Status**: ❌ Not Implemented  
**Priority**: MEDIUM

```ruchy
mod std::regex {
    struct Regex {
        fn new(pattern: String) -> Result<Regex, Error>
        fn is_match(&self, text: String) -> bool
        fn find(&self, text: String) -> Option<Match>
        fn find_all(&self, text: String) -> [Match]
        fn captures(&self, text: String) -> Option<Captures>
        fn replace(&self, text: String, rep: String) -> String
        fn replace_all(&self, text: String, rep: String) -> String
        fn split(&self, text: String) -> [String]
    }
    
    struct Match {
        fn start() -> usize
        fn end() -> usize
        fn as_str() -> String
    }
    
    struct Captures {
        fn get(index: usize) -> Option<Match>
        fn name(name: String) -> Option<Match>
        fn len() -> usize
    }
}
```

## 10. Async/Await Runtime

**Current Status**: ⚠️ Parser support, no runtime  
**Priority**: HIGH

```ruchy
// Async functions
async fn fetch_data(url: String) -> Result<String, Error> {
    let response = await fetch(url)?;
    await response.text()
}

// Async runtime
mod std::async {
    fn block_on<F: Future>(future: F) -> F::Output
    fn spawn<F: Future>(future: F) -> JoinHandle<F::Output>
    fn sleep(duration: Duration) -> impl Future<Output = ()>
    
    struct JoinHandle<T> {
        fn await -> Result<T, Error>
        fn abort()
    }
    
    // Channels for async communication
    fn channel<T>(buffer: usize) -> (Sender<T>, Receiver<T>)
    
    struct Sender<T> {
        async fn send(value: T) -> Result<(), Error>
    }
    
    struct Receiver<T> {
        async fn recv() -> Option<T>
    }
}
```

## 11. Error Handling

**Current Status**: ⚠️ Basic Result type exists  
**Priority**: HIGH

```ruchy
// Result type with ? operator support
enum Result<T, E> {
    Ok(T),
    Err(E),
}

impl Result<T, E> {
    fn unwrap(self) -> T
    fn unwrap_or(self, default: T) -> T
    fn unwrap_or_else(self, f: fn() -> T) -> T
    fn expect(self, msg: String) -> T
    fn is_ok(&self) -> bool
    fn is_err(&self) -> bool
    fn map<U>(self, f: fn(T) -> U) -> Result<U, E>
    fn map_err<F>(self, f: fn(E) -> F) -> Result<T, F>
    fn and_then<U>(self, f: fn(T) -> Result<U, E>) -> Result<U, E>
}

// Option type
enum Option<T> {
    Some(T),
    None,
}

impl Option<T> {
    fn unwrap(self) -> T
    fn unwrap_or(self, default: T) -> T
    fn unwrap_or_else(self, f: fn() -> T) -> T
    fn expect(self, msg: String) -> T
    fn is_some(&self) -> bool
    fn is_none(&self) -> bool
    fn map<U>(self, f: fn(T) -> U) -> Option<U>
    fn and_then<U>(self, f: fn(T) -> Option<U>) -> Option<U>
    fn ok_or<E>(self, err: E) -> Result<T, E>
}

// Error trait
trait Error {
    fn message(&self) -> String
    fn source(&self) -> Option<&dyn Error>
}

// Panic handling
fn panic!(msg: String) -> !
fn unreachable!() -> !
fn todo!(msg: String) -> !
```

## 12. Collections

**Current Status**: ⚠️ Basic array support  
**Priority**: HIGH

```ruchy
mod std::collections {
    // HashMap
    struct HashMap<K, V> {
        fn new() -> HashMap<K, V>
        fn insert(&mut self, key: K, value: V) -> Option<V>
        fn get(&self, key: &K) -> Option<&V>
        fn get_mut(&mut self, key: &K) -> Option<&mut V>
        fn remove(&mut self, key: &K) -> Option<V>
        fn contains_key(&self, key: &K) -> bool
        fn len(&self) -> usize
        fn is_empty(&self) -> bool
        fn keys(&self) -> Iterator<&K>
        fn values(&self) -> Iterator<&V>
        fn iter(&self) -> Iterator<(&K, &V)>
    }
    
    // Vec (dynamic array)
    struct Vec<T> {
        fn new() -> Vec<T>
        fn with_capacity(capacity: usize) -> Vec<T>
        fn push(&mut self, value: T)
        fn pop(&mut self) -> Option<T>
        fn insert(&mut self, index: usize, value: T)
        fn remove(&mut self, index: usize) -> T
        fn get(&self, index: usize) -> Option<&T>
        fn len(&self) -> usize
        fn is_empty(&self) -> bool
        fn clear(&mut self)
        fn sort(&mut self)
        fn sort_by(&mut self, f: fn(&T, &T) -> Ordering)
        fn iter(&self) -> Iterator<&T>
        fn map<U>(&self, f: fn(T) -> U) -> Vec<U>
        fn filter(&self, f: fn(&T) -> bool) -> Vec<T>
        fn reduce<U>(&self, init: U, f: fn(U, T) -> U) -> U
    }
    
    // HashSet
    struct HashSet<T> {
        fn new() -> HashSet<T>
        fn insert(&mut self, value: T) -> bool
        fn remove(&mut self, value: &T) -> bool
        fn contains(&self, value: &T) -> bool
        fn len(&self) -> usize
        fn is_empty(&self) -> bool
        fn union(&self, other: &HashSet<T>) -> HashSet<T>
        fn intersection(&self, other: &HashSet<T>) -> HashSet<T>
        fn difference(&self, other: &HashSet<T>) -> HashSet<T>
    }
}
```

## 13. String Operations

**Current Status**: ⚠️ Basic string concatenation  
**Priority**: HIGH

```ruchy
impl String {
    fn len(&self) -> usize
    fn is_empty(&self) -> bool
    fn chars(&self) -> Iterator<char>
    fn bytes(&self) -> Iterator<u8>
    fn contains(&self, pattern: &str) -> bool
    fn starts_with(&self, pattern: &str) -> bool
    fn ends_with(&self, pattern: &str) -> bool
    fn find(&self, pattern: &str) -> Option<usize>
    fn rfind(&self, pattern: &str) -> Option<usize>
    fn split(&self, delimiter: &str) -> [String]
    fn split_once(&self, delimiter: &str) -> Option<(String, String)>
    fn trim(&self) -> String
    fn trim_start(&self) -> String
    fn trim_end(&self) -> String
    fn to_lowercase(&self) -> String
    fn to_uppercase(&self) -> String
    fn replace(&self, from: &str, to: &str) -> String
    fn repeat(&self, n: usize) -> String
    fn parse<T>(&self) -> Result<T, Error>
    
    // String interpolation (already exists)
    f"Hello, {name}!"
}
```

## 14. Compilation and Deployment

**Current Status**: ❌ Not Implemented  
**Priority**: CRITICAL

```ruchy
// CLI command
ruchy compile script.ruchy \
    --output binary \
    --target x86_64-unknown-linux-gnu \
    --release \
    --strip \
    --permissions read,write,net,env,run

// Programmatic API
mod std::compile {
    struct CompileOptions {
        entry: String,
        output: String,
        target: Target,
        release: bool,
        strip: bool,
        permissions: [Permission],
        icon: Option<String>,
        embed_assets: [String],
    }
    
    enum Target {
        Linux_x64,
        Linux_arm64,
        Windows_x64,
        MacOS_x64,
        MacOS_arm64,
    }
    
    fn compile(options: CompileOptions) -> Result<(), Error>
}
```

## 15. Package Management

**Current Status**: ❌ Not Implemented  
**Priority**: MEDIUM

```ruchy
// Package manifest (ruchy.toml)
[package]
name = "ubuntu-config"
version = "1.0.0"
authors = ["developer@example.com"]

[dependencies]
http = "0.2"
json = "1.0"
regex = "1.5"

[dev-dependencies]
test-utils = "0.1"

// CLI commands
ruchy add http@0.2
ruchy remove json
ruchy update
ruchy publish

// Import from packages
import http::client::fetch
import json::{parse, stringify}
```

## Implementation Priority Matrix

| Component | Priority | Current Status | Effort | Impact |
|-----------|----------|---------------|--------|--------|
| Process/Command Execution | CRITICAL | ❌ Not Implemented | High | Blocks 90% of scripts |
| File System Operations | CRITICAL | ❌ Not Implemented | High | Blocks 80% of scripts |
| Standard I/O | CRITICAL | ⚠️ Partial | Medium | Blocks interactive scripts |
| Environment Variables | HIGH | ❌ Not Implemented | Low | Blocks configuration |
| Path Operations | HIGH | ❌ Not Implemented | Medium | Blocks file manipulation |
| Error Handling | HIGH | ⚠️ Basic | Medium | Blocks robust scripts |
| JSON Serialization | HIGH | ❌ Not Implemented | Medium | Blocks config files |
| Testing Framework | HIGH | ⚠️ Basic | High | Blocks quality assurance |
| String Operations | HIGH | ⚠️ Basic | Medium | Blocks text processing |
| Collections | HIGH | ⚠️ Basic | High | Blocks data structures |
| Async Runtime | HIGH | ⚠️ Parser only | Very High | Blocks concurrent ops |
| Logging | MEDIUM | ⚠️ println only | Low | Quality of life |
| Regex | MEDIUM | ❌ Not Implemented | Medium | Text processing |
| Network I/O | MEDIUM | ❌ Not Implemented | High | Package management |
| Compilation | CRITICAL | ❌ Not Implemented | Very High | Blocks deployment |
| Package Management | MEDIUM | ❌ Not Implemented | Very High | Ecosystem growth |

## Migration Path

### Phase 1: Core System Operations (Week 1-2)
1. Implement `std::process::Command` for subprocess execution
2. Implement `std::fs` for file operations
3. Implement `std::env` for environment variables
4. Implement `std::io` for standard I/O

### Phase 2: Essential Libraries (Week 3-4)
1. Implement `std::path` for path manipulation
2. Enhance string operations
3. Implement JSON serialization
4. Improve error handling with Result/Option

### Phase 3: Testing and Quality (Week 5)
1. Enhance testing framework
2. Implement property-based testing
3. Add mocking capabilities
4. Implement logging framework

### Phase 4: Advanced Features (Week 6-8)
1. Implement async/await runtime
2. Add regex support
3. Implement collections (HashMap, Vec, HashSet)
4. Add network I/O

### Phase 5: Deployment (Week 9-10)
1. Implement compilation to binary
2. Add cross-compilation support
3. Implement package management
4. Create migration tools

## Testing Requirements

Every new API must include:
1. Unit tests with >90% coverage
2. Property-based tests for complex logic
3. Integration tests with real system calls
4. Performance benchmarks
5. Documentation with examples
6. Migration guide from Deno equivalent

## Backwards Compatibility

- All existing Ruchy syntax must continue to work
- New features should be additive, not breaking
- Deprecation cycle for any breaking changes
- Clear migration paths with tooling support

## Success Criteria

Ruchy can replace Deno when:
1. ✅ All 95 ubuntu-config-scripts can be rewritten in Ruchy
2. ✅ Scripts run with equal or better performance
3. ✅ Binary compilation produces <10MB executables
4. ✅ Cross-platform compilation works reliably
5. ✅ Testing framework supports property-based testing
6. ✅ Package ecosystem allows code reuse
7. ✅ Developer experience matches or exceeds Deno

## Conclusion

This specification represents a complete roadmap for Ruchy to become a production-ready systems programming language capable of replacing Deno TypeScript for system configuration and automation tasks. The implementation will require approximately 10 weeks of focused development, but will result in a powerful, type-safe, compiled language specifically designed for system operations.

The key advantages of Ruchy over Deno after implementation:
- **Compiled binaries**: No runtime dependency, faster execution
- **Type safety**: Compile-time guarantees prevent runtime errors
- **Native performance**: Direct system calls without JavaScript overhead
- **Property testing**: Built-in correctness verification
- **Actor model**: Better concurrency than JavaScript's event loop
- **Pattern matching**: More elegant error handling
- **Self-hosted**: Ruchy can compile itself

This is not just a port - it's an evolution toward a better systems programming language.