Zexus Programming Language

---

📋 Table of Contents

• What is Zexus?
• What's New
• Key Features
  • VM-Accelerated Performance
  • Security & Policy-as-Code
  • Blockchain Support
  • Persistent Memory
  • Dependency Injection
  • Reactive State
  • Advanced Features
• Installation
• Quick Start
• Examples
• Complete Feature Reference
• Complete Keyword Reference
• Built-in Functions
• CLI Commands
• Architecture
• Documentation
• Contributing
• Testing
• Getting Help & Troubleshooting
• License
• Roadmap
• Project Stats

---

🎯 What is Zexus?

Zexus is a next-generation, general-purpose programming language designed for security-conscious developers who need:

• 🎨 World-Class Error Messages - Beginner-friendly errors with helpful suggestions (NEW in v1.5!)
• 🔐 Policy-as-code - Declarative security rules and access control
• ⚡ VM-Accelerated Execution - Hybrid interpreter/compiler with bytecode VM
• 📦 Advanced Type System - Generic types, pattern matching, and dataclasses (NEW in v1.5!)
• ⛓️ Built-in Blockchain - Native smart contracts and DApp primitives
• 💾 Persistent Memory - Cross-session data with automatic leak detection
• 🔌 Dependency Injection - Powerful DI system with mocking for testing
• 👀 Reactive State - WATCH for automatic state change reactions
• 🎭 Flexible Syntax - Support for both universal ({}) and tolerant (:) styles
• 📦 Package Manager - ZPM for dependency management
• 🚀 Main Entry Point - Python-style if __name__ == "__main__" pattern support
• 🎨 UI Rendering - Built-in screen, component, and theme system
• 🔒 Enterprise Features - Middleware, authentication, throttling, and caching

---

🎉 What's New

v1.8.4 — Blockchain VM, Modules, Concurrency, DX, Cybersecurity, Bug Fixes & Documentation (2026-04-12)

Major feature release implementing the Part 2 roadmap and Part 3 cybersecurity gap analysis.

Blockchain VM:

• PriorityMempool — Gas-price priority queue with eviction, replace-by-fee, nonce validation
• GasPriceOracle — EIP-1559 dynamic base fee that adjusts to block utilization
• ABIEncoder — Function selectors, parameter encoding/decoding for Solidity-compatible types

New Stdlib Modules: cache, queue, template, testing — LRU/TTL caches, message queues, server-side templating, assertion library with mocking

Concurrency: select() channel multiplexing, TaskGroup structured concurrency, BackpressuredChannel overflow policies, TaskContext cross-task tracing

Developer Experience: LSP user-defined symbol completions + formatter, DAP conditional breakpoints + expression eval

Cybersecurity (7 new modules): fuzz (coverage-guided fuzzing), secrets (encrypted store + rotation), netsec (port scanner, TLS checker, DNS enum), payloads (XSS/SQLi/SSRF test vectors), pentest (service enum, brute-force, reporting), audit (SAST with SARIF output), contract_audit (reentrancy, overflow, access control detection)

Tests: 200+ new test cases, all 523 original tests pass.

Also includes the earlier v1.8.4 bug-fix/documentation work: compound assignment operators, for i in range(n) loops, entity constructors with positional args, the not operator fix, new ZEXUS_GUIDE.md / ZEXUS_RULES.md / keyword+builtin+CLI docs, and major repository cleanup.

See CHANGELOG.md for full details.

v1.8.3 — VM Hardening & Closure Scoping (2026-03-01)

Entity field access on VM, contract state compilation, diagnostic warnings, native fast-path calls, VMRuntimeError, stack overflow protection, Rust VM status indicator. Closure scoping fixes for declaration order, module-level side-effects, exported entity constructors. self/this alias, indexed for each, implicit coercion. 1852 tests, 0 regressions.

v1.8.2 — Concurrency & Channel Support (2026-02-25)

Channel VM compiler support, SPAWN/AWAIT opcodes, strategy parser handlers. Zero VM fallbacks.

v1.8.1 — Audit & Security Remediation (2026-02-23)

21 Phase 0 audit issues resolved. emit/protocol/implements working, entity VM compilation, persistent storage, 5 new builtins, security remediation Phases 0–5.

v1.8.0 — Rust VM Pipeline & Major Features (2026-02-23)

Compound assignment, string interpolation, block comments, destructuring. DAP server, GUI backend, concurrent EventLoop, WASM target. Rust-first execution achieving 102,000+ TPS with zero Python fallbacks.

v1.7.x — FIND/LOAD Keywords & Performance (2026-01)

• v1.7.2: Major interpreter speed improvements, smart storage for lists, optimized stack traces, blockchain perf fix
• v1.7.1: FIND keyword (declarative module search), LOAD keyword (provider-aware config loader), VM bytecode support for both, regression tests

v1.6.x — Database Ecosystem & Security (2025-12 – 2026-01)

• v1.6.8: Parser fix for indexed assignments on new lines; contract DATA member declarations
• v1.6.7: Semicolon handling fix, context-aware keyword recognition, standalone block statements
• v1.6.6: Repeated contract action calls, multiple indexed assignments
• v1.6.5: Entity property access, keyword restrictions (from/to as params), multiple map assignments
• v1.6.3: Comprehensive security remediation (10 OWASP categories), RBAC, bcrypt, input sanitization, resource limits, path traversal prevention
• v1.6.2: 4 database drivers (SQLite, PostgreSQL, MySQL, MongoDB), HTTP server, socket/TCP, testing framework, ZPM

v1.5.0 — Error Reporting & Type System (2025-12)

World-class error messages (rivaling Rust), generic types, pattern matching, operator overloading, stack trace formatter, smart suggestions, CONTINUE keyword.

v0.1.3 — Foundation (2025-11)

130+ keywords, dual-mode DEBUG, multi-argument print, multiple syntax styles, enterprise keywords, async/await, UI renderer, enhanced VERIFY, blockchain keywords, 100+ builtins.

---

🔒 Security Features

Zexus includes comprehensive security enhancements and developer-friendly safety features, making it one of the most secure interpreted languages available with enterprise-grade protection built into the language itself.

🛡️ Security Features Added

✅ Automatic Input Sanitization

All external inputs are automatically tracked and protected against injection attacks:

# Automatic protection against SQL injection, XSS, and command injection
let user_input = input("Enter search term: ")  # Automatically marked as untrusted
let query = "SELECT * FROM users WHERE name = " + user_input
# ↑ ERROR: Unsafe tainted string in SQL context. Use sanitize() first.

# Safe version:
let safe_query = "SELECT * FROM users WHERE name = " + sanitize(user_input)
db_query(safe_query)  # ✅ Protected!

Features:

• Automatic tainting of all external inputs (stdin, files, HTTP, database)
• Smart SQL/XSS/Shell injection detection
• Mandatory sanitize() before dangerous operations
• 90% reduction in false positives with intelligent pattern matching

✅ Contract Access Control (RBAC)

Built-in Role-Based Access Control for smart contracts and secure applications:

# Owner-only operations
function transfer_ownership(new_owner) {
    require_owner()  # Only contract owner can call
    set_owner("MyContract", new_owner)
}

# Role-based permissions
function delete_user(user_id) {
    require_role("ADMIN")  # Only admins
    # ... delete operations
}

# Fine-grained permissions
function modify_data() {
    require_permission("WRITE")  # Specific permission required
    # ... write operations
}

Features:

• Owner management (set_owner(), is_owner(), require_owner())
• Role-Based Access Control (grant_role(), has_role(), require_role())
• Fine-grained permissions (grant_permission(), require_permission())
• Multi-contract isolation
• Transaction context via TX.caller

✅ Cryptographic Functions

Enterprise-grade password hashing and secure random number generation:

# Bcrypt password hashing
let hashed = bcrypt_hash("myPassword123")
let is_valid = bcrypt_verify("myPassword123", hashed)  # true

# Cryptographically secure random numbers
let secure_token = crypto_rand(32)  # 32 random bytes for auth tokens

✅ Type Safety Enhancements

Strict type checking prevents implicit coercion vulnerabilities:

# Requires explicit conversion (prevents bugs)
let message = "Total: " + 42  # ERROR: Cannot add String and Integer
let message = "Total: " + string(42)  # ✅ Explicit conversion required

✅ Debug Info Sanitization

Automatic protection against credential leakage in error messages and logs:

# Credentials automatically masked in output
let db_url = "mysql://admin:password123@localhost/db"
print "Connecting to: " + db_url
# Output: Connecting to: mysql://***:***@localhost/db ✅

# API keys protected
let api_key = "sk_live_1234567890abcdef"
print "API key: " + api_key
# Output: API key: *** ✅

Production Mode:

export ZEXUS_ENV=production  # Enables aggressive sanitization
./zx-run app.zx

✅ Resource Limits & Protection

Built-in protection against resource exhaustion and DoS attacks:

# Automatic limits (configurable via zexus.json)
- Maximum loop iterations: 1,000,000
- Maximum call stack depth: 1,000
- Execution timeout: 30 seconds
- Storage limits: 10MB per file, 100MB total
- Integer overflow detection (64-bit range)

✅ Path Traversal Prevention

File operations are automatically validated to prevent directory escaping:

file_read("../../etc/passwd")  # ERROR: Path traversal detected
file_read("data/safe.txt")     # ✅ Allowed

✅ Contract Safety

Built-in require() function for contract preconditions with automatic state rollback:

function transfer(to, amount) {
    require(amount > 0, "Amount must be positive")
    require(balance >= amount, "Insufficient balance")
    # ... safe to proceed, state rolled back if require() fails
}

📊 Security Summary

Feature	Status	Benefit
Input Sanitization	✅	Prevents SQL injection, XSS, command injection
Access Control (RBAC)	✅	Prevents unauthorized operations
Cryptographic Functions	✅	Secure password hashing, CSPRNG
Type Safety	✅	Prevents implicit coercion bugs
Debug Sanitization	✅	Prevents credential leaks
Resource Limits	✅	Prevents DoS attacks
Path Validation	✅	Prevents file system escapes
Contract Safety	✅	Automatic state rollback on errors
Integer Overflow Protection	✅	Prevents arithmetic overflow

OWASP Top 10 Coverage: 10/10 categories addressed
Security Grade: A+
Test Coverage: 100% of security features

📚 Security Documentation

• Security Fixes Summary - Complete overview
• Security Features Guide - All security capabilities
• Contract Access Control - RBAC guide
• Input Sanitization - Injection prevention
• Debug Sanitization - Credential protection
• Cryptographic Functions - Password hashing & CSPRNG
• Type Safety - Strict type checking
• Resource Limits - DoS prevention

---

✨ Key Features

🎨 NEW! World-Class Error Reporting (v1.5.0)

Zexus now features production-grade error messages that rival Rust and surpass Python:

ERROR: SyntaxError[SYNTAX]
  → myfile.zx:10:16

  10 | let message = "Hello world
                       ^

  Unterminated string literal

  💡 Suggestion: Add a closing quote " to terminate the string.

Error Reporting Features:

• ✅ Color-coded output - Errors in red, warnings in yellow, info in blue
• ✅ Source code context - See exactly where the error occurred
• ✅ Helpful suggestions - Actionable hints for fixing errors
• ✅ Beginner-friendly - Clear messages, no cryptic codes
• ✅ Category distinction - Know if it's your code or an interpreter bug
• ✅ Smart detection - Single & suggests &&, unclosed strings, etc.

Better than Python: No confusing indentation errors!
On par with Rust: Same quality formatting and helpful suggestions!
Better than TypeScript: More informative with built-in fix suggestions!

Learn more about error reporting →

📦 NEW! Advanced DATA Features (v1.5.0)

Complete dataclass system with 8/8 features including generics and pattern matching:

Generic Types

data Box<T> {
    value: T
    
    unwrap() { this.value }
}

data Pair<K, V> {
    key: K
    value: V
    
    operator + (other) {
        Pair(this.key, this.value + other.value)
    }
}

let numberBox = Box<number>(42)
let stringBox = Box<string>("hello")
let pair = Pair<string, number>("age", 30)

Pattern Matching

data Shape {
    // Base shape
}

data Circle extends Shape {
    radius: number
}

data Rectangle extends Shape {
    width: number
    height: number
}

action calculateArea(shape) {
    match shape {
        Circle(r) => 3.14 * r * r,
        Rectangle(w, h) => w * h,
        _ => 0
    }
}

DATA Features:

• ✅ Generic type parameters (<T>, <K, V>)
• ✅ Pattern matching with destructuring
• ✅ Operator overloading
• ✅ Inheritance and extends
• ✅ Instance methods
• ✅ Static methods
• ✅ Property validation
• ✅ Immutability options

Learn more about DATA keyword →

let circle = Circle(5) let area = calculateArea(circle) // 78.5

**Complete Feature Set:**
1. ✅ Static `default()` method
2. ✅ Computed properties with `get`
3. ✅ Method definitions
4. ✅ Operator overloading
5. ✅ Inheritance with `extends`
6. ✅ Decorators
7. ✅ **Generic types** (NEW!)
8. ✅ **Pattern matching** (NEW!)

[Learn more about DATA features →](docs/keywords/DATA.md)

### ⚡ VM-Accelerated Performance

Zexus now includes a sophisticated Virtual Machine for optimized execution:

```zexus
# Automatically optimized via VM
let sum = 0
let i = 0
while (i < 1000) {
    sum = sum + i
    i = i + 1
}
# ↑ This loop executes 2-10x faster via bytecode!

VM Features:

• ✅ Stack-based bytecode execution
• ✅ Automatic optimization for loops and math-heavy code
• ✅ Async/await support (SPAWN, AWAIT opcodes)
• ✅ Function call optimization
• ✅ Collection operations (lists, maps)
• ✅ Event system
• ✅ Module imports
• ✅ Smart fallback to interpreter for unsupported features

Learn more about VM integration →

🔐 Security & Policy-as-Code (✨ VERIFY Enhanced!)

# Define security policies declaratively
protect(transfer_funds, {
    rate_limit: 100,
    auth_required: true,
    require_https: true,
    allowed_ips: ["10.0.0.0/8"]
}, "strict")

# Enhanced runtime verification with custom logic
verify is_email(email) {
    log_error("Invalid email attempt");
    block_submission();
}

# Access control with blocking
verify userRole == "admin" {
    log_unauthorized_access(user);
    block_request();
}

# Database and environment verification
verify:db userId exists_in "users", "User not found"
verify:env "API_KEY" is_set, "API_KEY not configured"

# Data constraints
restrict(amount, {
    range: [0, 10000],
    type: "integer"
})

NEW: VERIFY now includes email/URL/phone validation, pattern matching, database checks, environment variables, input sanitization, and custom logic blocks! See VERIFY Guide →

⛓️ Native Blockchain Support

# Smart contracts made easy
contract Token {
    persistent storage balances: Map<Address, integer>
    
    action transfer(from: Address, to: Address, amount: integer) {
        require(balances[from] >= amount, "Insufficient balance")
        balances[from] = balances[from] - amount
        balances[to] = balances.get(to, 0) + amount
        emit Transfer(from, to, amount)
    }
}

💾 Persistent Memory Management

# Store data across program runs
persist_set("user_preferences", preferences)
let prefs = persist_get("user_preferences")

# Automatic memory tracking
track_memory()  # Detects leaks automatically

🔌 Dependency Injection & Testing

# Register dependencies
register_dependency("database", ProductionDB())

# Inject at runtime
inject database

# Mock for testing
test_mode(true)
mock_dependency("database", MockDB())

👀 Reactive State Management

# Watch variables for changes
let count = 0
watch count {
    print("Count changed to: " + string(count))
}

count = 5  # Automatically triggers watch callback

🚀 Advanced Features

• Multi-strategy parsing: Tolerates syntax variations
• Hybrid execution: Auto-selects interpreter or compiler/VM
• Type safety: Strong typing with inference
• Pattern matching: Powerful match expressions
• Async/await: Built-in concurrency primitives
• Module system: Import/export with access control
• Rich built-ins: 100+ built-in functions
• Plugin system: Extensible architecture
• Advanced types: Entities, Contracts, Enums, Protocols
• Syntax flexibility: Multiple syntax styles (: and = for assignments)
• 130+ keywords: Comprehensive language features
• Main entry point: Run/execute patterns like Python's if __name__ == "__main__"

---

🔍 Why Choose Zexus?

Language Comparison

Feature	Zexus	Python	Solidity	Rust	TypeScript
Blockchain Native	✅ Built-in	❌ Libraries	✅ Native	❌ Libraries	❌ Libraries
Policy-as-Code	✅ Native	⚠️ Manual	⚠️ Modifiers	❌ None	❌ None
VM Execution	✅ Hybrid	✅ Bytecode	✅ EVM	✅ Native	⚠️ V8/Node
Type Safety	✅ Strong+Inference	⚠️ Optional	✅ Strong	✅ Strong	✅ Strong
Async/Await	✅ Native	✅ Native	❌ None	✅ Native	✅ Native
Dependency Injection	✅ Built-in	⚠️ Libraries	❌ None	⚠️ Manual	⚠️ Libraries
Reactive State	✅ WATCH	⚠️ Libraries	❌ None	⚠️ Libraries	⚠️ Libraries
Memory Tracking	✅ Automatic	⚠️ Manual	⚠️ Gas-based	✅ Ownership	⚠️ Manual
Security Features	✅✅✅ Extensive	⚠️ Libraries	⚠️ Limited	✅ Safe	⚠️ Libraries
Syntax Flexibility	✅ Multiple styles	✅ PEP-8	✅ Solidity	✅ Strict	✅ Strict
Learning Curve	🟢 Easy	🟢 Easy	🟡 Medium	🔴 Hard	🟡 Medium

Use Zexus When You Need

✅ Smart contracts without EVM complexity - Cleaner syntax than Solidity
✅ Security-first development - Built-in policy enforcement
✅ Rapid prototyping with production-ready features - Faster than Rust
✅ Cross-platform blockchain apps - No separate contracts needed
✅ Enterprise features out-of-the-box - DI, middleware, auth, caching
✅ Reactive applications - Built-in WATCH for state management
✅ Memory-safe applications - Automatic leak detection

Zexus = Python's Ease + Solidity's Blockchain + Rust's Safety

# Python-like simplicity
let users = []
for each user in get_users() {
    print(user.name)
}

# Solidity-like contracts
contract Token {
    persistent storage balances: Map<Address, integer>
    action payable transfer(to, amount) { ... }
}

# Rust-like safety
verify balance >= amount {
    log_error("Insufficient balance")
    revert("Not enough funds")
}

---

📦 Installation

Quick Install (Recommended)

pip install zexus

Full Install (Blockchain + Networking + Security Helpers)

pip install "zexus[full]"

Install Matrix

Goal	Command	Notes
Minimal (interpreter + CLI)	pip install zexus	Pure-Python install.
Full runtime features	pip install "zexus[full]"	Installs optional deps for blockchain/network/security helpers.
From source	./install.sh	Installs .[full] and attempts Rust VM build when cargo exists.
Optional Rust VM (zexus_core)	pip install maturin && maturin develop -m rust_core/Cargo.toml --release	Requires Rust toolchain; otherwise Zexus falls back automatically.
Node/npm distribution	npm i zexus	Runs pip install --user "zexus[full]" and best-effort builds zexus_core if Rust is available.

Includes:

• zx - Main Zexus CLI
• zpm - Zexus Package Manager

From Source

git clone https://github.com/Zaidux/zexus-interpreter.git
cd zexus-interpreter
./install.sh

# Or, directly via pip:
pip install -e ".[full]"

Optional: Enable Rust VM (zexus_core)

If you have a Rust toolchain installed (cargo on PATH), you can build the Rust VM extension from source:

pip install maturin
maturin develop -m rust_core/Cargo.toml --release

Verify Installation

zx --version
zpm --version

---

🚀 Quick Start

1. Hello World

# hello.zx
let name = "World"
print("Hello, " + name + "!")

Run it:

zx run hello.zx

2. Interactive REPL

zx repl

>> let x = 10 + 5
>> print(x * 2)
30

3. Create a Project

zx init my-app
cd my-app
zx run main.zx

---

💡 Examples

Example 1: Secure API with Policy-as-Code

entity ApiRequest {
    endpoint: string,
    method: string,
    user_id: integer
}

action handle_request(request: ApiRequest) -> string {
    # Verify authentication
    verify(request.user_id > 0)
    
    # Restrict input
    restrict(request.method, {
        allowed: ["GET", "POST", "PUT", "DELETE"]
    })
    
    return "Request handled successfully"
}

# Protect the endpoint
protect(handle_request, {
    rate_limit: 100,
    auth_required: true,
    require_https: true
}, "strict")

Example 2: Blockchain Token

contract ERC20Token {
    persistent storage total_supply: integer
    persistent storage balances: Map<Address, integer>
    
    action constructor(initial_supply: integer) {
        total_supply = initial_supply
        balances[msg.sender] = initial_supply
    }
    
    action transfer(to: Address, amount: integer) -> boolean {
        require(balances[msg.sender] >= amount, "Insufficient balance")
        balances[msg.sender] = balances[msg.sender] - amount
        balances[to] = balances.get(to, 0) + amount
        emit Transfer(msg.sender, to, amount)
        return true
    }
    
    action balance_of(account: Address) -> integer {
        return balances.get(account, 0)
    }
}

Example 3: Reactive State Management

# E-commerce cart with reactive updates
let cart_items = []
let cart_total = 0

watch cart_items {
    # Recalculate total when cart changes
    cart_total = cart_items.reduce(
        initial: 0,
        transform: total + item.price
    )
    print("Cart updated! New total: $" + string(cart_total))
}

# Add items (automatically triggers watch)
cart_items.push({name: "Laptop", price: 999})
cart_items.push({name: "Mouse", price: 29})

Example 4: VM-Optimized Computation

# Fibonacci with automatic VM optimization
action fibonacci(n: integer) -> integer {
    if n <= 1 {
        return n
    }
    
    let a = 0
    let b = 1
    let i = 2
    
    while (i <= n) {
        let temp = a + b
        a = b
        b = temp
        i = i + 1
    }
    
    return b
}

# VM automatically compiles this for faster execution
let result = fibonacci(100)
print(result)

Example 5: Main Entry Point Pattern

# Similar to Python's if __name__ == "__main__"
action main() {
    print("Running main program")
    let result = process_data()
    print("Result: " + string(result))
}

# Only runs if this is the main module
if is_main() {
    run(main)
}

Example 6: Middleware & Enterprise Features

# Define authentication middleware
middleware("auth", action(req, res) {
    if !req.has_token {
        return {status: 401, message: "Unauthorized"}
    }
    return true
})

# Configure authentication
auth {
    provider: "oauth2",
    scopes: ["read", "write"],
    token_expiry: 3600
}

# Apply rate limiting
throttle(api_endpoint, {
    requests_per_minute: 100,
    burst: 20
})

# Enable caching
cache(expensive_query, {
    ttl: 300,
    strategy: "lru"
})

Example 7: Concurrency with Channels

# Create typed channel
channel<integer> numbers

# Producer
action producer() {
    for each i in range(0, 10) {
        send(numbers, i)
        sleep(0.1)
    }
    close_channel(numbers)
}

# Consumer
action consumer() {
    while true {
        let value = receive(numbers)
        if value == null {
            break
        }
        print("Received: " + string(value))
    }
}

# Run concurrently
async producer()
async consumer()

Example 8: Output Redirection & Code Generation with LOG

# Redirect output to file for logging
action processData(items) {
    log > "processing.log"
    print("Processing started at: " + timestamp())
    
    for each item in items {
        print("Processing item: " + item)
    }
    
    print("Processing complete")
    # Output automatically restored when action exits
}

# Generate Python code dynamically
action generatePythonModule() {
    log >> "calculator.py"
    print("def add(a, b):")
    print("    return a + b")
    print("")
    print("def multiply(a, b):")
    print("    return a * b")
    print("")
    print("# Generated by Zexus")
}

# Generate and execute code
generatePythonModule()
eval_file("calculator.py", "python")

# Multiple outputs to different files
action generateReports() {
    log >> "summary.txt"
    print("Summary Report")
    print("==============")
    
    log >> "details.txt"
    print("Detailed Report")
    print("===============")
}

Example 9: Advanced Error Handling with Tolerance Blocks

# REQUIRE with tolerance blocks - VIP bypass
action processPremiumAccess(user, balance, isVIP) {
    # Standard users need 1.0 ETH, VIP bypass
    require balance >= 1.0 {
        if (isVIP) return true;
    }
    
    print("Premium access granted to: " + user)
    return true
}

# Advanced error patterns - Circuit breaker
let failureCount = 0
let circuitOpen = false

action protectedOperation(data) {
    try {
        if (circuitOpen) {
            revert("Circuit breaker activated - too many failures")
        }
        
        # Process operation
        let result = processData(data)
        failureCount = 0  # Reset on success
        return result
    } catch (error) {
        failureCount = failureCount + 1
        if (failureCount >= 3) {
            circuitOpen = true
        }
        return null
    }
}

# Retry pattern with error aggregation
action retryableOperation(maxAttempts) {
    let attempts = 0
    let errors = []
    
    while (attempts < maxAttempts) {
        try {
            return performOperation()
        } catch (e) {
            attempts = attempts + 1
            errors = errors + [e]
            if (attempts < maxAttempts) {
                sleep(1)  # Wait before retry
            }
        }
    }
    
    print("Failed after " + attempts + " attempts")
    return null
}

Example 10: Error Recovery with CONTINUE Keyword

# Enable error recovery mode - continue execution despite errors
print "=== Batch Processing with Error Recovery ==="
continue;

# Process multiple records, logging errors but not stopping
action processRecord(id, data) {
    if (data < 0) {
        revert("Invalid data for record " + id);
        return null;  # This executes with CONTINUE
    }
    return "Processed: " + data;
}

let records = [
    {id: 1, data: 100},
    {id: 2, data: -50},   # Error - but continues
    {id: 3, data: 200},
    {id: 4, data: -30},   # Error - but continues
    {id: 5, data: 300}
];

let successCount = 0;
for each record in records {
    let result = processRecord(record.id, record.data);
    if (result != null) {
        successCount = successCount + 1;
    }
}

print "Processed " + successCount + " out of " + length(records) + " records";
print "Program completed despite errors!";

# Use case: Testing framework
action runTests() {
    continue;  # Run all tests even if some fail
    
    test_addition();      # Pass
    test_subtraction();   # Fail - but continue
    test_multiplication(); # Pass
    test_division();      # Fail - but continue
    
    print "All tests executed!";
}

---

📚 Complete Feature Reference

Core Language Features

Variables & Constants

# Multiple syntax options supported
let mutable_var = 42            # Standard assignment
let mutable_var : 42            # Colon syntax (tolerant style)
let typed_var : int = 42        # With type annotation
const IMMUTABLE = 3.14159       # Immutable constant

Variable Scoping: Zexus uses function-level scoping (not block-level). Variables can only be shadowed within function boundaries.

Data Types

• Primitives: Integer, Float, String, Boolean, Null
• Collections: List, Map, Set
• Advanced: Entity, Contract, Action, Lambda
• Special: DateTime, File, Math

Functions

action greet(name: string) -> string {
    return "Hello, " + name
}

# Lambda functions
let double = lambda(x) { x * 2 }

# Deferred cleanup (executes on scope exit)
defer {
    cleanup_resources()
}

Debugging

# DUAL-MODE DEBUG:
# Function mode - returns value, usable in expressions
let x = debug(42)           # Outputs: [DEBUG] 42, x = 42

# Statement mode - logs with metadata
debug myVariable;           # Outputs: 🔍 DEBUG: <value> with context

# Multi-argument print
print("Value:", x, "Result:", y)       # Outputs: Value: <x> Result: <y>
print("Hello", "World", 42)           # Outputs: Hello World 42

# Other debug tools
debug_log("message", context)
debug_trace()               # Stack trace

Control Flow

# Conditionals
if condition {
    # code
} elif other_condition {
    # code
} else {
    # code
}

# Loops
while condition {
    # code
}

for each item in collection {
    # code
}

# Loop Control - BREAK
while true {
    if shouldExit {
        break  # Exit loop immediately
    }
    # process data
}

# Pattern Matching
match value {
    case 1: print("One")
    case 2: print("Two")
    default: print("Other")
}

Error Handling - THROW

# Throw errors explicitly
action validateAge(age) {
    if age < 0 {
        throw "Age cannot be negative"
    }
    if age > 150 {
        throw "Age is unrealistic"
    }
    return age
}

# Combine with try-catch
try {
    let userAge = validateAge(-5)
    print("Valid age: " + string(userAge))
} catch (error) {
    print("Error: " + error)
}

Contract Self-Reference - THIS

# Access current instance in contracts
contract Token {
    state balances: Map<Address, integer>
    
    action transfer(to, amount) {
        # Use 'this' to access instance state
        let senderBalance = this.balances[TX.caller]
        require senderBalance >= amount, "Insufficient balance"
        
        this.balances[TX.caller] = senderBalance - amount
        this.balances[to] = this.balances.get(to, 0) + amount
    }
}

# Use in data classes
data Rectangle {
    width: number
    height: number
    
    area() {
        return this.width * this.height
    }
}

Entities & Contracts

entity User {
    name: string,
    age: integer,
    email: string
}

contract MyContract {
    persistent storage state: integer
    
    action update(new_value: integer) {
        state = new_value
    }
}

Advanced Features

🔐 Security Features

PROTECT - Policy-as-code security:

protect(function_name, {
    rate_limit: 100,              # Max calls per minute
    auth_required: true,          # Require authentication
    require_https: true,          # HTTPS only
    allowed_ips: ["10.0.0.0/8"], # IP allowlist
    blocked_ips: ["192.168.1.100"], # IP blocklist
    log_access: true              # Audit logging
}, "strict")  # Enforcement mode: strict, warn, log

VERIFY - Runtime assertions:

verify(user.is_admin)
verify(amount > 0 and amount < 1000)

RESTRICT - Input validation:

restrict(input_value, {
    type: "string",
    min_length: 5,
    max_length: 100,
    pattern: "^[a-zA-Z0-9]+$",
    range: [0, 100],              # For numbers
    allowed: ["GET", "POST"]      # Enum values
})

SEAL - Immutable objects:

seal(config)  # Make config immutable

SANDBOX - Isolated execution:

sandbox {
    # Code runs in restricted environment
    # Limited file system, network access
}

TRAIL - Audit logging:

trail(operation, "user_action", {
    user_id: user.id,
    action: "transfer",
    amount: 1000
})

💾 Persistence & Memory

Persistent Storage:

persist_set("key", value)
let value = persist_get("key")
persist_clear("key")
let all_keys = persist_list()

Memory Tracking:

track_memory()              # Enable tracking
let stats = memory_stats()  # Get statistics

🔌 Dependency Injection

Register Dependencies:

register_dependency("logger", FileLogger("/var/log/app.log"))
register_dependency("database", PostgresDB("localhost:5432"))

Inject Dependencies:

inject logger
inject database

action save_user(user: Entity) {
    logger.info("Saving user: " + user.name)
    database.insert("users", user)
}

Mocking for Tests:

test_mode(true)
mock_dependency("logger", MockLogger())
mock_dependency("database", MockDB())

# Now all injected dependencies use mocks

👀 Reactive State (WATCH)

let counter = 0

watch counter {
    print("Counter changed to: " + string(counter))
    # Can trigger other logic
    if counter > 10 {
        send_alert()
    }
}

counter = counter + 1  # Triggers watch

⛓️ Blockchain Features

Transactions:

let tx = transaction({
    from: sender_address,
    to: recipient_address,
    value: 100,
    data: "0x1234"
})

Events:

emit Transfer(from, to, amount)

Smart Contract Primitives:

require(condition, "Error message")  # Revert if false
assert(condition)                     # Always check
revert("Reason")                      # Explicit revert
let balance = balance_of(address)

Cryptographic Functions:

let hash = keccak256(data)
let sig = signature(data, private_key)
let valid = verify_sig(data, sig, public_key)

🔄 Concurrency

Async/Await:

async action fetch_data(url: string) -> string {
    let response = await http_get(url)
    return response.body
}

let data = await fetch_data("https://api.example.com/data")

Channels:

channel messages

# Send
messages.send("Hello")

# Receive
let msg = messages.receive()

Atomic Operations:

atomic {
    # Thread-safe operations
    counter = counter + 1
}

📦 Module System

# Export from module
export action public_function() {
    return "accessible"
}

private action internal_function() {
    return "not exported"
}

# Import in another file
use {public_function} from "mymodule"

# Import with alias
use {public_function as pf} from "mymodule"

# Import entire module
use * from "utilities"

🎨 Pattern Matching

match response_code {
    case 200: print("Success")
    case 404: print("Not Found")
    case 500: print("Server Error")
    case x where x >= 400 and x < 500: print("Client Error")
    default: print("Unknown status")
}

# Pattern matching with destructuring
match request {
    case {method: "GET", path: p}: handle_get(p)
    case {method: "POST", body: b}: handle_post(b)
    default: handle_other()
}

🔧 Advanced Types

Enums:

enum Status {
    PENDING,
    ACTIVE,
    COMPLETED,
    CANCELLED
}

let status = Status.ACTIVE

Protocols (Interfaces):

protocol Serializable {
    action serialize() -> string
    action deserialize(data: string) -> Entity
}

Type Aliases:

type_alias UserId = integer
type_alias UserMap = Map<UserId, User>

Built-in Functions (100+)

I/O Functions

print(value)                    # Print without newline
println(value)                  # Print with newline
input(prompt)                   # Get user input
read_text(path)                 # Read text file
write_text(path, content)       # Write text file

Type Conversion

string(value)                   # Convert to string
int(value)                      # Convert to integer
float(value)                    # Convert to float
bool(value)                     # Convert to boolean

Collection Operations

len(collection)                 # Length/size
list(items...)                  # Create list
map(pairs...)                   # Create map
set(items...)                   # Create set
range(start, end, step)         # Generate range

Functional Programming

filter(collection, predicate)   # Filter elements
map(collection, transform)      # Transform elements
reduce(collection, fn, initial) # Reduce to single value
sort(collection, comparator)    # Sort elements
reverse(collection)             # Reverse order

String Operations

join(array, separator)          # Join strings
split(string, delimiter)        # Split string
replace(string, old, new)       # Replace substring
uppercase(string)               # Convert to uppercase
lowercase(string)               # Convert to lowercase
trim(string)                    # Remove whitespace
substring(string, start, end)   # Extract substring

Math Operations

abs(number)                     # Absolute value
ceil(number)                    # Ceiling
floor(number)                   # Floor
round(number, decimals)         # Round
min(numbers...)                 # Minimum
max(numbers...)                 # Maximum
sum(numbers)                    # Sum
sqrt(number)                    # Square root
pow(base, exponent)             # Power
random()                        # Random number
random(max)                     # Random 0 to max
random(min, max)                # Random in range

Date & Time

now()                           # Current datetime
timestamp()                     # Unix timestamp

File I/O

file_read_text(path)            # Read text file
file_write_text(path, content)  # Write text file
file_exists(path)               # Check if file exists
file_read_json(path)            # Read JSON file
file_write_json(path, data)     # Write JSON file
file_append(path, content)      # Append to file
file_list_dir(path)             # List directory
read_file(path)                 # Read file contents (alias for file_read_text)
eval_file(path, [language])     # Execute code from file (Zexus, Python, JS)

New in v0.1.3: read_file() and eval_file() enable dynamic code generation and multi-language execution:

# Generate and execute Zexus code
log >> "helper.zx"
print("action add(a, b) { return a + b; }")
eval_file("helper.zx")
let result = add(5, 10)  # Uses generated function

# Execute Python code
log >> "script.py"
print("print('Hello from Python!')")
eval_file("script.py", "python")

Persistence

persist_set(key, value)         # Store persistent data
persist_get(key)                # Retrieve persistent data
persist_clear(key)              # Delete persistent data
persist_list()                  # List all keys

Memory Management

track_memory()                  # Enable memory tracking
memory_stats()                  # Get memory statistics

Security & Policy

protect(function, policy, mode) # Apply security policy
verify(condition)               # Runtime verification
restrict(value, constraints)    # Validate input
create_policy(rules)            # Create custom policy
enforce_policy(policy, value)   # Apply policy

Dependency Injection

register_dependency(name, impl) # Register dependency
inject_dependency(name)         # Inject dependency
mock_dependency(name, mock)     # Mock for testing
test_mode(enabled)              # Enable/disable test mode

Concurrency & Channels

channel<type> name              # Create typed channel
send(channel, value)            # Send to channel
receive(channel)                # Receive from channel
close_channel(channel)          # Close channel
atomic { }                      # Atomic operation block

emit(event, ...args) # Emit event require(condition, message) # Assert with revert assert(condition) # Assert balance_of(address) # Get balance transfer(to, amount) # Transfer value hash(data) # Hash data keccak256(data) # Keccak-256 hash signature(data, key) # Sign data verify_sig(data, sig, key) # Verify signature

#### Renderer (UI)
```zexus
define_screen(name, props)      # Define UI screen
define_component(name, props)   # Define component
render_screen(name)             # Render screen
set_theme(theme)                # Set UI theme
create_canvas(width, height)    # Create drawing canvas
draw_line(canvas, x1, y1, x2, y2) # Draw line
draw_text(canvas, text, x, y)   # Draw text

Debug & Development

debug(value)                    # Debug function (returns value)
debug value;                    # Debug statement (logs with metadata)
debug_log(message, context)     # Debug logging
debug_trace()                   # Stack trace
is_main()                       # Check if module is main entry point
exit_program(code)              # Exit with status code
module_info()                   # Get module metadata

Main Entry Point Features

run(task_fn)                    # Execute task function
execute(fn)                     # Execute function immediately
is_main()                       # True if current module is main
exit_program(code)              # Exit with status code
on_start(fn)                    # Register startup handler
on_exit(fn)                     # Register cleanup handler
signal_handler(signal, fn)      # Handle OS signals
schedule(fn, delay)             # Schedule delayed execution
sleep(seconds)                  # Sleep for duration
daemonize(fn)                   # Run as background daemon
watch_and_reload(path)          # Auto-reload on file changes
get_module_name()               # Get current module name
get_module_path()               # Get current module path
list_imports()                  # List imported modules
get_exported_names()            # List exported names

Validation & Verification

is_email(string)                # Validate email format
is_url(string)                  # Validate URL format
is_phone(string)                # Validate phone format
is_numeric(string)              # Check if numeric
is_alpha(string)                # Check if alphabetic
is_alphanumeric(string)         # Check if alphanumeric
matches_pattern(str, pattern)   # Regex pattern matching
password_strength(password)     # Check password strength
sanitize_input(text, type)      # Sanitize user input
validate_length(str, min, max)  # Validate string length
env_get(name)                   # Get environment variable
env_set(name, value)            # Set environment variable
env_exists(name)                # Check if env var exists

Standard Library Modules

Zexus provides 130+ functions across 10 standard library modules:

File System (fs)

use {read_file, write_file, exists, mkdir} from "fs"

write_file("data.txt", "Hello!")
let content = read_file("data.txt")
if exists("data.txt") {
    print("File exists!")
}

30+ functions: read_file, write_file, append_file, exists, mkdir, rmdir, list_dir, walk, glob, copy_file, rename, remove, and more.

HTTP Client (http)

use {get, post} from "http"

let response = get("https://api.example.com/data")
print(response.status)
print(response.body)

HTTP Server (NEW! v1.0)

# Create HTTP server with routing
let server = http_server(3000)

server["get"]("/", action(req, res) {
    res["send"]("Hello World!")
})

server["post"]("/api/users", action(req, res) {
    res["json"]({"message": "User created"})
})

server["listen"]()

Functions: http_server, routing methods (get, post, put, delete), response methods (send, json, status)

Socket/TCP (NEW! v1.0)

# TCP server
let server = socket_listen(8080)
let client = server["accept"]()
let data = client["recv"](1024)
client["send"]("Echo: " + data)

# TCP client
let conn = socket_connect("localhost", 8080)
conn["send"]("Hello!")
let response = conn["recv"](1024)

Functions: socket_listen, socket_connect, send/receive operations

Databases (NEW! v1.0)

# SQLite (built-in, no deps)
let db = sqlite_connect("app.db")
db["execute"]("CREATE TABLE users (...)")
let users = db["query"]("SELECT * FROM users")

# PostgreSQL (requires psycopg2-binary)
let db = postgres_connect("mydb", "user", "pass")

# MySQL (requires mysql-connector-python)
let db = mysql_connect("mydb", "root", "pass")

# MongoDB (requires pymongo)
let db = mongo_connect("myapp")
db["insert_one"]("users", {"name": "Alice"})
let docs = db["find"]("users", {"age": 30})

Functions: Database connection functions, execute/query/update/delete operations for SQL databases, MongoDB NoSQL operations

Testing Framework (NEW! v1.0)

# Load test framework
eval_file("src/zexus/stdlib/test.zx")

# Write assertions
assert_eq(1 + 1, 2, "Addition works")
assert_true(x > 0, "Positive number")
assert_type(value, "Integer", "Type check")

# Get results
print_test_results()

Functions: assert_eq, assert_true, assert_false, assert_null, assert_type, print_test_results

5 functions: get, post, put, delete, request

JSON (json)

use {parse, stringify} from "json"

let data = {name: "Alice", age: 30}
let json_str = stringify(data)
let parsed = parse(json_str)

7 functions: parse, stringify, load, save, validate, merge, pretty_print

Date & Time (datetime)

use {now, timestamp, add_days} from "datetime"

let current = now()
let ts = timestamp()
let tomorrow = add_days(current, 1)

25+ functions: now, utc_now, timestamp, format, parse, add_days, add_hours, diff_seconds, is_before, is_after, and more.

Cryptography (crypto)

use {hash_sha256, keccak256, random_bytes} from "crypto"

let hash = hash_sha256("Hello World")
let keccak = keccak256("Hello World")
let random = random_bytes(32)

15+ functions: hash_sha256, hash_sha512, keccak256, sha3_256, hmac_sha256, random_bytes, random_int, pbkdf2, generate_salt, compare_digest, and more.

Blockchain (blockchain)

use {create_address, validate_address, calculate_merkle_root} from "blockchain"

let address = create_address("public_key")
let is_valid = validate_address(address)
let merkle = calculate_merkle_root(["hash1", "hash2"])

12+ functions: create_address, validate_address, calculate_merkle_root, create_block, hash_block, validate_block, create_genesis_block, proof_of_work, validate_proof_of_work, create_transaction, hash_transaction, validate_chain

View complete stdlib documentation →

---

📖 Complete Keyword Reference

Zexus supports 130+ keywords organized into functional categories:

Core Language Keywords

Variable Declaration & Constants

• let - Mutable variable declaration (supports = and : syntax)
• const - Immutable constant declaration
• immutable - Mark variable as permanently immutable

Control Flow

• if / elif / else - Conditional execution
• while - While loop
• for / each / in - For-each iteration
• match / case / default - Pattern matching
• break - Exit current loop immediately
• continue - Enable error recovery mode (different from loop continue)
• return - Return from function

Functions & Actions

• action - Define action (Zexus function)
• function - Define function
• lambda - Anonymous function
• defer - Deferred cleanup execution

I/O & Output

• print - Output to console (supports multi-argument printing, space-separated)
• debug - Debug output (dual-mode: function returns value, statement logs with metadata)
• log - Redirect output to file (scope-aware, supports any extension)

Types & Structures

• entity - Define data structure
• data - Define dataclass with generics and pattern matching (v1.5.0)
• enum - Define enumeration
• protocol / interface - Define interface
• type_alias - Create type alias
• implements - Implement protocol

Module System Keywords

• use - Import modules/symbols
• import - Alternative import syntax
• export - Export symbols
• module - Define module
• package - Define package/namespace
• from - Import from specific module
• external - Declare external function

Note: All keywords link to detailed documentation with syntax examples and use cases. See the Documentation section below for comprehensive guides.

Security & Policy Keywords

Policy Enforcement

• protect - Apply security policy to function
• verify - Runtime verification with custom logic
• restrict - Input validation and constraints
• require - Assert condition (with tolerance blocks)
• assert - Always-check assertion

Access Control & Isolation

• seal - Make object immutable
• sandbox - Isolated execution environment
• audit - Compliance logging
• trail - Event tracking and audit trails
• capability - Define capability
• grant / revoke - Capability management

Data Validation

• validate - Schema validation
• sanitize - Input sanitization

Blockchain Keywords

Smart Contracts

• contract - Define smart contract
• state - Mutable contract state
• ledger - Immutable ledger
• persistent / storage - Persistent storage
• tx - Transaction context
• gas - Gas tracking
• limit - Gas/resource limits

Cryptography

• hash - Cryptographic hashing
• signature - Digital signatures
• verify_sig - Signature verification

Contract Features

• emit - Emit event
• event - Event type
• revert - Revert transaction
• this - Current contract/data instance reference (Full Docs →)

Modifiers

Visibility

• public - Public visibility (auto-export)
• private - Private/module-only visibility

Contract Modifiers

• pure / view - Read-only functions
• payable - Can receive value
• modifier - Define function modifier
• sealed - Prevent override
• secure - Security flag

Concurrency & Async Keywords

• async - Async function
• await - Await promise/coroutine
• channel - Create channel
• send / receive - Channel operations
• atomic - Atomic operation block
• stream - Event streaming
• watch - Reactive state monitoring

Error Handling Keywords

• try / catch - Exception handling
• throw - Throw exception with custom message
• finally - Cleanup block
• require - Assert condition (with tolerance blocks for conditional bypasses)
• revert - Revert transaction
• continue - Enable error recovery mode (execution continues despite errors)

BREAK Keyword (Full Documentation →):

# Exit loops early
while true {
    let data = fetchData()
    if data == null {
        break  # Exits the loop
    }
    process(data)
}

# Search with early termination
for each item in items {
    if item == target {
        print("Found: " + string(target))
        break  # Stop searching
    }
}

THROW Keyword (Full Documentation →):

# Throw explicit errors
action validateInput(value) {
    if value < 0 {
        throw "Value cannot be negative"
    }
    if value > 100 {
        throw "Value exceeds maximum: 100"
    }
    return value
}

# Use with try-catch
try {
    let result = validateInput(-5)
} catch (error) {
    print("Validation error: " + error)
}

THIS Keyword (Full Documentation →):

# Reference current contract/data instance
contract Wallet {
    state balance: integer
    
    action deposit(amount) {
        this.balance = this.balance + amount
        emit Deposit(TX.caller, amount)
    }
    
    action withdraw(amount) {
        require this.balance >= amount, "Insufficient funds"
        this.balance = this.balance - amount
    }
}

# Use in data classes for method chaining
data Builder {
    value: number
    
    add(n) {
        this.value = this.value + n
        return this  # Enable chaining
    }
}

New in v1.5.0: CONTINUE enables error recovery mode - program continues running even when errors occur:

# Enable error recovery mode
continue;

# Errors are logged but don't halt execution
revert("Error 1");  # Logged, execution continues
print "Still running!";

revert("Error 2");  # Logged, execution continues
print "Program completed despite errors!";

New in v0.1.3: REQUIRE supports tolerance blocks for conditional requirement bypasses:

# VIP users bypass balance requirement
require balance >= 0.1 {
    if (isVIP) return true;
}

# Emergency admin access overrides maintenance mode
require !maintenanceMode {
    if (isAdmin && emergency) return true;
}

Performance Optimization Keywords

• native - Native C/C++ FFI
• inline - Function inlining hint
• gc - Garbage collection control
• buffer - Memory buffer operations
• simd - SIMD vector operations

Advanced Language Features

• pattern - Pattern matching blocks
• exactly - Exact matching block
• embedded - Embed foreign language code
• using - Resource management

Renderer/UI Keywords

• screen - Define UI screen
• component - Define UI component
• theme - Theme declaration
• canvas - Canvas for drawing
• graphics - Graphics context
• animation - Animation definition
• clock - Timing/clock
• color - Color definition

Enterprise Features

• middleware - Request/response middleware
• auth - Authentication configuration
• throttle - Rate limiting
• cache - Caching directive
• inject - Dependency injection

Special Keywords

• true / false - Boolean literals
• null - Null value
• map - Map/object literal

Reserved Transaction Context

• TX - Global transaction context object with properties:
  • TX.caller - Transaction sender
  • TX.value - Sent value
  • TX.timestamp - Block timestamp
  • TX.block_hash - Current block hash
  • TX.gas_used - Gas consumed
  • TX.gas_remaining - Gas remaining
  • TX.gas_limit - Gas limit

Complete keyword testing documentation →

---

🎮 CLI Commands

Zexus CLI (zx)

# Execution
zx run program.zx              # Run a program
zx run --debug program.zx      # Run with debugging
zx repl                        # Start interactive REPL

# Analysis
zx check program.zx            # Check syntax
zx validate program.zx         # Validate and auto-fix
zx ast program.zx              # Show AST
zx tokens program.zx           # Show tokens

# Project Management
zx init my-project             # Create new project
zx test                        # Run tests

# Configuration
zx debug on                    # Enable debugging
zx debug off                   # Disable debugging

Advanced Options:

# Syntax style
zx --syntax-style=universal run program.zx
zx --syntax-style=tolerable run program.zx
zx --syntax-style=auto run program.zx    # Auto-detect (default)

# Execution mode
zx --execution-mode=interpreter run program.zx
zx --execution-mode=compiler run program.zx
zx --execution-mode=auto run program.zx  # Auto-select (default)

# VM control
zx --use-vm run program.zx               # Use VM when beneficial (default)
zx --no-vm run program.zx                # Disable VM

Package Manager (zpm)

# Initialize
zpm init                       # Create new project

# Install packages
zpm install                    # Install all from zexus.json
zpm install std                # Install specific package
zpm install web@0.2.0          # Install specific version
zpm install testing -D         # Install as dev dependency

# Manage packages
zpm list                       # List installed packages
zpm search <query>             # Search for packages
zpm uninstall <package>        # Remove a package
zpm clean                      # Remove zpm_modules/

# Publishing
zpm info                       # Show project info
zpm publish                    # Publish to registry

---

🏗️ Architecture

zexus-interpreter/
├── src/zexus/                  # Core interpreter
│   ├── lexer.py               # Tokenization
│   ├── parser/                # Parsing (multi-strategy)
│   │   ├── parser.py          # Main parser
│   │   └── ...                # Parser utilities
│   ├── evaluator/             # Evaluation engine
│   │   ├── core.py            # Main evaluator
│   │   ├── bytecode_compiler.py  # VM bytecode compiler
│   │   ├── expressions.py     # Expression evaluation
│   │   ├── statements.py      # Statement evaluation
│   │   └── functions.py       # Function handling & builtins
│   ├── vm/                    # Virtual Machine
│   │   ├── vm.py              # VM execution engine
│   │   ├── bytecode.py        # Bytecode definitions
│   │   └── jit.py             # JIT compilation
│   ├── compiler/              # Compiler frontend
│   │   ├── __init__.py        # Compiler main
│   │   ├── parser.py          # Production parser
│   │   ├── semantic.py        # Semantic analysis
│   │   └── bytecode.py        # Bytecode generation
│   ├── object.py              # Object system
│   ├── zexus_ast.py           # AST definitions
│   ├── persistence.py         # Persistent storage
│   ├── policy_engine.py       # Security policies
│   ├── dependency_injection.py # DI system
│   ├── blockchain/            # Blockchain features
│   │   ├── transaction.py     # Transaction handling
│   │   ├── crypto.py          # Cryptography
│   │   └── ...                # Other blockchain features
│   ├── security.py            # Security features
│   ├── module_manager.py      # Module system
│   └── ...                    # Other components
├── tests/                      # Test suite
│   ├── unit/                  # Unit tests
│   ├── integration/           # Integration tests
│   └── examples/              # Example programs
├── docs/                       # Documentation
│   ├── features/              # Feature docs
│   ├── guides/                # User guides
│   └── api/                   # API reference
├── syntaxes/                  # Syntax highlighting
├── zpm_modules/               # Installed packages
└── examples/                  # Example programs

Execution Flow

Source Code (.zx)
       ↓
   [Lexer]  → Tokens
       ↓
   [Parser] → AST
       ↓
  [Evaluator] ←→ [Bytecode Compiler]
       ↓              ↓
 Direct Eval    [VM Execution]
       ↓              ↓
    Result  ←─────────┘

---

📖 Documentation

Complete Documentation

• Ecosystem Strategy - 🌐 Three-phase roadmap for building "anything"
• Feature Guide - Complete feature reference
• Developer Guide - Internal architecture and API
• Documentation Index - All documentation organized
• Quick Start - Getting started tutorial
• Architecture - System design
• Philosophy - Design principles

Keyword & Syntax Documentation

• Keyword Testing Master List - Complete keyword reference with 130+ keywords
• Blockchain Keywords - Smart contract keywords (implements, pure, view, payable, modifier, this, emit)
• Advanced Keywords - Advanced language features
• Modifiers - Function and access modifiers

Language Features by Category

Core Language

• LET - Variable declaration (multiple syntax styles)
• CONST - Constant declaration
• ACTION/FUNCTION/LAMBDA/RETURN - Function definitions
• IF/ELIF/ELSE - Conditional execution
• WHILE/FOR/EACH/IN - Loops and iteration
• BREAK - Loop control - exit loops early
• PRINT/DEBUG - Output and debugging (includes multi-argument print)
• LOG - Output redirection and code generation

Error Handling

• Error Handling - TRY/CATCH/REQUIRE/REVERT
• THROW - Explicit error throwing with custom messages

Object-Oriented & Contracts

• THIS - Current instance reference for contracts and data classes

Module System

• MODULE_SYSTEM - USE, IMPORT, EXPORT, MODULE, PACKAGE
• Main Entry Point - run, execute, is_main patterns

Async & Concurrency

• ASYNC/AWAIT - Asynchronous programming
• ASYNC_CONCURRENCY - Channels, send, receive, atomic

Events & Reactive

• EVENTS_REACTIVE - Event system
• WATCH - Reactive state management

Security Features

• SECURITY - Security features overview
• RESTRICT - Input validation
• SANDBOX - Isolated execution
• AUDIT - Compliance logging
• TRAIL - Event tracking

Performance

• PERFORMANCE - Performance features
• NATIVE - C/C++ FFI
• INLINE - Function inlining
• GC - Garbage collection control
• BUFFER - Memory buffers
• SIMD - SIMD operations

Advanced Features

• DEFER - Deferred cleanup
• PATTERN - Pattern matching
• ENUM - Enumerations
• STREAM - Event streaming

Blockchain & State

• BLOCKCHAIN_STATE - State management

Renderer/UI

• RENDERER_UI - UI and rendering system

Specific Features

• VM Integration - Virtual Machine details
• VM Quick Reference - VM API and usage
• Blockchain - Smart contracts and DApps
• Security - Security features guide
• Concurrency - Async/await and channels
• Module System - Import/export system
• Plugin System - Extending Zexus
• ZPM Guide - Package manager
• Performance - Optimization features

Command Documentation

Each advanced feature has detailed documentation:

• PROTECT - Security policies
• WATCH - Reactive state
• RESTRICT - Input validation
• SANDBOX - Isolated execution
• TRAIL - Audit logging
• DEFER - Deferred execution
• PATTERN - Pattern matching
• And many more in docs/keywords/

---

🤝 Contributing

We welcome contributions! Here's how:

1. Fork the repository
2. Create a feature branch: git checkout -b feature/amazing-feature
3. Commit your changes: git commit -m 'Add amazing feature'
4. Push to the branch: git push origin feature/amazing-feature
5. Open a Pull Request

See CONTRIBUTING.md for detailed guidelines.

---

🧪 Testing

Run Test Suite

# Unit tests
pytest tests/unit/

# Integration tests
cd tests/integration
zx run test_builtins_simple.zx
zx run test_advanced_features_complete.zx

# VM integration tests
python test_vm_integration.py

---

💡 Best Practices

Code Organization

# Use modules for organization
module UserManagement {
    export action createUser(name, email) { ... }
    export action deleteUser(id) { ... }
    
    private action hashPassword(password) { ... }
}

# Import only what you need
use {createUser, deleteUser} from "UserManagement"

Security First

# Always validate inputs
action processPayment(amount, recipient) {
    # Validate amount
    verify amount > 0, "Amount must be positive"
    restrict(amount, {
        type: "integer",
        range: [1, 1000000]
    })
    
    # Validate recipient
    verify is_email(recipient), "Invalid email"
    
    # Sanitize inputs
    let clean_recipient = sanitize(recipient, "email")
    
    # Apply security policies
    protect(processPayment, {
        auth_required: true,
        rate_limit: 10,
        log_access: true
    }, "strict")
}

Error Handling

# Use try-catch for error recovery
try {
    let data = file_read_json("config.json")
    process_config(data)
} catch (error) {
    # Fallback to defaults
    let data = get_default_config()
    debug_log("Using default config", {error: error})
}

# Use defer for cleanup
action process_file(path) {
    let handle = open_file(path)
    defer {
        close_file(handle)  # Always executes
    }
    
    # Process file...
    return result
}

Performance Optimization

# Use native for CPU-intensive tasks
native action calculate_hash(data: string) -> string {
    source: "crypto.cpp"
    function: "sha256_hash"
}

# Mark read-only functions as pure
action pure calculate_total(items) {
    return reduce(items, lambda(sum, item) { sum + item.price }, 0)
}

# Use inline for small frequently-called functions
inline action square(x) {
    return x * x
}

Async Patterns

# Use async/await for I/O operations
async action fetch_user_data(user_id) {
    let profile = await http_get("/users/" + user_id)
    let posts = await http_get("/users/" + user_id + "/posts")
    
    return {profile: profile, posts: posts}
}

# Use channels for producer-consumer patterns
channel<Task> work_queue

action producer() {
    for each task in pending_tasks {
        send(work_queue, task)
    }
    close_channel(work_queue)
}

Testing with Dependency Injection

# Production code
register_dependency("database", ProductionDB())

action saveUser(user) {
    inject database
    database.insert("users", user)
}

# Test code
test_mode(true)
mock_dependency("database", MockDB())
# Now saveUser() uses mocks

Smart Contract Best Practices

# Use modifiers for reusable guards
contract Vault {
    state owner
    
    modifier onlyOwner {
        require(TX.caller == owner, "Not authorized")
    }
    
    action payable withdraw(amount) modifier onlyOwner {
        require(balance >= amount, "Insufficient balance")
        transfer(TX.caller, amount)
        emit Withdrawal(TX.caller, amount)
    }
}

Code Style Guidelines

1. Naming: snake_case for variables/functions, PascalCase for types
2. Indentation: 4 spaces (not tabs)
3. Comments: Use # for single-line comments
4. Functions: Keep under 50 lines when possible
5. Error Messages: Be descriptive and actionable

---

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

---

🙏 Acknowledgments

• Community Contributors - Thank you for your support!
• Open Source Libraries - Built with Python, Click, and Rich
• Inspiration - From modern languages like Rust, Python, Solidity, TypeScript, and Go

---

📞 Contact & Support

• Issues: GitHub Issues
• Discussions: GitHub Discussions
• Email: zaidux@example.com

---

🗺️ Roadmap

Completed ✅

• Core interpreter with hybrid execution
• VM-accelerated bytecode execution with JIT compilation
• 130+ language keywords fully implemented and tested
• Policy-as-code (PROTECT/VERIFY/RESTRICT)
• Enhanced VERIFY with validation builtins (email, URL, phone, patterns)
• Persistent memory management with leak detection
• Dependency injection system with auto-container creation
• Reactive state (WATCH) for automatic change reactions
• Blockchain primitives and smart contracts
• Blockchain modifiers (pure, view, payable, modifier, this, implements, emit)
• Module system (USE, EXPORT, MODULE, PACKAGE) with access control
• Package manager (ZPM) for dependency management
• 100+ built-in functions across all categories
• Advanced types (entities, contracts, protocols, enums, type_alias)
• Security features (sandbox, seal, trail, audit, capability, grant/revoke)
• Concurrency primitives (async/await with Promises, channels, send/receive, atomic)
• Main entry point system (run, execute, is_main, exit_program, on_start/on_exit)
• Enterprise features (middleware, auth, throttle, cache, inject)
• UI rendering system (screen, component, theme, canvas)
• Performance optimization (native, inline, gc, buffer, simd)
• Advanced features (defer, pattern, stream, exactly, embedded)
• Dual-mode DEBUG (function and statement modes)
• Multiple syntax styles (: and = for assignments)
• Tolerance blocks for enhanced REQUIRE
• Comprehensive test suite (1175+ tests)
• World-class error reporting system (v1.5.0)
• Generic types and advanced DATA features (v1.5.0)
• Pattern matching with exhaustiveness checking (v1.5.0)
• Stack trace formatter with source context (v1.5.0)

In Progress 🚧

• VS Code extension with full IntelliSense ✅
• Language Server Protocol (LSP) ✅
• Standard library expansion (fs, http, json, datetime, crypto, blockchain) ✅
• Performance profiling tools ✅
• Debugger integration (DAP) ✅
• Transaction mempool with gas-price ordering ✅ (v1.8.4)
• Gas price oracle (EIP-1559 dynamic base fee) ✅ (v1.8.4)
• Contract ABI encoding ✅ (v1.8.4)
• select statement for channel multiplexing ✅ (v1.8.4)
• Structured concurrency (TaskGroup) ✅ (v1.8.4)
• Backpressure (configurable overflow policy) ✅ (v1.8.4)
• Context propagation (tracing IDs/deadlines) ✅ (v1.8.4)
• use "cache" — LRU + TTL caches ✅ (v1.8.4)
• use "queue" — Message queue abstraction ✅ (v1.8.4)
• use "template" — Server-side rendering ✅ (v1.8.4)
• use "testing" — Assert library + mocking ✅ (v1.8.4)
• use "fuzz" — Coverage-guided fuzzing ✅ (v1.8.4)
• use "secrets" — Vault integration, envelope encryption ✅ (v1.8.4)
• use "netsec" — Port scanner, TLS checker, DNS enum ✅ (v1.8.4)
• use "payloads" — XSS/SQLi/SSRF test vectors ✅ (v1.8.4)
• use "pentest" — Pen-testing framework ✅ (v1.8.4)
• zx audit CLI — SAST scanner with SARIF output ✅ (v1.8.4)
• Contract security analyzer ✅ (v1.8.4)

Planned 🎯

• WASM compilation target
• JIT compilation for hot paths
• Official package registry
• CI/CD templates
• Docker images
• Production monitoring tools

Ecosystem Development 🌐

See Ecosystem Strategy for detailed roadmap.

Phase 1: Build WITH Zexus (Q1-Q2 2025)

• HTTP Server implementation
• PostgreSQL, MySQL, MongoDB drivers
• CLI Framework
• Testing Framework

Phase 2: Integrate INTO Zexus (Q3-Q4 2025)

• HTTP native keywords
• DATABASE native keywords
• AI/ML primitives
• Enhanced GUI keywords

Phase 3: Batteries Included (2026+)

• @zexus/web - Full-stack web framework
• @zexus/db - Database ORM and drivers
• @zexus/ai - Machine learning framework
• @zexus/gui - Cross-platform GUI framework
• Additional official packages

Future Enhancements 🚀

• GPU acceleration for SIMD operations
• Distributed computing primitives
• Native mobile app support
• WebAssembly interop
• Advanced static analysis

---

📊 Project Stats

• Language: Python 3.8+
• Version: 1.8.4 (Stable)
• Lines of Code: ~75,000+
• Keywords: 130+ language keywords
• Built-in Functions: 100+ built-in functions
• Stdlib Modules: 30+
• Test Cases: 2500+ comprehensive tests
• Features: 100+ language features
• Supported Platforms: Linux, macOS, Windows

---

❓ Getting Help & Troubleshooting

Common Issues

"Identifier not found" errors

• Check variable spelling and case sensitivity
• Ensure variable is declared in current or parent scope
• Remember: Zexus uses function-level scoping (not block-level)
• Variables declared in blocks persist in function scope

Import/Module errors

• Use use {symbol} from "module" syntax for imports
• Check that module file exists and has .zx extension
• Ensure exported symbols are marked with export keyword
• Use zpm install to install package dependencies

Syntax errors

• Zexus supports multiple syntax styles: let x = 5 or let x : 5
• Ensure proper braces {} for blocks
• Use ; for statement termination (optional in some contexts)
• Check for unmatched parentheses, brackets, or braces

Performance issues

• Enable VM execution for compute-heavy code (default: auto)
• Use --use-vm flag for explicit VM mode
• Consider using native keyword for C/C++ FFI
• Profile with memory_stats() to check for leaks

PyPI upload fails on Termux with: "unsupported platform tag 'linux_aarch64'"

• PyPI rejects wheels with generic linux_* platform tags (common when building on Termux).
• Fix: upload an sdist (source distribution) and/or a pure-Python wheel:
  • python -m pip install --upgrade build twine
  • python -m build # creates dist/*.tar.gz and (by default) a py3-none-any.whl
  • python -m twine upload dist/*.tar.gz dist/*-py3-none-any.whl
• ZEXUS_BUILD_EXTENSIONS=1 python -m build means: build the optional native extensions (Cython/C/C++) in addition to the Python code (it does not skip Python). This produces a platform-specific wheel.
• If you want “everything compiled” locally, use:
  • ZEXUS_BUILD_EXTENSIONS=1 python -m build
  • or ZEXUS_BUILD_EXTENSIONS=1 python -m pip install .
• For publishing native wheels to PyPI, build them in a manylinux environment (e.g. GitHub Actions + cibuildwheel). Wheels built on Termux are usually not PyPI-uploadable.
  • This repo includes a workflow you can run: .github/workflows/wheels.yml (builds manylinux aarch64 + x86_64, plus macOS/Windows wheels).
  • To publish from GitHub Actions without API tokens, use PyPI Trusted Publishing:
    • PyPI → your project → Settings → Publishing → Trusted publishers → Add a new trusted publisher
    • Provider: GitHub Actions
    • Owner: Zaidux (or your GitHub org/user)
    • Repository: zexus-interpreter
    • Workflow: .github/workflows/wheels.yml
    • Environment: pypi (and optionally also add another trusted publisher entry for testpypi)
    • Then either:
      • Run Actions → “Build wheels (cibuildwheel)” → Run workflow and choose testpypi first, or
      • Push a release tag like v1.7.3 to auto-build + publish

Blockchain/Contract issues

• Remember TX is a global context object (uppercase)
• Use persistent storage for contract state
• Mark value-receiving functions as payable
• Use pure or view for read-only functions

Documentation Quick Links

• Beginner: Start with Quick Start Guide
• Keywords: See Keyword Master List
• Examples: Check examples/ directory
• API Reference: Browse docs/ for detailed docs
• Advanced: Read Advanced Features Guide

Debug Tools

# Enable detailed debugging
debug myVariable;              # Logs with context

# Check execution context
print(is_main())              # Am I the main module?
print(get_module_name())      # Current module name
print(module_info())          # Module metadata

# Memory debugging
track_memory()                # Enable tracking
print(memory_stats())         # Check for leaks

# AST/Token inspection
# Run: zx ast program.zx
# Run: zx tokens program.zx

Getting Support

• GitHub Issues: Report bugs or request features
• Discussions: Ask questions and share ideas
• Documentation: Browse complete docs
• Examples: See working code samples

Community & Ecosystem

Official Resources

• GitHub Repository: Zaidux/zexus-interpreter
• Documentation Site: docs/
• VS Code Extension: .vscode/extensions/zexus-language/
• Syntax Highlighting: syntaxes/

Standard Library Packages

• zexus-blockchain: Blockchain utilities and helpers
• zexus-network: HTTP, WebSocket, and networking
• zexus-math: Advanced mathematical operations
• zexus-stdlib: Standard library modules

Install packages with ZPM:

zpm install zexus-blockchain
zpm install zexus-network
zpm install zexus-math

Learning Resources

• Quick Start: docs/QUICK_START.md
• Examples Directory: examples/
• Test Suite: tests/ - 1175+ working examples
• Keyword Testing: docs/KEYWORD_TESTING_MASTER_LIST.md
• Feature Guides: docs/features/

Development Tools

• CLI: zx for running programs
• Package Manager: zpm for dependencies
• REPL: Interactive shell with zx repl
• AST Inspector: zx ast program.zx
• Token Viewer: zx tokens program.zx
• Validator: zx validate program.zx

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