Cypy

A Python-like language that compiles to Cython.

Features

• Python Compatibility: Partial Python syntax compatibility
• Gradual Typing: Annotated variables use static types, unannotated fall back to object
• Compile-time Checking: cypyc transpiler catches type errors early
• Cython Backend: Compiles to Cython for high-performance C code
• Modern Syntax: Pattern matching, enum, struct, trait, let/var, and more
• Concurrency: go keyword for coroutines, spawn for threads
• Pipe Operator: |> for function chaining
• List Comprehensions: Full support with nested loops and conditions

Quick Start

# Install dependencies
pip install -e .

# Transpile a Cypy file
cypyc input.cypy

# Transpile and compile
cypyc --compile input.cypy

# Type check only
cypyc --check input.cypy

Syntax Examples

Structs

struct Point:
    x: float
    y: float
    
    def distance(self, other: Point) -> float:
        return ((self.x - other.x) ** 2 + (self.y - other.y) ** 2) ** 0.5

Pattern Matching

match value:
    case 1:
        return "one"
    case (a, b):
        return f"tuple: {a}, {b}"
    case _:
        return "other"

Enum

enum Color:
    Red
    Green
    Blue

def process_color(c: Color) -> int:
    match c:
        case Color.Red:
            return 1
        case _:
            return 0

Let/Var Variables

let x: int = 10  # Immutable, cannot be reassigned
var y: int = 20  # Mutable, can be reassigned

Pipe Operator

let result = 5 |> double |> square  # equivalent to square(double(5))

Go (Coroutines) and Spawn (Threads)

let task = go fetch_data(url)  # asyncio.create_task
let thread = spawn heavy_computation()  # threading.Thread

List Comprehensions

let squares = [x ** 2 for x in range(10) if x % 2 == 0]

Documentation

• SYNTAX_IMPLEMENTATION_STATUS.md - 语法实现状态报告
• SYNTAX/00-introduction.md - 语言介绍
• SYNTAX/01-basic-types.md - 基础类型
• SYNTAX/02-type-annotations.md - 类型注解
• SYNTAX/05-struct.md - 结构体
• SYNTAX/06-enum.md - 枚举
• SYNTAX/07-trait-impl.md - 特质系统
• SYNTAX/09-functions.md - 函数
• SYNTAX/10-variables.md - 变量
• SYNTAX/20-concurrency.md - 并发
• SYNTAX/23-compilation.md - 编译系统

Project-Level Compilation

# Build entire project with cross-module type inference
cypyc build <project_directory>

# Build with specific entry point
cypyc build <project_directory> --entry main

# Type check only
cypyc build <project_directory> --check-only

Examples

Explore the examples/ directory for code examples:

• basic_types.cypy - Basic types and type conversion
• control_flow.cypy - Control flow statements
• functions.cypy - Functions and pipe operator
• struct_enum.cypy - Structs and enums
• concurrency.cypy - Coroutines and threads
• list_comprehension.cypy - List comprehensions

Testing

python scripts/run_tests.py

License

MIT