Tython - A Typed Python Transpiler

Tython is a transpiler that converts type-annotated Python-like code to standard Python with type hints.

• Static type checking
• Python type hints generation
• Function declarations with type annotations
• Variable declarations with type inference
• String concatenation and arithmetic operations
• Comparison operators
• Single-line and multi-line comments
• Configurable output formatting
• Docstring generation

• str: String type
• int: Integer type
• float: Float type
• bool: Boolean type

tython -input file.ty [options]

• -input string: Input Tython file (required)
• -output string: Output Python file (default: input filename with .py extension)
• -no-type-hints: Disable type hints in output
• -python-version string: Target Python version (default: "3.8")
• -indent-size int: Number of spaces for indentation (default: 4)
• -docstrings: Add docstrings to functions
• -debug: Enable debug output

Input file (example.ty):

# Variable declarations
name: str = "John"
age: int = 25

/* Function with type annotations */
def calculate_bmi(weight: float, height: float) -> float {
    bmi: float = weight / (height * height)
}

Generated output:

#!/usr/bin/env python3.8
name = "John"  # type: str
age = 25  # type: int

def calculate_bmi(weight: float, height: float) -> float:
    """
    Input parameters:
        weight: float
        height: float
    Returns: float
    """
    bmi = weight / (height * height)  # type: float
    return bmi

• cmd/tython/main.go: Command-line interface and program entry point
• pkg/: Core packages
  • lexer/: Tokenizes the input code
  • parser/: Parses tokens into an AST
  • typechecker/: Performs static type checking
  • codegen/: Generates Python code with type hints

1. Adding a New Type:

   • Add the type in parser/parser.go under the Type constants
   • Update type checking rules in typechecker/typechecker.go
   • Add default value in codegen/codegen.go

2. Adding New Operators:

   • Add token in lexer/lexer.go
   • Update operator handling in parser/parser.go
   • Add type checking rules in typechecker/typechecker.go

3. Adding New Statements:

   • Define new statement type in parser/parser.go
   • Add parsing logic in parser.go
   • Implement type checking in typechecker.go
   • Add code generation in codegen.go

• Go 1.24.2 or higher

go build -o tython.exe ./cmd/tython