Language Support

Graph-sitter provides first-class support for both Python and TypeScript codebases. The language is automatically inferred when you initialize a codebase.

Language Detection

When you create a new Codebase instance, Graph-sitter automatically detects the programming language:

from graph_sitter import Codebase

# Automatically detects Python or TypeScript
codebase = Codebase("./")

# View language with `codebase.language`
print(codebase.language)  # "python" or "typescript"

Learn more about codebase initialization options in Parsing Codebases.

Type System

Graph-sitter uses specialized types for each language. These are defined as type aliases:

# Python codebases use PyCodebaseType
PyCodebaseType = Codebase[
    PyFile, Directory, PySymbol, PyClass, PyFunction,
    PyImport, PyAssignment, Interface, TypeAlias,
    PyParameter, PyCodeBlock
]

# TypeScript codebases use TSCodebaseType
TSCodebaseType = Codebase[
    TSFile, Directory, TSSymbol, TSClass, TSFunction,
    TSImport, TSAssignment, TSInterface, TSTypeAlias,
    TSParameter, TSCodeBlock
]

Every code element has both a Python and TypeScript implementation that inherits from a common base class. For example:

• Function
  • PyFunction
  • TSFunction
• Class
  • PyClass
  • TSClass
• Import
  • PyImport
  • TSImport

…

# Base class (core/function.py)
class Function:
    """Abstract representation of a Function."""
    pass

# Python implementation (python/function.py)
class PyFunction(Function):
    """Extends Function for Python codebases."""
    pass

# TypeScript implementation (typescript/function.py)
class TSFunction(Function):
    """Extends Function for TypeScript codebases."""
    pass

This inheritance pattern means that most Graph-sitter programs can work with either Python or TypeScript without modification, since they share the same API structure.

# Works for both Python and TypeScript
for function in codebase.functions:
    print(f"Function: {function.name}")
    print(f"Parameters: {[p.name for p in function.parameters]}")
    print(f"Return type: {function.return_type}")

TypeScript-Specific Features

Some features are only available in TypeScript codebases:

• Types and Interfaces: TypeScript’s rich type system (TSTypeAlias, TSInterface)
• Exports: Module exports and re-exports (TSExport)
• JSX/TSX: React component handling (see React and JSX)

Example of TypeScript-specific features:

# Only works with TypeScript codebases
if isinstance(codebase, TSCodebaseType):
    # Work with TypeScript interfaces
    for interface in codebase.interfaces:
        print(f"Interface: {interface.name}")
        print(f"Extends: {[i.name for i in interface.parent_interfaces]}")

    # Work with type aliases
    for type_alias in codebase.type_aliases:
        print(f"Type alias: {type_alias.name}")