tree-sitter-kotlin

Common errors

• AttributeError: type object 'Language' has no attribute 'build_library'

  cause Attempting to use the `build_library` method on `tree_sitter.Language`, which was removed in recent versions of the `tree_sitter` Python binding.
  fix Remove calls to `Language.build_library()`. For official grammars like Kotlin, install them directly via pip (e.g., `pip install tree-sitter-kotlin`). For custom grammars, manage compilation externally.

• ModuleNotFoundError: No module named 'tree_sitter_kotlin'

  cause The `tree-sitter-kotlin` package has not been installed or is not accessible in the current Python environment.
  fix Install the package using pip: `pip install tree-sitter-kotlin`.

• ValueError: Invalid language name or path for Language('/tmp/my_grammar.so', 'kotlin')

  cause The path to the compiled grammar (`.so` or `.dll` file) is incorrect, or the language name provided does not match the compiled grammar's identifier. For pip-installed grammars, direct file paths are usually not used.
  fix Ensure that the grammar is loaded correctly via the package's `language()` function, e.g., `KOTLIN_LANGUAGE = Language(tree_sitter_kotlin.language())`, rather than attempting to load a `.so` file directly if using the pip-installed package.

Warnings

• breaking The `Language.build_library()` static method for compiling grammars was removed from the `tree_sitter` Python binding around versions 0.21.x/0.22. Direct compilation of local grammar sources is no longer supported via this API.
  Fix: Instead of `Language.build_library()`, install pre-compiled language packages (e.g., `pip install tree-sitter-kotlin`). For custom grammars, external compilation tools or older `tree_sitter` versions (pre-0.22.0) are required.
• gotcha Tree-sitter can fail to parse large files (e.g., >32KB) with a generic 'Invalid argument' error if the internal buffer size is not adequately configured.
  Fix: When creating a `Parser`, consider setting a larger `bufferSize` in the `parse()` method's options if dealing with very large source files, or splitting files into smaller chunks before parsing. Consult `tree_sitter` documentation for `parse()` method options.
• gotcha Grammar objects are loaded via a function call, not directly as attributes. For `tree-sitter-kotlin`, you must call `tskt.language()` to get the underlying C grammar object.
  Fix: Ensure you call `tree_sitter_kotlin.language()` (e.g., `Language(tskt.language())`) and do not treat `language` as a direct attribute or constant without the `()`.

Install

• pip install tree-sitter-kotlin Install with pip

Imports

• language
  wrong:

  from tree_sitter_kotlin import KOTLIN_LANGUAGE

  correct:

  import tree_sitter_kotlin as tskt
  from tree_sitter import Language
  KOTLIN_LANGUAGE = Language(tskt.language())

  The grammar object is exposed via a `language()` method within the `tree_sitter_kotlin` module, which should then be passed to `tree_sitter.Language`.

Quickstart

Demonstrates how to load the `tree-sitter-kotlin` grammar and use `tree_sitter.Parser` to parse a basic Kotlin code snippet, then access the root node of the generated Abstract Syntax Tree.

import tree_sitter_kotlin as tskt
from tree_sitter import Language, Parser

# Load the Kotlin grammar
KOTLIN_LANGUAGE = Language(tskt.language())

# Create a parser and set the language
parser = Parser()
parser.set_language(KOTLIN_LANGUAGE)

# Sample Kotlin code to parse
kotlin_code = b'''
fun main() {
    val greeting = "Hello, Tree-sitter!"
    println(greeting)
}
'''

# Parse the code
tree = parser.parse(kotlin_code)

# Get the root node of the AST
root_node = tree.root_node

print(f"Root node type: {root_node.type}")
print(f"Root node children count: {len(root_node.children)}")
# Example: Find a function declaration
function_node = root_node.children[0] # Assuming 'fun main()' is the first child
if function_node.type == 'function_declaration':
    print(f"Found function: {function_node.text.decode('utf8').split('(')[0]}")