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API Reference
=============
Lark
----
.. autoclass:: lark.Lark
:members: open, parse, parse_interactive, lex, save, load, get_terminal, open_from_package
Using Unicode character classes with ``regex``
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Python's builtin ``re`` module has a few persistent known bugs and also won't parse
advanced regex features such as character classes.
With ``pip install lark[regex]``, the ``regex`` module will be
installed alongside lark and can act as a drop-in replacement to ``re``.
Any instance of Lark instantiated with ``regex=True`` will use the ``regex`` module instead of ``re``.
For example, we can use character classes to match PEP-3131 compliant Python identifiers:
::
from lark import Lark
>>> g = Lark(r"""
?start: NAME
NAME: ID_START ID_CONTINUE*
ID_START: /[\p{Lu}\p{Ll}\p{Lt}\p{Lm}\p{Lo}\p{Nl}_]+/
ID_CONTINUE: ID_START | /[\p{Mn}\p{Mc}\p{Nd}\p{Pc}·]+/
""", regex=True)
>>> g.parse('வணக்கம்')
'வணக்கம்'
Tree
----
.. autoclass:: lark.Tree
:members: pretty, find_pred, find_data, iter_subtrees, scan_values,
iter_subtrees_topdown, __rich__
Token
-----
.. autoclass:: lark.Token
Transformer, Visitor & Interpreter
----------------------------------
See :doc:`visitors`.
ForestVisitor, ForestTransformer, & TreeForestTransformer
-----------------------------------------------------------
See :doc:`forest`.
UnexpectedInput
---------------
.. autoclass:: lark.exceptions.UnexpectedInput
:members: get_context, match_examples
.. autoclass:: lark.exceptions.UnexpectedToken
.. autoclass:: lark.exceptions.UnexpectedCharacters
.. autoclass:: lark.exceptions.UnexpectedEOF
InteractiveParser
-----------------
.. autoclass:: lark.parsers.lalr_interactive_parser.InteractiveParser
:members: choices, feed_token, copy, pretty, resume_parse, exhaust_lexer, accepts, as_immutable
.. autoclass:: lark.parsers.lalr_interactive_parser.ImmutableInteractiveParser
:members: choices, feed_token, copy, pretty, resume_parse, exhaust_lexer, accepts, as_mutable
ast_utils
---------
For an example of using ``ast_utils``, see `/examples/advanced/create_ast.py`_
.. autoclass:: lark.ast_utils.Ast
.. autoclass:: lark.ast_utils.AsList
.. autofunction:: lark.ast_utils.create_transformer
.. _/examples/advanced/create_ast.py: examples/advanced/create_ast.html
Indenter
--------
.. autoclass:: lark.indenter.Indenter
.. autoclass:: lark.indenter.PythonIndenter
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