Source code for opengrammar.parser

"""
The parser module contains the parser for the Meta Syntax and the Universal Grammar.
"""

from pathlib import Path

import rich
from lark import Lark

from opengrammar.parser.meta_syntax import MetaSyntaxAST
from opengrammar.parser.transformer import MetaSyntaxTransformer

# Load Meta Syntax
meta_syntax_path = Path(__file__).parent / "meta_syntax.lark"
with open(meta_syntax_path, "r") as _ms:
    _meta_syntax = _ms.read()




class MetaSyntaxParser:
    """
    Parses Meta Syntax into an AST.
    """

    def __init__(self) -> None:
        """
        Initializes the MetaSyntaxParser.
        """
        self._lark_parser: Lark = Lark(
            grammar=_meta_syntax, start="syntax", parser="earley", ambiguity="explicit"
        )



    def parse(self, text: str) -> MetaSyntaxAST:
        """
        Parses the text into an AST.

        :param text: A string with valid Meta Syntax.
        :return: A Meta Syntax AST.
        """
        _grammar_tree = self._lark_parser.parse(text)
        _grammar_transformer = MetaSyntaxTransformer()
        _grammar_ast = _grammar_transformer.transform(_grammar_tree)
        return _grammar_ast






class UniversalParser:
    """
    Parses a Universal Grammar into an AST.
    """

    def __init__(self, grammar: str):
        """
        Initializes the UniversalParser.

        :param grammar: A valid Universal Grammar string.
        """
        self.grammar: str = grammar

        meta_syntax_parser: MetaSyntaxParser = MetaSyntaxParser()
        self.meta_ast = meta_syntax_parser.parse(text=self.grammar)



if __name__ == "__main__":
    with open("grammar.ug", "r") as f:
        sample_grammar = f.read()

    up = UniversalParser(grammar=sample_grammar)
    rich.print(up.meta_ast)