from langkit.dsl import ASTNode, abstract, Field
from langkit.parsers import Grammar, List, Pick, Or, Opt, Null
from language.lexer import *

@abstract
class TestNode(ASTNode):
    pass

@abstract
class NamedEntity (TestNode):
    name = Field()

class Entity(NamedEntity):
    nested = Field()

class Call(NamedEntity):
    args = Field()
    nested = Field()

class Identifier(TestNode):
    token_node = True

class Number(TestNode):
    token_node = True   

test_grammar = Grammar('main_rule')
G = test_grammar

test_grammar.add_rules(
    main_rule=G.entity_list,
    entity_list=List (Or (G.call, G.entity, G.number), sep=',', empty_valid=True),
    entity=Entity (G.identifier, Opt ('{', G.entity_list, '}')),
    call=Call (G.identifier, '(', G.entity_list, ')', Opt ('{', G.entity_list, '}')),
    identifier=Identifier(Token.Identifier),
    number=Number(Token.Integer)
)