import py

from rpython.rlib.parsing.tree import Nonterminal, Symbol
from rpython.rlib.parsing.lexer import Token, SourcePos

class TestTreeAppLevel(object):

    def test_nonterminal_simple(self):
        pos = SourcePos(1,2,3)
        tree = Nonterminal(symbol="a",
            children=[
                Symbol(symbol="b",
                    additional_info="b",
                    token=Token(name="B",
                        source="b",
                        source_pos=pos))])
        assert tree.getsourcepos() == pos

    def test_nonterminal_nested(self):
        pos = SourcePos(1,2,3)
        tree = Nonterminal(symbol="a",
            children=[
                Nonterminal(symbol="c",
                    children=[
                       Symbol(symbol="b",
                            additional_info="b",
                            token=Token(name="B",
                                source="b",
                                source_pos=pos))])])
        assert tree.getsourcepos() == pos

    def test_nonterminal_simple_empty(self):
        tree = Nonterminal(symbol="a",
            children=[])
        assert len(tree.children) == 0 # trivial
        py.test.raises(IndexError, tree.getsourcepos)

    def test_nonterminal_nested_empty(self):
        tree = Nonterminal(symbol="a",
            children=[Nonterminal(symbol="c",
            children=[Nonterminal(symbol="c",
            children=[Nonterminal(symbol="c",
            children=[Nonterminal(symbol="c",
            children=[Nonterminal(symbol="c",
            children=[Nonterminal(symbol="c",
            children=[])])])])])])])
        assert len(tree.children) != 0 # the not-so-trivial part.
        py.test.raises(IndexError, tree.getsourcepos)

class TestTreeTranslated(object):
    def compile(self, f):
        from rpython.translator.c.test.test_genc import compile
        return compile(f, [])

    def test_nonterminal_simple_empty(self):
        def foo():
            tree = Nonterminal(symbol="a",
                children=[])
            try:
                return tree.getsourcepos()
            except IndexError:
                return -42
        f = self.compile(foo)
        assert f() == -42

    def test_nonterminal_nested_empty(self):
        def foo():
            tree = Nonterminal(symbol="a",
                children=[Nonterminal(symbol="c",
                children=[Nonterminal(symbol="c",
                children=[Nonterminal(symbol="c",
                children=[Nonterminal(symbol="c",
                children=[Nonterminal(symbol="c",
                children=[Nonterminal(symbol="c",
                children=[])])])])])])])
            try:
                return tree.getsourcepos()
            except IndexError:
                return -42
        f = self.compile(foo)
        assert f() == -42