diff --git a/lark/parser_frontends.py b/lark/parser_frontends.py
index 1356706..b7a3abc 100644
--- a/lark/parser_frontends.py
+++ b/lark/parser_frontends.py
@@ -4,7 +4,6 @@ from .utils import get_regexp_width
 from .parsers.grammar_analysis import GrammarAnalyzer
 from .lexer import Lexer, ContextualLexer, Token
 
-from .common import GrammarError
 from .common import is_terminal, GrammarError
 from .parsers import lalr_parser, earley, xearley, resolve_ambig, cyk
 from .tree import Tree
@@ -138,20 +137,6 @@ class XEarley:
         return self.parser.parse(text)
 
 
-class Earley(WithLexer):
-    def __init__(self, lexer_conf, parser_conf, options=None):
-        self.init_traditional_lexer(lexer_conf)
-
-        self.parser = earley.Parser(parser_conf, self.match,
-                                    resolve_ambiguity=get_ambiguity_resolver(options))
-
-    def match(self, term, token):
-        return term == token.type
-
-    def parse(self, text):
-        tokens = self.lex(text)
-        return self.parser.parse(tokens)
-
 class CYK(WithLexer):
 
   def __init__(self, lexer_conf, parser_conf, options=None):
diff --git a/lark/parsers/cyk.py b/lark/parsers/cyk.py
index fbd52a9..1f9a0fc 100644
--- a/lark/parsers/cyk.py
+++ b/lark/parsers/cyk.py
@@ -1,5 +1,10 @@
 """This module implements a CYK parser."""
 
+# Author: https://github.com/ehudt (2018)
+#
+# Adapted by Erez
+
+
 from collections import defaultdict
 import itertools
 
@@ -140,7 +145,9 @@ class Parser(object):
             else:
                 assert isinstance(child.s, Token)
                 children.append(child.s)
-        return Tree(orig_rule.origin, children, rule=orig_rule)
+        t = Tree(orig_rule.origin, children)
+        t.rule=orig_rule
+        return t
 
 
 def print_parse(node, indent=0):
diff --git a/lark/parsers/earley.py b/lark/parsers/earley.py
index 3586c22..62d3e15 100644
--- a/lark/parsers/earley.py
+++ b/lark/parsers/earley.py
@@ -22,7 +22,8 @@ class Derivation(Tree):
     _hash = None
 
     def __init__(self, rule, items=None):
-        Tree.__init__(self, 'drv', items or [], rule=rule)
+        Tree.__init__(self, 'drv', items or [])
+        self.rule = rule
 
     def _pretty_label(self):    # Nicer pretty for debugging the parser
         return self.rule.origin if self.rule else self.data
diff --git a/lark/tree.py b/lark/tree.py
index 4814b92..a9d4670 100644
--- a/lark/tree.py
+++ b/lark/tree.py
@@ -9,10 +9,9 @@ from .utils import inline_args
 
 ###{standalone
 class Tree(object):
-    def __init__(self, data, children, rule=None):
+    def __init__(self, data, children):
         self.data = data
         self.children = list(children)
-        self.rule = rule
 
     def __repr__(self):
         return 'Tree(%s, %s)' % (self.data, self.children)