Improve match_examples() for Earley (Issue #760)

lark/parsers/earley.py

@@ -245,7 +245,7 @@ class Parser:
 
             if not next_set and not next_to_scan:
                 expect = {i.expect.name for i in to_scan}
-                raise UnexpectedToken(token, expect, considered_rules=set(to_scan), state=frozenset(i.expect for i in to_scan))
+                raise UnexpectedToken(token, expect, considered_rules=set(to_scan), state=frozenset(i.s for i in to_scan))
 
             return next_to_scan
 
@@ -303,7 +303,7 @@ class Parser:
         solutions = [n.node for n in columns[-1] if n.is_complete and n.node is not None and n.s == start_symbol and n.start == 0]
         if not solutions:
             expected_terminals = [t.expect for t in to_scan]
-            raise UnexpectedEOF(expected_terminals, state=frozenset(i.expect for i in to_scan))
+            raise UnexpectedEOF(expected_terminals, state=frozenset(i.s for i in to_scan))
 
         if self.debug:
             from .earley_forest import ForestToPyDotVisitor

lark/parsers/xearley.py

@@ -114,7 +114,7 @@ class Parser(BaseParser):
 
             if not next_set and not delayed_matches and not next_to_scan:
                 raise UnexpectedCharacters(stream, i, text_line, text_column, {item.expect.name for item in to_scan},
-                                           set(to_scan), state=frozenset(i.expect for i in to_scan))
+                                           set(to_scan), state=frozenset(i.s for i in to_scan))
 
             return next_to_scan
 

tests/test_parser.py

@@ -2355,7 +2355,7 @@ def _make_parser_test(LEXER, PARSER):
                     return u.match_examples(p.parse, {
                         0: ['abe'],
                         1: ['ab'],
-                        2: ['cbc'],
+                        2: ['cbc', 'dbc'],
                     })
                 assert False
 
@@ -2364,6 +2364,7 @@ def _make_parser_test(LEXER, PARSER):
             assert match_error("bbc") == 2
             assert match_error("cbc") == 2
             self.assertEqual( match_error("dbc"), 2 )
+            self.assertEqual( match_error("ebc"), 2 )
 
 
         @unittest.skipIf(not regex or sys.version_info[0] == 2, 'Unicode and Python 2 do not place nicely together.')