Source Code for Module lepl.lexer.lines._test.left_bug

  1   
  2  # The contents of this file are subject to the Mozilla Public License 
  3  # (MPL) Version 1.1 (the "License"); you may not use this file except 
  4  # in compliance with the License. You may obtain a copy of the License 
  5  # at http://www.mozilla.org/MPL/ 
  6  # 
  7  # Software distributed under the License is distributed on an "AS IS" 
  8  # basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See 
  9  # the License for the specific language governing rights and 
 10  # limitations under the License. 
 11  # 
 12  # The Original Code is LEPL (http://www.acooke.org/lepl) 
 13  # The Initial Developer of the Original Code is Andrew Cooke. 
 14  # Portions created by the Initial Developer are Copyright (C) 2009-2010 
 15  # Andrew Cooke (andrew@acooke.org). All Rights Reserved. 
 16  # 
 17  # Alternatively, the contents of this file may be used under the terms 
 18  # of the LGPL license (the GNU Lesser General Public License, 
 19  # http://www.gnu.org/licenses/lgpl.html), in which case the provisions 
 20  # of the LGPL License are applicable instead of those above. 
 21  # 
 22  # If you wish to allow use of your version of this file only under the 
 23  # terms of the LGPL License and not to allow others to use your version 
 24  # of this file under the MPL, indicate your decision by deleting the 
 25  # provisions above and replace them with the notice and other provisions 
 26  # required by the LGPL License.  If you do not delete the provisions 
 27  # above, a recipient may use your version of this file under either the 
 28  # MPL or the LGPL License. 
 29   
 30  ''' 
 31  See http://groups.google.com/group/lepl/browse_thread/thread/79e39e03a03718cc?hl=en_US 
 32   
 33  The different tree structures seen here seem to be related to the how the 
 34  left-recursive memoisation fails.  In the case without lexer the string is 
 35  shorter, which causes failure earlier.  I am not at all sure about this... 
 36  ''' 
 37   
 38  from unittest import TestCase 
 39  from logging import basicConfig, DEBUG 
 40   
 41  from lepl import * 
 42  from lepl._test.base import assert_str 
 43   
 44   
 45 -class LeftBugTest(TestCase): 
 46       
 47 -    def test_right_no_lexer(self): 
 48          #basicConfig(level=DEBUG) 
 49          word = Any() 
 50          expr1 = Delayed() 
 51          call = (expr1 & word) > List 
 52          expr1 += (call | Empty() | word) 
 53          program = expr1 & Eos() 
 54          program.config.trace_stack().auto_memoize() 
 55          parser = program.get_parse() 
 56          print(parser.matcher.tree()) 
 57          parsed = parser("abc") 
 58          assert_str(parsed[0], 
 59  """List 
 60   +- List 
 61   |   +- List 
 62   |   |   `- 'a' 
 63   |   `- 'b' 
 64   `- 'c'""") 
 65       
 66 -    def test_right(self): 
 67          #basicConfig(level=DEBUG) 
 68          #CLine = ContinuedBLineFactory(Token(r'\\')) 
 69          word = Token("[A-Za-z_][A-Za-z0-9_]*") 
 70          expr1 = Delayed() 
 71          call = (expr1 & word) > List 
 72          expr1 += (call | Empty() | word) 
 73          program = Trace(expr1 & Eos()) 
 74          program.config.trace_stack().auto_memoize() 
 75          parser = program.get_parse() 
 76          #print(parser.matcher.tree()) 
 77          parsed = parser("a b c") 
 78          assert_str(parsed[0], 
 79  """List 
 80   +- List 
 81   |   +- List 
 82   |   |   `- 'a' 
 83   |   `- 'b' 
 84   `- 'c'""") 
 85   
 86 -    def test_left(self): 
 87          CLine = ContinuedLineFactory(r'\\') 
 88          expr0 = Token("[A-Za-z_][A-Za-z0-9_]*") 
 89          expr1 = Delayed() 
 90          call = (expr1 & expr0) > List # Deliberately not expr0 & expr1 
 91          expr1 += (call | Empty () | expr0) 
 92          program = (CLine(expr1) & Eos()) 
 93          program.config.lines(block_policy=explicit).auto_memoize() 
 94          parsed = program.parse("a b c") 
 95          assert_str(parsed[0], 
 96  """List 
 97   +- List 
 98   |   +- List 
 99   |   |   `- 'a' 
100   |   `- 'b' 
101   `- 'c'""") 
102