Test completion.

IPython/frontend/linefrontendbase.py

@@ -1,277 +1,282 b''
 """
 Base front end class for all line-oriented frontends, rather than
 block-oriented.
 
 Currently this focuses on synchronous frontends.
 """
 __docformat__ = "restructuredtext en"
 
 #-------------------------------------------------------------------------------
 #  Copyright (C) 2008  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-------------------------------------------------------------------------------
 
 #-------------------------------------------------------------------------------
 # Imports
 #-------------------------------------------------------------------------------
 import re
 
 import IPython
 import sys
 
 from frontendbase import FrontEndBase
 from IPython.kernel.core.interpreter import Interpreter
 
 def common_prefix(strings):
     """ Given a list of strings, return the common prefix between all
         these strings.
     """
     ref = strings[0]
     prefix = ''
     for size in range(len(ref)):
         test_prefix = ref[:size+1]
         for string in strings[1:]:
             if not string.startswith(test_prefix):
                 return prefix
         prefix = test_prefix
 
     return prefix
 
 #-------------------------------------------------------------------------------
 # Base class for the line-oriented front ends
 #-------------------------------------------------------------------------------
 class LineFrontEndBase(FrontEndBase):
     """ Concrete implementation of the FrontEndBase class. This is meant
     to be the base class behind all the frontend that are line-oriented,
     rather than block-oriented.
     """
     
     # We need to keep the prompt number, to be able to increment
     # it when there is an exception.
     prompt_number = 1
 
     # We keep a reference to the last result: it helps testing and
     # programatic control of the frontend. 
     last_result = dict(number=0)
 
     # The input buffer being edited
     input_buffer = ''
 
     # Set to true for debug output
     debug = False
 
     #--------------------------------------------------------------------------
     # FrontEndBase interface
     #--------------------------------------------------------------------------
 
     def __init__(self, shell=None, history=None):
         if shell is None:
             shell = Interpreter()
         FrontEndBase.__init__(self, shell=shell, history=history)
         
         self.new_prompt(self.input_prompt_template.substitute(number=1))
 
 
     def complete(self, line):
         """Complete line in engine's user_ns
         
         Parameters
         ----------
         line : string
         
         Result
         ------
         The replacement for the line and the list of possible completions.
         """
         completions = self.shell.complete(line)
         complete_sep =  re.compile('[\s\{\}\[\]\(\)\=]')
         if completions:
             prefix = common_prefix(completions) 
             residual = complete_sep.split(line)[:-1]
             line = line[:-len(residual)] + prefix
         return line, completions 
  
 
     def render_result(self, result):
         """ Frontend-specific rendering of the result of a calculation
         that has been sent to an engine.
         """
         if 'stdout' in result and result['stdout']:
             self.write('\n' + result['stdout'])
         if 'display' in result and result['display']:
             self.write("%s%s\n" % ( 
                             self.output_prompt_template.substitute(
                                     number=result['number']),
                             result['display']['pprint']
                             ) )
        
 
     def render_error(self, failure):
         """ Frontend-specific rendering of error. 
         """
         self.write('\n\n'+str(failure)+'\n\n')
         return failure
 
 
     def is_complete(self, string):
         """ Check if a string forms a complete, executable set of
         commands.
 
         For the line-oriented frontend, multi-line code is not executed
         as soon as it is complete: the users has to enter two line
         returns.
         """
         if string in ('', '\n'):
             # Prefiltering, eg through ipython0, may return an empty
             # string although some operations have been accomplished. We
             # thus want to consider an empty string as a complete
             # statement.
             return True
         elif ( len(self.input_buffer.split('\n'))>2 
                         and not re.findall(r"\n[\t ]*\n[\t ]*$", string)):
             return False
         else:
             # Add line returns here, to make sure that the statement is
             # complete.
             return FrontEndBase.is_complete(self, string.rstrip() + '\n\n')
 
 
     def write(self, string):
         """ Write some characters to the display.
 
             Subclass should overide this method.
         """
         print >>sys.__stderr__, string
 
 
     def execute(self, python_string, raw_string=None):
         """ Stores the raw_string in the history, and sends the
         python string to the interpreter.
         """
         if raw_string is None:
             raw_string = python_string
         # Create a false result, in case there is an exception
         self.last_result = dict(number=self.prompt_number)
         try:
             self.history.input_cache[-1] = raw_string.rstrip()
             result = self.shell.execute(python_string)
             self.last_result = result
             self.render_result(result)
         except:
             self.show_traceback()
         finally:
             self.after_execute()
 
     #--------------------------------------------------------------------------
     # LineFrontEndBase interface
     #--------------------------------------------------------------------------
 
     def prefilter_input(self, string):
         """ Priflter the input to turn it in valid python.
         """
         string = string.replace('\r\n', '\n')
         string = string.replace('\t', 4*' ')
         # Clean the trailing whitespace
         string = '\n'.join(l.rstrip()  for l in string.split('\n'))
         return string
 
 
     def after_execute(self):
         """ All the operations required after an execution to put the
             terminal back in a shape where it is usable.
         """
         self.prompt_number += 1
         self.new_prompt(self.input_prompt_template.substitute(
                             number=(self.last_result['number'] + 1)))
         # Start a new empty history entry
         self._add_history(None, '')
         self.history_cursor = len(self.history.input_cache) - 1
 
 
     def complete_current_input(self):
         """ Do code completion on current line. 
         """
         if self.debug:
             print >>sys.__stdout__, "complete_current_input", 
         line = self.input_buffer
         new_line, completions = self.complete(line)
         if len(completions)>1:
             self.write_completion(completions)
         self.input_buffer = new_line
         if self.debug:
             print >>sys.__stdout__, completions 
 
 
+    def get_line_width(self):
+        """ Return the width of the line in characters.
+        """
+        return 80
+
+
     def write_completion(self, possibilities):
         """ Write the list of possible completions.
         """
         current_buffer = self.input_buffer
         
         self.write('\n')
         max_len = len(max(possibilities, key=len)) + 1
         
-        #now we check how much symbol we can put on a line...
+        # Now we check how much symbol we can put on a line...
         chars_per_line =self.get_line_width()
         symbols_per_line = max(1, chars_per_line/max_len)
 
         pos = 1
         buf = []
         for symbol in possibilities:
             if pos < symbols_per_line:
                 buf.append(symbol.ljust(max_len))
                 pos += 1
             else:
                 buf.append(symbol.rstrip() + '\n')
                 pos = 1
         self.write(''.join(buf))
         self.new_prompt(self.input_prompt_template.substitute(
                             number=self.last_result['number'] + 1))
         self.input_buffer = current_buffer
 
 
-
     def new_prompt(self, prompt):
         """ Prints a prompt and starts a new editing buffer. 
 
             Subclasses should use this method to make sure that the
             terminal is put in a state favorable for a new line
             input.
         """
         self.input_buffer = ''
         self.write(prompt)
 
 
     #--------------------------------------------------------------------------
     # Private API
     #--------------------------------------------------------------------------
  
     def _on_enter(self):
         """ Called when the return key is pressed in a line editing
             buffer.
         """
         current_buffer = self.input_buffer
         cleaned_buffer = self.prefilter_input(current_buffer)
         if self.is_complete(cleaned_buffer):
             self.execute(cleaned_buffer, raw_string=current_buffer)
         else:
             self.input_buffer += self._get_indent_string(
                                                 current_buffer[:-1])
             if current_buffer[:-1].split('\n')[-1].rstrip().endswith(':'):
                 self.input_buffer += '\t'
 
 
     def _get_indent_string(self, string):
         """ Return the string of whitespace that prefixes a line. Used to
         add the right amount of indendation when creating a new line.
         """
         string = string.replace('\t', ' '*4)
         string = string.split('\n')[-1]
         indent_chars = len(string) - len(string.lstrip())
         indent_string = '\t'*(indent_chars // 4) + \
                             ' '*(indent_chars % 4)
 
         return indent_string
  
     

IPython/frontend/tests/test_prefilterfrontend.py

@@ -1,125 +1,129 b''
 # encoding: utf-8
 """
 Test process execution and IO redirection.
 """
 
 __docformat__ = "restructuredtext en"
 
 #-------------------------------------------------------------------------------
 #  Copyright (C) 2008  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is
 #  in the file COPYING, distributed as part of this software.
 #-------------------------------------------------------------------------------
 
 from IPython.frontend.prefilterfrontend import PrefilterFrontEnd
 from cStringIO import StringIO
 import string
 
 class TestPrefilterFrontEnd(PrefilterFrontEnd):
     
     input_prompt_template = string.Template('')
     output_prompt_template = string.Template('')
 
     def __init__(self):
         self.out = StringIO()
         PrefilterFrontEnd.__init__(self)
 
     def write(self, string):
        self.out.write(string) 
 
     def _on_enter(self):
         self.input_buffer += '\n'
         PrefilterFrontEnd._on_enter(self)
 
 
 def test_execution():
     """ Test execution of a command.
     """
     f = TestPrefilterFrontEnd()
     f.input_buffer = 'print 1\n'
     f._on_enter()
     assert f.out.getvalue() == '1\n'
 
 
 def test_multiline():
     """ Test execution of a multiline command.
     """
     f = TestPrefilterFrontEnd()
     f.input_buffer = 'if True:'
     f._on_enter()
     f.input_buffer += 'print 1'
     f._on_enter()
     assert f.out.getvalue() == ''
     f._on_enter()
     assert f.out.getvalue() == '1\n'
     f = TestPrefilterFrontEnd()
     f.input_buffer='(1 +'
     f._on_enter()
     f.input_buffer += '0)'
     f._on_enter()
     assert f.out.getvalue() == ''
     f._on_enter()
     assert f.out.getvalue() == '1\n'
 
 
 def test_capture():
     """ Test the capture of output in different channels.
     """
     # Test on the OS-level stdout, stderr.
     f = TestPrefilterFrontEnd()
     f.input_buffer = \
             'import os; out=os.fdopen(1, "w"); out.write("1") ; out.flush()'
     f._on_enter()
     assert f.out.getvalue() == '1'
     f = TestPrefilterFrontEnd()
     f.input_buffer = \
             'import os; out=os.fdopen(2, "w"); out.write("1") ; out.flush()'
     f._on_enter()
     assert f.out.getvalue() == '1'
 
      
 def test_magic():
     """ Test the magic expansion and history.
     
         This test is fairly fragile and will break when magics change.
     """
     f = TestPrefilterFrontEnd()
     f.input_buffer += '%who\n'
     f._on_enter()
     assert f.out.getvalue() == 'Interactive namespace is empty.\n'
 
 
 def test_help():
     """ Test object inspection.
     """
     f = TestPrefilterFrontEnd()
     f.input_buffer += "def f():"
     f._on_enter()
     f.input_buffer += "'foobar'"
     f._on_enter()
     f.input_buffer += "pass"
     f._on_enter()
     f._on_enter()
     f.input_buffer += "f?"
     f._on_enter()
     assert f.out.getvalue().split()[-1] == 'foobar' 
 
 
 def test_completion():
     """ Test command-line completion.
     """
     f = TestPrefilterFrontEnd()
     f.input_buffer = 'zzza = 1'
     f._on_enter()
     f.input_buffer = 'zzzb = 2'
     f._on_enter()
     f.input_buffer = 'zz'
+    f.complete_current_input()
+    assert f.out.getvalue() == '\nzzza zzzb '
+    assert f.input_buffer == 'zzz'
 
 
 if __name__ == '__main__':
     test_magic()
     test_help()
     test_execution()
     test_multiline()
     test_capture()
+    test_completion()