Cleaner newline handling.

IPython/frontend/linefrontendbase.py

@@ -1,179 +1,177 b''
 """
 Base front end class for all line-oriented frontends.
 
 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
 
 
 from frontendbase import FrontEndBase
 from IPython.kernel.core.interpreter import Interpreter
 
 
 def common_prefix(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):
     
     # We need to keep the prompt number, to be able to increment
     # it when there is an exception.
     prompt_number = 1
 
     # To bootstrap
     last_result = dict(number=0)
 
     #--------------------------------------------------------------------------
     # Public API
     #--------------------------------------------------------------------------
 
     def __init__(self, shell=None, history=None):
         if shell is None:
             shell = Interpreter()
         FrontEndBase.__init__(self, shell=shell, history=history)
         
         #FIXME: print banner.
         banner = """IPython1 %s -- An enhanced Interactive Python.""" \
                             % IPython.__version__
 
 
     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):
         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 % result['number'],
                             result['display']['pprint']
                             ) )
        
 
     def render_error(self, failure):
         self.insert_text('\n\n'+str(failure)+'\n\n')
         return failure
 
 
     def prefilter_input(self, string):
         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 is_complete(self, string):
         if string in ('', '\n'):
             return True
         elif ( len(self.get_current_edit_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 execute(self, python_string, raw_string=None):
         """ Send the python_string to the interpreter, stores the
             raw_string in the history and starts a new prompt.
         """
         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()
 
 
     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.prompt % (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 _on_enter(self):
         """ Called when the return key is pressed in a line editing
             buffer.
         """
         current_buffer = self.get_current_edit_buffer()
         cleaned_buffer = self.prefilter_input(current_buffer)
         if self.is_complete(cleaned_buffer):
             self.execute(cleaned_buffer, raw_string=current_buffer)
         else:
-            if len(current_buffer.split('\n'))>2:
-                # We need to clean the trailing '\n'
-                self.write(self._get_indent_string(current_buffer[:-1]))
-            else:
+            self.write(self._get_indent_string(current_buffer[:-1]))
+            if current_buffer.rstrip().endswith(':'):
                 self.write('\t')
 
 
     #--------------------------------------------------------------------------
     # Private API
     #--------------------------------------------------------------------------
  
     def _get_indent_string(self, string):
         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