Oops, had commited leaving some merge junk behind.

IPython/frontend/frontendbase.py

@@ -1,422 +1,359 b''
 # encoding: utf-8
 # -*- test-case-name: IPython.frontend.tests.test_frontendbase -*-
 """
 frontendbase provides an interface and base class for GUI frontends for 
 IPython.kernel/IPython.kernel.core.
 
 Frontend implementations will likely want to subclass FrontEndBase. 
 
 Author: Barry Wark
 """
 __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 string
 import uuid
 import _ast
 
 from zopeinterface import Interface, Attribute, implements, classProvides
 
 from IPython.kernel.core.history import FrontEndHistory
 from IPython.kernel.core.util import Bunch
 from IPython.kernel.engineservice import IEngineCore
 
 ##############################################################################
 # TEMPORARY!!! fake configuration, while we decide whether to use tconfig or
 # not
 
 rc = Bunch()
 rc.prompt_in1 = r'In [$number]:  '
 rc.prompt_in2 = r'...'
 rc.prompt_out = r'Out [$number]:  '
 
 ##############################################################################
 # Interface definitions
 ##############################################################################
 
 class IFrontEndFactory(Interface):
     """Factory interface for frontends."""
     
     def __call__(engine=None, history=None):
         """
         Parameters:
         interpreter : IPython.kernel.engineservice.IEngineCore
         """
         
         pass
 
 
 class IFrontEnd(Interface):
     """Interface for frontends. All methods return t.i.d.Deferred"""
     
     Attribute("input_prompt_template", "string.Template instance\
                 substituteable with execute result.")
     Attribute("output_prompt_template", "string.Template instance\
                 substituteable with execute result.")
     Attribute("continuation_prompt_template", "string.Template instance\
                 substituteable with execute result.")
     
     def update_cell_prompt(result, blockID=None):
         """Subclass may override to update the input prompt for a block. 
 
         In asynchronous frontends, this method will be called as a
         twisted.internet.defer.Deferred's callback/errback.
         Implementations should thus return result when finished.
         
         Result is a result dict in case of success, and a
         twisted.python.util.failure.Failure in case of an error
         """
         
         pass
     
     def render_result(result):
         """Render the result of an execute call. Implementors may choose the
          method of rendering.
         For example, a notebook-style frontend might render a Chaco plot 
         inline.
         
         Parameters:
             result : dict (result of IEngineBase.execute )
                 blockID = result['blockID']
         
         Result:
             Output of frontend rendering
         """
         
         pass
     
     def render_error(failure):
         """Subclasses must override to render the failure. 
         
         In asynchronous frontend, since this method will be called as a
         twisted.internet.defer.Deferred's callback. Implementations
         should thus return result when finished.
         
         blockID = failure.blockID
         """
         
         pass
     
     def input_prompt(number=''):
         """Returns the input prompt by subsituting into 
         self.input_prompt_template
         """
         pass
     
     def output_prompt(number=''):
         """Returns the output prompt by subsituting into 
         self.output_prompt_template
         """
         
         pass
     
     def continuation_prompt():
         """Returns the continuation prompt by subsituting into 
         self.continuation_prompt_template
         """
         
         pass
     
     def is_complete(block):
         """Returns True if block is complete, False otherwise."""
         
         pass
     
     def compile_ast(block):
         """Compiles block to an _ast.AST"""
         
         pass
     
     def get_history_previous(current_block):
         """Returns the block previous in  the history. Saves currentBlock if
         the history_cursor is currently at the end of the input history"""
         pass
     
     def get_history_next():
         """Returns the next block in the history."""
         
         pass
     
     def complete(self, line):
         """Returns the list of possible completions, and the completed
             line.
 
         The input argument is the full line to be completed. This method
         returns both the line completed as much as possible, and the list
         of further possible completions (full words).
         """
         pass
 
 
 ##############################################################################
 # Base class for all the frontends. 
 ##############################################################################
 
 class FrontEndBase(object):
     """
     FrontEndBase manages the state tasks for a CLI frontend:
         - Input and output history management
         - Input/continuation and output prompt generation
         
     Some issues (due to possibly unavailable engine):
         - How do we get the current cell number for the engine?
         - How do we handle completions?
     """
     
     history_cursor = 0
     
     input_prompt_template = string.Template(rc.prompt_in1)
     output_prompt_template = string.Template(rc.prompt_out)
     continuation_prompt_template = string.Template(rc.prompt_in2)
     
     def __init__(self, shell=None, history=None):
         self.shell = shell
         if history is None:
                 self.history = FrontEndHistory(input_cache=[''])
         else:
             self.history = history
         
     
     def input_prompt(self, number=''):
         """Returns the current input prompt
         
         It would be great to use ipython1.core.prompts.Prompt1 here
         """
         return self.input_prompt_template.safe_substitute({'number':number})
     
     
     def continuation_prompt(self):
         """Returns the current continuation prompt"""
         
         return self.continuation_prompt_template.safe_substitute()
     
     def output_prompt(self, number=''):
         """Returns the output prompt for result"""
         
         return self.output_prompt_template.safe_substitute({'number':number})
     
     
     def is_complete(self, block):
         """Determine if block is complete.
         
         Parameters
         block : string
         
         Result 
         True if block can be sent to the engine without compile errors.
         False otherwise.
         """
         
         try:
             ast = self.compile_ast(block)
         except:
             return False
         
         lines = block.split('\n')
         return (len(lines)==1 or str(lines[-1])=='')
     
     
     def compile_ast(self, block):
         """Compile block to an AST
         
         Parameters:
             block : str
         
         Result:
             AST
         
         Throws:
             Exception if block cannot be compiled
         """
         
         return compile(block, "<string>", "exec", _ast.PyCF_ONLY_AST)
     
     
     def execute(self, block, blockID=None):
         """Execute the block and return the result.
         
         Parameters:
             block : {str, AST}
             blockID : any
                 Caller may provide an ID to identify this block. 
                 result['blockID'] := blockID
         
         Result:
             Deferred result of self.interpreter.execute
         """
         
         if(not self.is_complete(block)):
             raise Exception("Block is not compilable")
         
         if(blockID == None):
             blockID = uuid.uuid4() #random UUID
         
         try:
             result = self.shell.execute(block)
         except Exception,e:
             e = self._add_block_id_for_failure(e, blockID=blockID)
             e = self.update_cell_prompt(e, blockID=blockID)
             e = self.render_error(e)
         else:
             result = self._add_block_id_for_result(result, blockID=blockID)
             result = self.update_cell_prompt(result, blockID=blockID)
             result = self.render_result(result)
         
         return result
     
     
     def _add_block_id_for_result(self, result, blockID):
         """Add the blockID to result or failure. Unfortunatley, we have to 
         treat failures differently than result dicts.
         """
         
         result['blockID'] = blockID
         
         return result
     
     def _add_block_id_for_failure(self, failure, blockID):
         """_add_block_id_for_failure"""
         failure.blockID = blockID
         return failure
     
     
     def _add_history(self, result, block=None):
         """Add block to the history"""
         
         assert(block != None)
         self.history.add_items([block])
         self.history_cursor += 1
         
         return result
     
     
     def get_history_previous(self, current_block):
         """ Returns previous history string and decrement history cursor.
         """
         command = self.history.get_history_item(self.history_cursor - 1)
         
         if command is not None:
             if(self.history_cursor+1 == len(self.history.input_cache)):
                 self.history.input_cache[self.history_cursor] = current_block
             self.history_cursor -= 1
         return command
     
     
     def get_history_next(self):
         """ Returns next history string and increment history cursor.
         """
         command = self.history.get_history_item(self.history_cursor+1)
         
         if command is not None:
             self.history_cursor += 1
         return command
     
     ###
     # Subclasses probably want to override these methods...
     ###
     
     def update_cell_prompt(self, result, blockID=None):
         """Subclass may override to update the input prompt for a block. 
 
         This method only really makes sens in asyncrhonous frontend.
         Since this method will be called as a 
         twisted.internet.defer.Deferred's callback, implementations should 
         return result when finished.
         """
         
         raise NotImplementedError
     
     
     def render_result(self, result):
         """Subclasses must override to render result. 
         
         In asynchronous frontends, this method will be called as a
         twisted.internet.defer.Deferred's callback. Implementations
         should thus return result when finished.
         """
         
         raise NotImplementedError
     
     
     def render_error(self, failure):
-<<<<<<< TREE
         """Subclasses must override to render the failure. 
         
         In asynchronous frontends, this method will be called as a
         twisted.internet.defer.Deferred's callback. Implementations
         should thus return result when finished.
         """
         
         raise NotImplementedError
-    
-
-
-=======
-        """Subclasses must override to render the failure. Since this method 
-        will be called as a twisted.internet.defer.Deferred's callback, 
-        implementations should return result when finished.
-        """
-        
-        return failure
-    
-
-
-class AsyncFrontEndBase(FrontEndBase):
-    """
-    Overrides FrontEndBase to wrap execute in a deferred result.
-    All callbacks are made as callbacks on the deferred result.
-    """
-    
-    implements(IFrontEnd)
-    classProvides(IFrontEndFactory)
-    
-    def __init__(self, engine=None, history=None):
-        assert(engine==None or IEngineCore.providedBy(engine))
-        self.engine = IEngineCore(engine)
-        if history is None:
-                self.history = FrontEndHistory(input_cache=[''])
-        else:
-            self.history = history
-    
-    
-    def execute(self, block, blockID=None):
-        """Execute the block and return the deferred result.
-        
-        Parameters:
-            block : {str, AST}
-            blockID : any
-                Caller may provide an ID to identify this block. 
-                result['blockID'] := blockID
-        
-        Result:
-            Deferred result of self.interpreter.execute
-        """
-        
-        if(not self.is_complete(block)):
-            from twisted.python.failure import Failure
-            return Failure(Exception("Block is not compilable"))
-        
-        if(blockID == None):
-            blockID = uuid.uuid4() #random UUID
-        
-        d = self.engine.execute(block)
-        d.addCallback(self._add_history, block=block)
-        d.addCallback(self._add_block_id_for_result, blockID)
-        d.addErrback(self._add_block_id_for_failure, blockID)
-        d.addBoth(self.update_cell_prompt, blockID=blockID)
-        d.addCallbacks(self.render_result, 
-            errback=self.render_error)
-        
-        return d
-    
->>>>>>> MERGE-SOURCE