|
|
"""
|
|
|
Base front end class for all line-oriented frontends, rather than
|
|
|
block-oriented.
|
|
|
|
|
|
Currently this focuses on synchronous frontends.
|
|
|
"""
|
|
|
__docformat__ = "restructuredtext en"
|
|
|
|
|
|
#-------------------------------------------------------------------------------
|
|
|
# Copyright (C) 2008-2011 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 sys
|
|
|
import codeop
|
|
|
|
|
|
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 last prompt displayed. Useful for continuation prompts.
|
|
|
last_prompt = ''
|
|
|
|
|
|
# The input buffer being edited
|
|
|
input_buffer = ''
|
|
|
|
|
|
# Set to true for debug output
|
|
|
debug = False
|
|
|
|
|
|
# A banner to print at startup
|
|
|
banner = None
|
|
|
|
|
|
#--------------------------------------------------------------------------
|
|
|
# FrontEndBase interface
|
|
|
#--------------------------------------------------------------------------
|
|
|
|
|
|
def __init__(self, shell=None, history=None, banner=None, *args, **kwargs):
|
|
|
if shell is None:
|
|
|
shell = Interpreter()
|
|
|
FrontEndBase.__init__(self, shell=shell, history=history)
|
|
|
|
|
|
if banner is not None:
|
|
|
self.banner = banner
|
|
|
|
|
|
def start(self):
|
|
|
""" Put the frontend in a state where it is ready for user
|
|
|
interaction.
|
|
|
"""
|
|
|
if self.banner is not None:
|
|
|
self.write(self.banner, refresh=False)
|
|
|
|
|
|
self.new_prompt(self.input_prompt_template.substitute(number=1))
|
|
|
|
|
|
|
|
|
def complete(self, line):
|
|
|
"""Complete line in engine's user_ns
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
line : string
|
|
|
|
|
|
Returns
|
|
|
-------
|
|
|
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:
|
|
|
self.capture_output()
|
|
|
try:
|
|
|
# Add line returns here, to make sure that the statement is
|
|
|
# complete (except if '\' was used).
|
|
|
# This should probably be done in a different place (like
|
|
|
# maybe 'prefilter_input' method? For now, this works.
|
|
|
clean_string = string.rstrip('\n')
|
|
|
if not clean_string.endswith('\\'): clean_string +='\n\n'
|
|
|
is_complete = codeop.compile_command(clean_string,
|
|
|
"<string>", "exec")
|
|
|
self.release_output()
|
|
|
except Exception as e:
|
|
|
# XXX: Hack: return True so that the
|
|
|
# code gets executed and the error captured.
|
|
|
is_complete = True
|
|
|
return is_complete
|
|
|
|
|
|
|
|
|
def write(self, string, refresh=True):
|
|
|
""" Write some characters to the display.
|
|
|
|
|
|
Subclass should overide this method.
|
|
|
|
|
|
The refresh keyword argument is used in frontends with an
|
|
|
event loop, to choose whether the write should trigget an UI
|
|
|
refresh, and thus be syncrhonous, or not.
|
|
|
"""
|
|
|
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:
|
|
|
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):
|
|
|
""" Prefilter 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, new_line=new_line)
|
|
|
elif not line == new_line:
|
|
|
self.input_buffer = new_line
|
|
|
if self.debug:
|
|
|
print >>sys.__stdout__, 'line', line
|
|
|
print >>sys.__stdout__, 'new_line', new_line
|
|
|
print >>sys.__stdout__, completions
|
|
|
|
|
|
|
|
|
def get_line_width(self):
|
|
|
""" Return the width of the line in characters.
|
|
|
"""
|
|
|
return 80
|
|
|
|
|
|
|
|
|
def write_completion(self, possibilities, new_line=None):
|
|
|
""" Write the list of possible completions.
|
|
|
|
|
|
new_line is the completed input line that should be displayed
|
|
|
after the completion are writen. If None, the input_buffer
|
|
|
before the completion is used.
|
|
|
"""
|
|
|
if new_line is None:
|
|
|
new_line = 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...
|
|
|
chars_per_line = self.get_line_width()
|
|
|
symbols_per_line = max(1, chars_per_line/max_len)
|
|
|
|
|
|
pos = 1
|
|
|
completion_string = []
|
|
|
for symbol in possibilities:
|
|
|
if pos < symbols_per_line:
|
|
|
completion_string.append(symbol.ljust(max_len))
|
|
|
pos += 1
|
|
|
else:
|
|
|
completion_string.append(symbol.rstrip() + '\n')
|
|
|
pos = 1
|
|
|
self.write(''.join(completion_string))
|
|
|
self.new_prompt(self.input_prompt_template.substitute(
|
|
|
number=self.last_result['number'] + 1))
|
|
|
self.input_buffer = new_line
|
|
|
|
|
|
|
|
|
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)
|
|
|
|
|
|
|
|
|
def continuation_prompt(self):
|
|
|
"""Returns the current continuation prompt.
|
|
|
"""
|
|
|
return ("."*(len(self.last_prompt)-2) + ': ')
|
|
|
|
|
|
|
|
|
def execute_command(self, command, hidden=False):
|
|
|
""" Execute a command, not only in the model, but also in the
|
|
|
view, if any.
|
|
|
"""
|
|
|
return self.shell.execute(command)
|
|
|
|
|
|
#--------------------------------------------------------------------------
|
|
|
# Private API
|
|
|
#--------------------------------------------------------------------------
|
|
|
|
|
|
def _on_enter(self, new_line_pos=0):
|
|
|
""" Called when the return key is pressed in a line editing
|
|
|
buffer.
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
new_line_pos : integer, optional
|
|
|
Position of the new line to add, starting from the
|
|
|
end (0 adds a new line after the last line, -1 before
|
|
|
the last line...)
|
|
|
|
|
|
Returns
|
|
|
-------
|
|
|
True if execution is triggered
|
|
|
"""
|
|
|
current_buffer = self.input_buffer
|
|
|
# XXX: This string replace is ugly, but there should be no way it
|
|
|
# fails.
|
|
|
prompt_less_buffer = re.sub('^' + self.continuation_prompt(),
|
|
|
'', current_buffer).replace('\n' + self.continuation_prompt(),
|
|
|
'\n')
|
|
|
cleaned_buffer = self.prefilter_input(prompt_less_buffer)
|
|
|
if self.is_complete(cleaned_buffer):
|
|
|
self.execute(cleaned_buffer, raw_string=current_buffer)
|
|
|
return True
|
|
|
else:
|
|
|
# Start a new line.
|
|
|
new_line_pos = -new_line_pos
|
|
|
lines = current_buffer.split('\n')[:-1]
|
|
|
prompt_less_lines = prompt_less_buffer.split('\n')
|
|
|
# Create the new line, with the continuation prompt, and the
|
|
|
# same amount of indent than the line above it.
|
|
|
new_line = self.continuation_prompt() + \
|
|
|
self._get_indent_string('\n'.join(
|
|
|
prompt_less_lines[:new_line_pos-1]))
|
|
|
if len(lines) == 1:
|
|
|
# We are starting a first continuation line. Indent it.
|
|
|
new_line += '\t'
|
|
|
elif current_buffer[:-1].split('\n')[-1].rstrip().endswith(':'):
|
|
|
# The last line ends with ":", autoindent the new line.
|
|
|
new_line += '\t'
|
|
|
|
|
|
if new_line_pos == 0:
|
|
|
lines.append(new_line)
|
|
|
else:
|
|
|
lines.insert(new_line_pos, new_line)
|
|
|
self.input_buffer = '\n'.join(lines)
|
|
|
|
|
|
|
|
|
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
|
|
|
|
|
|
|
|
|
|
