# The MIT License

#

# Copyright (c) 2009-2011 the bpython authors.

#

# Permission is hereby granted, free of charge, to any person obtaining a copy

# of this software and associated documentation files (the "Software"), to deal

# in the Software without restriction, including without limitation the rights

# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

# copies of the Software, and to permit persons to whom the Software is

# furnished to do so, subject to the following conditions:

#

# The above copyright notice and this permission notice shall be included in

# all copies or substantial portions of the Software.

#

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

# THE SOFTWARE.

#

from __future__ import with_statement

import code

import codecs

import errno

import inspect

import logging

import os

import pydoc

import shlex

import subprocess

import sys

import tempfile

import textwrap

import traceback

import unicodedata

from itertools import takewhile

from locale import getpreferredencoding

from socket import error as SocketError

from string import Template

from urllib import quote as urlquote

from urlparse import urlparse

from xmlrpclib import ServerProxy, Error as XMLRPCError

from pygments.token import Token

from bpython import inspection

from bpython._py3compat import PythonLexer, py3

from bpython.formatter import Parenthesis

from bpython.translations import _

import bpython.autocomplete as autocomplete

class Interpreter(code.InteractiveInterpreter):

def __init__(self, locals=None, encoding=None):

"""The syntaxerror callback can be set at any time and will be called

on a caught syntax error. The purpose for this in bpython is so that

the repl can be instantiated after the interpreter (which it

necessarily must be with the current factoring) and then an exception

callback can be added to the Interpeter instance afterwards - more

specifically, this is so that autoindentation does not occur after a

traceback."""

self.encoding = encoding or sys.getdefaultencoding()

self.syntaxerror_callback = None

# Unfortunately code.InteractiveInterpreter is a classic class, so no super()

code.InteractiveInterpreter.__init__(self, locals)

if not py3:

def runsource(self, source, filename='<input>', symbol='single',

encode=True):

if encode:

source = '# coding: %s\n%s' % (self.encoding,

source.encode(self.encoding))

return code.InteractiveInterpreter.runsource(self, source,

filename, symbol)

def showsyntaxerror(self, filename=None):

"""Override the regular handler, the code's copied and pasted from

code.py, as per showtraceback, but with the syntaxerror callback called

and the text in a pretty colour."""

if self.syntaxerror_callback is not None:

self.syntaxerror_callback()

type, value, sys.last_traceback = sys.exc_info()

sys.last_type = type

sys.last_value = value

if filename and type is SyntaxError:

# Work hard to stuff the correct filename in the exception

try:

msg, (dummy_filename, lineno, offset, line) = value.args

except:

# Not the format we expect; leave it alone

pass

else:

# Stuff in the right filename and right lineno

if not py3:

lineno -= 1

value = SyntaxError(msg, (filename, lineno, offset, line))

sys.last_value = value

list = traceback.format_exception_only(type, value)

self.writetb(list)

def showtraceback(self):

"""This needs to override the default traceback thing

so it can put it into a pretty colour and maybe other

stuff, I don't know"""

try:

t, v, tb = sys.exc_info()

sys.last_type = t

sys.last_value = v

sys.last_traceback = tb

tblist = traceback.extract_tb(tb)

del tblist[:1]

# Set the right lineno (encoding header adds an extra line)

if not py3:

for i, (filename, lineno, module, something) in enumerate(tblist):

if filename == '<input>':

tblist[i] = (filename, lineno - 1, module, something)

l = traceback.format_list(tblist)

if l:

l.insert(0, "Traceback (most recent call last):\n")

l[len(l):] = traceback.format_exception_only(t, v)

finally:

tblist = tb = None

self.writetb(l)

def writetb(self, lines):

"""This outputs the traceback and should be overridden for anything

fancy."""

for line in lines:

self.write(line)

class History(object):

"""Stores readline-style history and current place in it"""

def __init__(self, entries=None, duplicates=False):

if entries is None:

self.entries = ['']

else:

self.entries = list(entries)

self.index = 0 # how many lines back in history is currently selected

# where 0 is the saved typed line, 1 the prev entered line

self.saved_line = '' # what was on the prompt before using history

self.duplicates = duplicates

def append(self, line):

line = line.rstrip('\n')

if line:

if not self.duplicates:

# remove duplicates

try:

while True:

self.entries.remove(line)

except ValueError:

pass

self.entries.append(line)

def first(self):

"""Move back to the beginning of the history."""

if not self.is_at_end:

self.index = len(self.entries)

return self.entries[-self.index]

def back(self, start=True, search=False, target=None, include_current=False):

"""Move one step back in the history."""

if target is None:

target = self.saved_line

if not self.is_at_end:

if search:

self.index += self.find_partial_match_backward(target, include_current)

elif start:

self.index += self.find_match_backward(target, include_current)

else:

self.index += 1

return self.entry

@property

def entry(self):

"""The current entry, which may be the saved line"""

return self.entries[-self.index] if self.index else self.saved_line

@property

def entries_by_index(self):

return list(reversed(self.entries + [self.saved_line]))

def find_match_backward(self, search_term, include_current=False):

for idx, val in enumerate(self.entries_by_index[self.index + (0 if include_current else 1):]):

if val.startswith(search_term):

return idx + (0 if include_current else 1)

return 0

def find_partial_match_backward(self, search_term, include_current=False):

for idx, val in enumerate(self.entries_by_index[self.index + (0 if include_current else 1):]):

if search_term in val:

return idx + (0 if include_current else 1)

return 0

def forward(self, start=True, search=False, target=None, include_current=False):

"""Move one step forward in the history."""

if target is None:

target = self.saved_line

if self.index > 1:

if search:

self.index -= self.find_partial_match_forward(target, include_current)

elif start:

self.index -= self.find_match_forward(target, include_current)

else:

self.index -= 1

return self.entry

else:

self.index = 0

return self.saved_line

def find_match_forward(self, search_term, include_current=False):

#TODO these are no longer efficient, because we realize the whole list. Does this matter?

for idx, val in enumerate(reversed(self.entries_by_index[:max(0, self.index - (1 if include_current else 0))])):

if val.startswith(search_term):

return idx + (0 if include_current else 1)

return self.index

def find_partial_match_forward(self, search_term, include_current=False):

for idx, val in enumerate(reversed(self.entries_by_index[:max(0, self.index - (1 if include_current else 0))])):

if search_term in val:

return idx + (0 if include_current else 1)

return self.index

def last(self):

"""Move forward to the end of the history."""

if not self.is_at_start:

self.index = 0

return self.entries[0]

@property

def is_at_end(self):

return self.index >= len(self.entries) or self.index == -1

@property

def is_at_start(self):

return self.index == 0

def enter(self, line):

if self.index == 0:

self.saved_line = line

@classmethod

def from_filename(cls, filename):

history = cls()

history.load(filename)

return history

def load(self, filename, encoding):

with codecs.open(filename, 'r', encoding, 'ignore') as hfile:

for line in hfile:

self.append(line)

def reset(self):

self.index = 0

self.saved_line = ''

def save(self, filename, encoding, lines=0):

with codecs.open(filename, 'w', encoding, 'ignore') as hfile:

for line in self.entries[-lines:]:

hfile.write(line)

hfile.write('\n')

class MatchesIterator(object):

"""Stores a list of matches and which one is currently selected if any.

Also responsible for doing the actual replacement of the original line with

the selected match.

A MatchesIterator can be `clear`ed to reset match iteration, and

`update`ed to set what matches will be iterated over."""

def __init__(self):

self.current_word = '' # word being replaced in the original line of text

self.matches = None # possible replacements for current_word

self.index = -1 # which word is currently replacing the current word

self.orig_cursor_offset = None # cursor position in the original line

self.orig_line = None # original line (before match replacements)

self.completer = None # class describing the current type of completion

def __nonzero__(self):

"""MatchesIterator is False when word hasn't been replaced yet"""

return self.index != -1

def __iter__(self):

return self

def current(self):

if self.index == -1:

raise ValueError('No current match.')

return self.matches[self.index]

def next(self):

self.index = (self.index + 1) % len(self.matches)

return self.matches[self.index]

def previous(self):

if self.index <= 0:

self.index = len(self.matches)

self.index -= 1

return self.matches[self.index]

def cur_line(self):

"""Returns a cursor offset and line with the current substitution made"""

return self.substitute(self.current())

def substitute(self, match):

"""Returns a cursor offset and line with match substituted in"""

start, end, word = self.completer.locate(self.orig_cursor_offset, self.orig_line)

result = start + len(match), self.orig_line[:start] + match + self.orig_line[end:]

return result

def is_cseq(self):

return bool(os.path.commonprefix(self.matches)[len(self.current_word):])

def substitute_cseq(self):

"""Returns a new line by substituting a common sequence in, and update matches"""

cseq = os.path.commonprefix(self.matches)

new_cursor_offset, new_line = self.substitute(cseq)

if len(self.matches) == 1:

self.clear()

else:

self.update(new_cursor_offset, new_line, self.matches, self.completer)

if len(self.matches) == 1:

self.clear()

return new_cursor_offset, new_line

def update(self, cursor_offset, current_line, matches, completer):

"""Called to reset the match index and update the word being replaced

Should only be called if there's a target to update - otherwise, call clear"""

self.orig_cursor_offset = cursor_offset

self.orig_line = current_line

assert matches is not None

self.matches = matches

self.completer = completer

#assert self.completer.locate(self.orig_cursor_offset, self.orig_line) is not None, (self.completer.locate, self.orig_cursor_offset, self.orig_line)

self.index = -1

self.start, self.end, self.current_word = self.completer.locate(self.orig_cursor_offset, self.orig_line)

def clear(self):

self.matches = []

self.cursor_offset = -1

self.current_line = ''

self.current_word = ''

self.start = None

self.end = None

self.index = -1

class Interaction(object):

def __init__(self, config, statusbar=None):

self.config = config

if statusbar:

self.statusbar = statusbar

def confirm(self, s):

raise NotImplementedError

def notify(self, s, n=10):

raise NotImplementedError

def file_prompt(self, s):

raise NotImplementedError

class Repl(object):

"""Implements the necessary guff for a Python-repl-alike interface

The execution of the code entered and all that stuff was taken from the

Python code module, I had to copy it instead of inheriting it, I can't

remember why. The rest of the stuff is basically what makes it fancy.

It reads what you type, passes it to a lexer and highlighter which

returns a formatted string. This then gets passed to echo() which

parses that string and prints to the curses screen in appropriate

colours and/or bold attribute.

The Repl class also keeps two stacks of lines that the user has typed in:

One to be used for the undo feature. I am not happy with the way this

works. The only way I have been able to think of is to keep the code

that's been typed in in memory and re-evaluate it in its entirety for each

"undo" operation. Obviously this means some operations could be extremely

slow. I'm not even by any means certain that this truly represents a

genuine "undo" implementation, but it does seem to be generally pretty

effective.

If anyone has any suggestions for how this could be improved, I'd be happy

to hear them and implement it/accept a patch. I researched a bit into the

idea of keeping the entire Python state in memory, but this really seems

very difficult (I believe it may actually be impossible to work) and has

its own problems too.

The other stack is for keeping a history for pressing the up/down keys

to go back and forth between lines.

XXX Subclasses should implement echo, current_line, cw

"""

def __init__(self, interp, config):

"""Initialise the repl.

interp is a Python code.InteractiveInterpreter instance

config is a populated bpython.config.Struct.

"""

self.config = config

self.cut_buffer = ''

self.buffer = []

self.interp = interp

self.interp.syntaxerror_callback = self.clear_current_line

self.match = False

self.rl_history = History(duplicates=config.hist_duplicates)

self.s_hist = []

self.history = []

self.evaluating = False

self.matches_iter = MatchesIterator()

self.argspec = None

self.current_func = None

self.highlighted_paren = None

self._C = {}

self.prev_block_finished = 0

self.interact = Interaction(self.config)

# previous pastebin content to prevent duplicate pastes, filled on call

# to repl.pastebin

self.prev_pastebin_content = ''

self.prev_pastebin_url = ''

# Necessary to fix mercurial.ui.ui expecting sys.stderr to have this

# attribute

self.closed = False

pythonhist = os.path.expanduser(self.config.hist_file)

if os.path.exists(pythonhist):

self.rl_history.load(pythonhist,

getpreferredencoding() or "ascii")

@property

def ps1(self):

try:

return str(sys.ps1)

except AttributeError:

return '>>> '

@property

def ps2(self):

try:

return str(sys.ps2)

except AttributeError:

return '... '

def startup(self):

"""

Execute PYTHONSTARTUP file if it exits. Call this after front

end-specific initialisation.

"""

filename = os.environ.get('PYTHONSTARTUP')

if filename and os.path.isfile(filename):

with open(filename, 'r') as f:

if py3:

self.interp.runsource(f.read(), filename, 'exec')

else:

self.interp.runsource(f.read(), filename, 'exec', encode=False)

def current_string(self, concatenate=False):

"""If the line ends in a string get it, otherwise return ''"""

tokens = self.tokenize(self.current_line)

string_tokens = list(takewhile(token_is_any_of([Token.String,

Token.Text]),

reversed(tokens)))

if not string_tokens:

return ''

opening = string_tokens.pop()[1]

string = list()

for (token, value) in reversed(string_tokens):

if token is Token.Text:

continue

elif opening is None:

opening = value

elif token is Token.String.Doc:

string.append(value[3:-3])

opening = None

elif value == opening:

opening = None

if not concatenate:

string = list()

else:

string.append(value)

if opening is None:

return ''

return ''.join(string)

def get_object(self, name):

attributes = name.split('.')

obj = eval(attributes.pop(0), self.interp.locals)

while attributes:

with inspection.AttrCleaner(obj):

obj = getattr(obj, attributes.pop(0))

return obj

def get_args(self):

"""Check if an unclosed parenthesis exists, then attempt to get the

argspec() for it. On success, update self.argspec and return True,

otherwise set self.argspec to None and return False"""

self.current_func = None

if not self.config.arg_spec:

return False

# Get the name of the current function and where we are in

# the arguments

stack = [['', 0, '']]

try:

for (token, value) in PythonLexer().get_tokens(

self.current_line):

if token is Token.Punctuation:

if value in '([{':

stack.append(['', 0, value])

elif value in ')]}':

stack.pop()

elif value == ',':

try:

stack[-1][1] += 1

except TypeError:

stack[-1][1] = ''

stack[-1][0] = ''

elif value == ':' and stack[-1][2] == 'lambda':

stack.pop()

else:

stack[-1][0] = ''

elif (token is Token.Name or token in Token.Name.subtypes or

token is Token.Operator and value == '.'):

stack[-1][0] += value

elif token is Token.Operator and value == '=':

stack[-1][1] = stack[-1][0]

stack[-1][0] = ''

elif token is Token.Keyword and value == 'lambda':

stack.append(['', 0, value])

else:

stack[-1][0] = ''

while stack[-1][2] in '[{':

stack.pop()

_, arg_number, _ = stack.pop()

func, _, _ = stack.pop()

except IndexError:

return False

if not func:

return False

try:

f = self.get_object(func)

except Exception:

# another case of needing to catch every kind of error

# since user code is run in the case of descriptors

# XXX: Make sure you raise here if you're debugging the completion

# stuff !

return False

if inspect.isclass(f):

try:

if f.__init__ is not object.__init__:

f = f.__init__

except AttributeError:

return None

self.current_func = f

self.argspec = inspection.getargspec(func, f)

if self.argspec:

self.argspec.append(arg_number)

return True

return False

def get_source_of_current_name(self):

"""Return the source code of the object which is bound to the

current name in the current input line. Return `None` if the

source cannot be found."""

try:

obj = self.current_func

if obj is None:

line = self.current_line

if inspection.is_eval_safe_name(line):

obj = self.get_object(line)

if obj is None:

return None

source = inspect.getsource(obj)

except (AttributeError, IOError, NameError, TypeError):

return None

else:

return source

def set_docstring(self):

self.docstring = None

if not self.get_args():

self.argspec = None

elif self.current_func is not None:

try:

self.docstring = pydoc.getdoc(self.current_func)

except IndexError:

self.docstring = None

else:

# pydoc.getdoc() returns an empty string if no

# docstring was found

if not self.docstring:

self.docstring = None

def complete(self, tab=False):

"""Construct a full list of possible completions and construct and

display them in a window. Also check if there's an available argspec

(via the inspect module) and bang that on top of the completions too.

The return value is whether the list_win is visible or not.

If no matches are found, just return whether there's an argspec to show

If any matches are found, save them and select the first one.

If tab is True exactly one match found, make the replacement and return

the result of running complete() again on the new line.

"""

self.set_docstring()

matches, completer = autocomplete.get_completer(

self.cursor_offset,

self.current_line,

self.interp.locals,

self.argspec,

'\n'.join(self.buffer + [self.current_line]),

self.config.autocomplete_mode if hasattr(self.config, 'autocomplete_mode') else autocomplete.SIMPLE,

self.config.complete_magic_methods)

#TODO implement completer.shown_before_tab == False (filenames shouldn't fill screen)

if (matches is None # no completion is relevant

or len(matches) == 0): # a target for completion was found

# but no matches were found

self.matches_iter.clear()

return bool(self.argspec)

self.matches_iter.update(self.cursor_offset,

self.current_line, matches, completer)

if len(matches) == 1:

self.matches_iter.next()

if tab: # if this complete is being run for a tab key press, tab() to do the swap

self.cursor_offset, self.current_line = self.matches_iter.substitute_cseq()

return Repl.complete(self)

elif self.matches_iter.current_word == matches[0]:

self.matches_iter.clear()

return False

return completer.shown_before_tab

else:

assert len(matches) > 1

return tab or completer.shown_before_tab

def format_docstring(self, docstring, width, height):

"""Take a string and try to format it into a sane list of strings to be

put into the suggestion box."""

lines = docstring.split('\n')

out = []

i = 0

for line in lines:

i += 1

if not line.strip():

out.append('\n')

for block in textwrap.wrap(line, width):

out.append(' ' + block + '\n')

if i >= height:

return out

i += 1

# Drop the last newline

out[-1] = out[-1].rstrip()

return out

def next_indentation(self):

"""Return the indentation of the next line based on the current

input buffer."""

if self.buffer:

indentation = next_indentation(self.buffer[-1],

self.config.tab_length)

if indentation and self.config.dedent_after > 0:

line_is_empty = lambda line: not line.strip()

empty_lines = takewhile(line_is_empty, reversed(self.buffer))

if sum(1 for _ in empty_lines) >= self.config.dedent_after:

indentation -= 1

else:

indentation = 0

return indentation

def formatforfile(self, s):

"""Format the stdout buffer to something suitable for writing to disk,

i.e. without >>> and ... at input lines and with "# OUT: " prepended to

output lines."""

def process():

for line in s.split('\n'):

if line.startswith(self.ps1):

yield line[len(self.ps1):]

elif line.startswith(self.ps2):

yield line[len(self.ps2):]

elif line.rstrip():

yield "# OUT: %s" % (line,)

return "\n".join(process())

def write2file(self):

"""Prompt for a filename and write the current contents of the stdout

buffer to disk."""

try:

fn = self.interact.file_prompt('Save to file (Esc to cancel): ')

if not fn:

self.interact.notify("Save cancelled.")

return

except ValueError:

self.interact.notify("Save cancelled.")

return

if fn.startswith('~'):

fn = os.path.expanduser(fn)

if not fn.endswith('.py') and self.config.save_append_py:

fn = fn + '.py'

mode = 'w'

if os.path.exists(fn):

mode = self.interact.file_prompt('%s already exists. Do you want '

'to (c)ancel, (o)verwrite or '

'(a)ppend? ' % (fn, ))

if mode in ('o', 'overwrite'):

mode = 'w'

elif mode in ('a', 'append'):

mode = 'a'

else:

self.interact.notify('Save cancelled.')

return

s = self.formatforfile(self.getstdout())

try:

f = open(fn, mode)

f.write(s)

f.close()

except IOError:

self.interact.notify("Disk write error for file '%s'." % (fn, ))

else:

self.interact.notify('Saved to %s.' % (fn, ))

def pastebin(self, s=None):

"""Upload to a pastebin and display the URL in the status bar."""

if s is None:

s = self.getstdout()

if (self.config.pastebin_confirm and

not self.interact.confirm(_("Pastebin buffer? (y/N) "))):

self.interact.notify(_("Pastebin aborted"))

return

return self.do_pastebin(s)

def do_pastebin(self, s):

"""Actually perform the upload."""

if s == self.prev_pastebin_content:

self.interact.notify(_('Duplicate pastebin. Previous URL: %s') %

(self.prev_pastebin_url, ))

return self.prev_pastebin_url

if self.config.pastebin_helper:

return self.do_pastebin_helper(s)

else:

return self.do_pastebin_xmlrpc(s)

def do_pastebin_xmlrpc(self, s):

"""Upload to pastebin via XML-RPC."""

try:

pasteservice = ServerProxy(self.config.pastebin_url)

except IOError, e:

self.interact.notify(_("Pastebin error for URL '%s': %s") %

(self.config.pastebin_url, str(e)))

return

self.interact.notify(_('Posting data to pastebin...'))

try:

paste_id = pasteservice.pastes.newPaste('pycon', s, '', '', '',

self.config.pastebin_private)

except (SocketError, XMLRPCError), e:

self.interact.notify(_('Upload failed: %s') % (str(e), ) )

return

self.prev_pastebin_content = s

paste_url_template = Template(self.config.pastebin_show_url)

paste_id = urlquote(paste_id)

paste_url = paste_url_template.safe_substitute(paste_id=paste_id)

self.prev_pastebin_url = paste_url

self.interact.notify(_('Pastebin URL: %s') % (paste_url, ), 10)

return paste_url

def do_pastebin_helper(self, s):

"""Call out to helper program for pastebin upload."""

self.interact.notify(_('Posting data to pastebin...'))

try:

helper = subprocess.Popen('',

executable=self.config.pastebin_helper,

stdin=subprocess.PIPE,

stdout=subprocess.PIPE)

helper.stdin.write(s.encode(getpreferredencoding()))

output = helper.communicate()[0].decode(getpreferredencoding())

paste_url = output.split()[0]

except OSError, e:

if e.errno == errno.ENOENT:

self.interact.notify(_('Upload failed: '

'Helper program not found.'))

else:

self.interact.notify(_('Upload failed: '

'Helper program could not be run.'))

return

if helper.returncode != 0:

self.interact.notify(_('Upload failed: '

'Helper program returned non-zero exit '

'status %s.' % (helper.returncode, )))

return

if not paste_url:

self.interact.notify(_('Upload failed: '

'No output from helper program.'))

return

else:

parsed_url = urlparse(paste_url)

if (not parsed_url.scheme

or any(unicodedata.category(c) == 'Cc' for c in paste_url)):

self.interact.notify(_("Upload failed: "

"Failed to recognize the helper "

"program's output as an URL."))

return

self.prev_pastebin_content = s

self.interact.notify(_('Pastebin URL: %s') % (paste_url, ), 10)

return paste_url

def push(self, s, insert_into_history=True):

"""Push a line of code onto the buffer so it can process it all

at once when a code block ends"""

s = s.rstrip('\n')

self.buffer.append(s)

if insert_into_history:

self.insert_into_history(s)

more = self.interp.runsource('\n'.join(self.buffer))

if not more:

self.buffer = []

return more

def insert_into_history(self, s):

if self.config.hist_length:

histfilename = os.path.expanduser(self.config.hist_file)

oldhistory = self.rl_history.entries

self.rl_history.entries = []

if os.path.exists(histfilename):

self.rl_history.load(histfilename, getpreferredencoding())

self.rl_history.append(s)

try:

self.rl_history.save(histfilename, getpreferredencoding(), self.config.hist_length)

except EnvironmentError, err:

self.interact.notify("Error occured while writing to file %s (%s) " % (histfilename, err.strerror))

self.rl_history.entries = oldhistory

self.rl_history.append(s)

else:

self.rl_history.append(s)

def undo(self, n=1):

"""Go back in the undo history n steps and call reeavluate()

Note that in the program this is called "Rewind" because I

want it to be clear that this is by no means a true undo

implementation, it is merely a convenience bonus."""

if not self.history:

return None

if len(self.history) < n:

n = len(self.history)

entries = list(self.rl_history.entries)

self.history = self.history[:-n]

self.reevaluate()

self.rl_history.entries = entries

def flush(self):

"""Olivier Grisel brought it to my attention that the logging

module tries to call this method, since it makes assumptions

about stdout that may not necessarily be true. The docs for

sys.stdout say:

"stdout and stderr needn't be built-in file objects: any

object is acceptable as long as it has a write() method

that takes a string argument."

So I consider this to be a bug in logging, and this is a hack

to fix it, unfortunately. I'm sure it's not the only module

to do it."""

def close(self):

"""See the flush() method docstring."""

def tokenize(self, s, newline=False):

"""Tokenizes a line of code, returning pygments tokens

with side effects/impurities:

- reads self.cpos to see what parens should be highlighted

- reads self.buffer to see what came before the passed in line

- sets self.highlighted_paren to (buffer_lineno, tokens_for_that_line) for buffer line

that should replace that line to unhighlight it

- calls reprint_line with a buffer's line's tokens and the buffer lineno that has changed

iff that line is the not the current line

"""

source = '\n'.join(self.buffer + [s])

cursor = len(source) - self.cpos

if self.cpos:

cursor += 1

stack = list()

all_tokens = list(PythonLexer().get_tokens(source))

# Unfortunately, Pygments adds a trailing newline and strings with

# no size, so strip them

while not all_tokens[-1][1]:

all_tokens.pop()

all_tokens[-1] = (all_tokens[-1][0], all_tokens[-1][1].rstrip('\n'))

line = pos = 0

parens = dict(zip('{([', '})]'))

line_tokens = list()

saved_tokens = list()

search_for_paren = True

for (token, value) in split_lines(all_tokens):

pos += len(value)

if token is Token.Text and value == '\n':

line += 1

# Remove trailing newline

line_tokens = list()

saved_tokens = list()

continue

line_tokens.append((token, value))

saved_tokens.append((token, value))

if not search_for_paren:

continue

under_cursor = (pos == cursor)

if token is Token.Punctuation:

if value in parens:

if under_cursor:

line_tokens[-1] = (Parenthesis.UnderCursor, value)

# Push marker on the stack

stack.append((Parenthesis, value))

else:

stack.append((line, len(line_tokens) - 1,

line_tokens, value))

elif value in parens.itervalues():

saved_stack = list(stack)

try:

while True:

opening = stack.pop()

if parens[opening[-1]] == value:

break

except IndexError:

# SyntaxError.. more closed parentheses than

# opened or a wrong closing paren

opening = None

if not saved_stack:

search_for_paren = False

else:

stack = saved_stack

if opening and opening[0] is Parenthesis:

# Marker found

line_tokens[-1] = (Parenthesis, value)

search_for_paren = False

elif opening and under_cursor and not newline:

if self.cpos:

line_tokens[-1] = (Parenthesis.UnderCursor, value)

else:

# The cursor is at the end of line and next to

# the paren, so it doesn't reverse the paren.