# encoding: utf-8

from __future__ import absolute_import

import linecache

class BPythonLinecache(dict):

"""Replaces the cache dict in the standard-library linecache module,

to also remember (in an unerasable way) bpython console input."""

def __init__(self, *args, **kwargs):

super(BPythonLinecache, self).__init__(*args, **kwargs)

self.bpython_history = []

def is_bpython_filename(self, fname):

try:

return fname.startswith('<bpython-input-')

except AttributeError:

# In case the key isn't a string

return False

def get_bpython_history(self, key):

"""Given a filename provided by remember_bpython_input,

returns the associated source string."""

try:

idx = int(key.split('-')[2][:-1])

return self.bpython_history[idx]

except (IndexError, ValueError):

raise KeyError

def remember_bpython_input(self, source):

"""Remembers a string of source code, and returns

a fake filename to use to retrieve it later."""

filename = '<bpython-input-%s>' % len(self.bpython_history)

self.bpython_history.append((len(source), None,

source.splitlines(True), filename))

return filename

def __getitem__(self, key):

if self.is_bpython_filename(key):

return self.get_bpython_history(key)

return super(BPythonLinecache, self).__getitem__(key)

def __contains__(self, key):

if self.is_bpython_filename(key):

try:

self.get_bpython_history(key)

return True

except KeyError:

return False

return super(BPythonLinecache, self).__contains__(key)

def __delitem__(self, key):

if not self.is_bpython_filename(key):

return super(BPythonLinecache, self).__delitem__(key)

def _bpython_clear_linecache():

try:

bpython_history = linecache.cache.bpython_history

except AttributeError:

bpython_history = []

linecache.cache = BPythonLinecache()

linecache.cache.bpython_history = bpython_history

# Monkey-patch the linecache module so that we're able

# to hold our command history there and have it persist

linecache.cache = BPythonLinecache(linecache.cache)

linecache.clearcache = _bpython_clear_linecache

def filename_for_console_input(code_string):

"""Remembers a string of source code, and returns

a fake filename to use to retrieve it later."""

try:

return linecache.cache.remember_bpython_input(code_string)

except AttributeError:

# If someone else has patched linecache.cache, better for code to

# simply be unavailable to inspect.getsource() than to raise

# an exception.

return '<input>'