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.buffer = []
self.interp = interp
self.interp.syntaxerror_callback = self.clear_current_line
self.match = False
self.s = ""
self.cpos = 0
self.s_hist = []
self.rl_history = History(allow_duplicates=self.config.hist_duplicates)
self.stdin_history = History()
self.stdout_history = History()
self.evaluating = False
self.completer = BPythonCompleter(self.interp.locals, config)
self.parser = ReplParser(self)
self.matches = []
self.matches_iter = MatchesIterator()
self.argspec = None
self.list_win_visible = False
self._C = {}
self.interact = Interaction(self.config)
self.ps1 = '>>> '
self.ps2 = '... '
# 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")
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, current_word
"""
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.buffer = []
self.interp = interp
self.interp.syntaxerror_callback = self.clear_current_line
self.match = False
self.s = ""
self.cpos = 0
self.s_hist = []
self.rl_history = History(allow_duplicates=self.config.hist_duplicates)
self.stdin_history = History()
self.stdout_history = History()
self.evaluating = False
self.completer = BPythonCompleter(self.interp.locals, config)
self.parser = ReplParser(self)
self.matches = []
self.matches_iter = MatchesIterator()
self.argspec = None
self.list_win_visible = False
self._C = {}
self.interact = Interaction(self.config)
self.ps1 = '>>> '
self.ps2 = '... '
# 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")
def register_command(self, name, function=None, without_completion=False):
def inner(function, name=name):
if not name:
name = function.__name__.replace('_', '-')
if self.interp.register_command(name, function) and not without_completion:
name += " "
self.completer.register_command(name)
if not function:
return inner
else:
return inner(function, name)
@property
def history(self):
return self.stdin_history
@property
def current_line(self):
raise (NotImplementedError("current_line should be implemented in subclass"))
def clear_current_line(self):
"""This is used as the exception callback for the Interpreter instance.
It prevents autoindentation from occuring after a traceback."""
raise (NotImplementedError("clear_current_line should be implemented in subclass"))
def reevaluate(self):
raise (NotImplementedError("reevaluate should be implemented in subclass"))
def tab(self):
raise (NotImplementedError("tab should be implemented in subclass"))
def tokenize(self, s, newline=False):
"""Tokenize a line of code."""
return self.parser.tokenize(s, newline)
def startup(self):
"""
Execute PYTHONSTARTUP file if it exits. Call this after front
end-specific initialisation.
"""
self.interp.startup()
@property
def stdout(self):
return str(self.stdout_history)
@property
def stdin(self):
return str(self.stdin_history)
@property
def current_string(self):
"""If the line ends in a string get it, otherwise return ''"""
return self.parser.get_current_string()
@property
def current_word(self):
"""Return the current word, i.e. the (incomplete) word directly to the
left of the cursor"""
return self.parser.get_current_word()
def get_current_sbracket(self):
return self.parser.get_current_sbracket()
@property
def is_first_word(self):
return self.parser.is_first_word()
@property
def is_only_word(self):
return self.parser.is_only_word()
@property
def is_assignment_statement(self):
return self.parser.is_assignment_statement()
def get_object(self, name):
return self.interp.get_object(name)
def set_argspec(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"""
if not self.config.arg_spec:
self.argspec = None
else:
func, arg_number = self.parser.get_current_func()
self.argspec = self.interp.get_argspec(self, func, arg_number)
@property
def current_object(self):
"""Return the object which is bound to the
current name in the current input line. Return `None` if the
source cannot be found."""
obj = None
line = self.current_line
if inspection.is_eval_safe_name(line):
obj = self.get_object(line)
return obj
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."""
self.set_argspec()
current_word = self.current_word
current_string = self.current_string
sb_expr, sb_attr = self.get_current_sbracket()
line = self.current_line.lstrip()
if sb_expr:
self.completer.get_item_complete(sb_expr, sb_attr)
self.matches = self.completer.matches
self.matches_iter.update(sb_attr, self.matches)
return bool(self.matches)
elif not current_word:
self.matches = []
self.matches_iter.update()
return bool(self.argspec)
elif not (current_word or current_string):
return bool(self.argspec)
elif current_string:
if tab:
# Filename completion
self.completer.file_complete(current_string)
self.matches = self.completer.matches
self.matches_iter.update(current_string, self.matches)
return bool(self.matches)
else:
# Do not provide suggestions inside strings, as one cannot tab
# them so they would be really confusing.
self.matches = []
self.matches_iter.update()
return False
elif (self.config.complete_magic_methods
and self.buffer
and self.buffer[0].startswith("class ")
and line.startswith('def ')):
self.matches = [name for name in self.config.magic_methods
if name.startswith(current_word)]
self.matches_iter.update(current_word, self.matches)
return bool(self.matches)
elif line.startswith('class ') or line.startswith('def '):
self.matches = []
self.matches_iter.update()
return False
elif line.startswith('from ') or line.startswith('import '):
self.completer.import_complete(current_word, self.current_line)
self.matches = self.completer.matches
self.matches_iter.update(current_word, self.matches)
return bool(self.matches)
e = False
try:
if len(self.buffer) == 0 and self.is_first_word:
self.completer.complete(current_word, with_command=True)
else:
self.completer.complete(current_word)
except (AttributeError, re.error, TimeOutException):
e = True
except Exception as err:
raise err
# This sucks, but it's either that or list all the exceptions that could
# possibly be raised here, so if anyone wants to do that, feel free to send me
# a patch. XXX: Make sure you raise here if you're debugging the completion
# stuff !
e = True
else:
matches = self.completer.matches
if not e and self.argspec and isinstance(self.argspec, inspection.ArgSpec):
matches.extend(name + '=' for name in self.argspec[1][0]
if isinstance(name, basestring) and name.startswith(current_word))
if PY3:
matches.extend(name + '=' for name in self.argspec[1][4]
if name.startswith(current_word))
if e or not matches:
self.matches = []
self.matches_iter.update()
if not self.argspec:
return False
else:
# remove duplicates
self.matches = sorted(set(matches))
if len(self.matches) == 1 and not self.config.auto_display_list:
self.list_win_visible = True
self.tab()
return False
self.matches_iter.update(current_word, self.matches)
return True
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 += '.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.stdout)
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 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"""
if s.lstrip(' ') and s.lstrip(' ')[0] == '!':
self.buffer = []
return
s = s.rstrip('\n')
self.buffer.append(s)
if insert_into_history:
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 as e:
self.interact.notify("Error occured while writing to file %s (%s) " % (histfilename, e.strerror))
self.rl_history.entries = oldhistory
self.rl_history.append(s)
else:
self.rl_history.append(s)
if len(self.buffer) == 1:
line = self.buffer[0]
if self.interp.is_commandline(line) and not self.is_assignment_statement:
result = self.interp.runcommand(line)
self.buffer = []
return result
more = self.interp.runsource('\n'.join(self.buffer))
if not more:
self.buffer = []
return more
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.entries = 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."""