# RemotePyInterpreter

- `Download example`

A PyObjC Example without documentation

## Sources

### AsyncPythonInterpreter.py

    __all__ = ["AsyncPythonInterpreter"]

    import fcntl
    import os
    import socket
    import sys

    import objc
    from Foundation import (
        NSObject,
        NSUserDefaults,
        NSLog,
        NSFileHandle,
        NSNotificationCenter,
        NSFileHandleConnectionAcceptedNotification,
        NSTask,
        NSTaskDidTerminateNotification,
        NSFileHandleNotificationFileHandleItem,
        NSFileHandleReadCompletionNotification,
        NSFileHandleError,
        NSData,
        NSFileHandleNotificationDataItem,
    )

    IMPORT_MODULES = ["netrepr", "remote_console", "remote_pipe", "remote_bootstrap"]
    source = []
    for fn in IMPORT_MODULES:
        for line in open(fn + ".py", "rU"):
            source.append(line)
        source.append("\n\n")
    SOURCE = repr("".join(source)) + "\n"

    def bind_and_listen(hostport):
        if isinstance(hostport, str):
            host, port = hostport.split(":")
            hostport = (host, int(port))
        serversock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        # set close-on-exec
        if hasattr(fcntl, "FD_CLOEXEC"):
            old = fcntl.fcntl(serversock.fileno(), fcntl.F_GETFD)
            fcntl.fcntl(serversock.fileno(), fcntl.F_SETFD, old | fcntl.FD_CLOEXEC)
        # allow the address to be re-used in a reasonable amount of time
        if os.name == "posix" and sys.platform != "cygwin":
            serversock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

        serversock.bind(hostport)
        serversock.listen(5)
        return serversock

    class AsyncPythonInterpreter(NSObject):

        commandReactor = objc.IBOutlet("commandReactor")

        def init(self):
            self = super(AsyncPythonInterpreter, self).init()
            self.host = None
            self.port = None
            self.interpreterPath = None
            self.scriptPath = None
            self.commandReactor = None
            self.serverSocket = None
            self.serverFileHandle = None
            self.buffer = ""
            self.serverFileHandle = None
            self.remoteFileHandle = None
            self.childTask = None
            return self

        def initWithHost_port_interpreterPath_scriptPath_commandReactor_(
            self, host, port, interpreterPath, scriptPath, commandReactor
        ):
            self = self.init()
            self.host = host
            self.port = port
            self.interpreterPath = interpreterPath
            self.scriptPath = scriptPath
            self.commandReactor = commandReactor
            self.serverSocket = None
            return self

        def awakeFromNib(self):
            defaults = NSUserDefaults.standardUserDefaults()

            def default(k, v, typeCheck=None):
                rval = defaults.objectForKey_(k)
                if typeCheck is not None and rval is not None:
                    try:
                        rval = typeCheck(rval)
                    except TypeError:
                        NSLog(
                            "%s failed type check %s with value %s",
                            k,
                            typeCheck.__name__,
                            rval,
                        )
                        rval = None
                if rval is None:
                    defaults.setObject_forKey_(v, k)
                    rval = v
                return rval

            self.host = default("AsyncPythonInterpreterInterpreterHost", "127.0.0.1", str)
            self.port = default("AsyncPythonInterpreterInterpreterPort", 0, int)
            self.interpreterPath = default(
                "AsyncPythonInterpreterInterpreterPath", "/usr/bin/python", str
            )
            self.scriptPath = (
                type(self).bundleForClass().pathForResource_ofType_("tcpinterpreter", "py")
            )

        def connect(self):
            # NSLog(u'connect')
            self.serverSocket = bind_and_listen((self.host, self.port))
            self.serverFileHandle = NSFileHandle.alloc().initWithFileDescriptor_(
                self.serverSocket.fileno()
            )
            nc = NSNotificationCenter.defaultCenter()
            nc.addObserver_selector_name_object_(
                self,
                "remoteSocketAccepted:",
                NSFileHandleConnectionAcceptedNotification,
                self.serverFileHandle,
            )
            self.serverFileHandle.acceptConnectionInBackgroundAndNotify()
            self.remoteFileHandle = None
            for k in os.environ.keys():
                if k.startswith("PYTHON"):
                    del os.environ[k]
            self.childTask = NSTask.launchedTaskWithLaunchPath_arguments_(
                self.interpreterPath,
                [self.scriptPath, repr(self.serverSocket.getsockname())],
            )
            nc.addObserver_selector_name_object_(
                self, "childTaskTerminated:", NSTaskDidTerminateNotification, self.childTask
            )
            return self

        def remoteSocketAccepted_(self, notification):
            # NSLog(u'remoteSocketAccepted_')
            self.serverFileHandle.closeFile()
            self.serverFileHandle = None
            ui = notification.userInfo()
            self.remoteFileHandle = ui.objectForKey_(NSFileHandleNotificationFileHandleItem)
            nc = NSNotificationCenter.defaultCenter()
            nc.addObserver_selector_name_object_(
                self,
                "remoteFileHandleReadCompleted:",
                NSFileHandleReadCompletionNotification,
                self.remoteFileHandle,
            )
            self.writeBytes_(SOURCE)
            self.remoteFileHandle.readInBackgroundAndNotify()
            self.commandReactor.connectionEstablished_(self)
            NSNotificationCenter.defaultCenter().postNotificationName_object_(
                "AsyncPythonInterpreterOpened", self
            )

        def remoteFileHandleReadCompleted_(self, notification):
            # NSLog(u'remoteFileHandleReadCompleted_')
            ui = notification.userInfo()
            newData = ui.objectForKey_(NSFileHandleNotificationDataItem)
            if newData is None:
                self.close()
                NSLog("Error: %@", ui.objectForKey_(NSFileHandleError))
                return
            data_bytes = newData.bytes()[:]
            if len(data_bytes) == 0:
                self.close()
                return
            self.remoteFileHandle.readInBackgroundAndNotify()
            start = len(self.buffer)
            buff = self.buffer + newData.bytes()[:]
            # NSLog(u'current buffer: %s', buff)
            lines = []
            while True:
                linebreak = buff.find("\n", start) + 1
                if linebreak == 0:
                    break
                lines.append(buff[:linebreak])
                buff = buff[linebreak:]
                start = 0
            # NSLog(u'lines: %s', lines)
            self.buffer = buff
            for line in lines:
                self.commandReactor.lineReceived_fromConnection_(line, self)

        def writeBytes_(self, data):
            # NSLog(u'Writing bytes: %s', data)
            try:
                self.remoteFileHandle.writeData_(
                    NSData.dataWithBytes_length_(data, len(data))
                )
            except objc.error:
                self.close()
            # NSLog(u'bytes written.')

        def childTaskTerminated_(self, notification):
            # NSLog(u'childTaskTerminated_')
            self.close()

        def closeServerFileHandle(self):
            # NSLog(u'closeServerFileHandle')
            if self.serverFileHandle is not None:
                try:
                    self.serverFileHandle.closeFile()
                except objc.error:
                    pass
                self.serverFileHandle = None

        def closeRemoteFileHandle(self):
            # NSLog(u'closeRemoteFileHandle')
            if self.remoteFileHandle is not None:
                try:
                    self.remoteFileHandle.closeFile()
                except objc.error:
                    pass
                self.remoteFileHandle = None

        def terminateChildTask(self):
            # NSLog(u'terminateChildTask')
            if self.childTask is not None:
                try:
                    self.childTask.terminate()
                except objc.error:
                    pass
                self.childTask = None

        def close(self):
            # NSLog(u'close')
            NSNotificationCenter.defaultCenter().removeObserver_(self)
            self.finalClose()
            NSNotificationCenter.defaultCenter().postNotificationName_object_(
                "AsyncPythonInterpreterClosed", self
            )

        def finalClose(self):
            if self.commandReactor is not None:
                self.commandReactor.connectionClosed_(self)
                self.commandReactor = None
            self.closeServerFileHandle()
            self.closeRemoteFileHandle()
            self.terminateChildTask()

    def test_console():
        from PyObjCTools import AppHelper
        from ConsoleReactor import ConsoleReactor

        host = "127.0.0.1"
        port = 0
        interpreterPath = sys.executable
        scriptPath = os.path.abspath("tcpinterpreter.py")
        commandReactor = ConsoleReactor.alloc().init()
        interp = AsyncPythonInterpreter.alloc().initWithHost_port_interpreterPath_scriptPath_commandReactor_(  # noqa: B950
            host, port, interpreterPath, scriptPath, commandReactor
        )
        interp.connect()

        class ThisEventLoopStopper(NSObject):
            def interpFinished_(self, notification):
                AppHelper.stopEventLoop()

        stopper = ThisEventLoopStopper.alloc().init()
        NSNotificationCenter.defaultCenter().addObserver_selector_name_object_(
            stopper, "interpFinished:", "AsyncPythonInterpreterClosed", interp
        )
        AppHelper.runConsoleEventLoop(installInterrupt=True)

    def main():
        test_console()

    if __name__ == "__main__":
        main()

### ConsoleReactor.py

    from __future__ import print_function

    import sys

    from Foundation import NSObject, NSLog
    from netrepr import NetRepr, RemoteObjectPool, RemoteObjectReference

    __all__ = ["ConsoleReactor"]

    class ConsoleReactor(NSObject):
        def init(self):
            self = super(ConsoleReactor, self).init()
            self.pool = None
            self.netReprCenter = None
            self.connection = None
            self.commands = {}
            return self

        def connectionEstablished_(self, connection):
            # NSLog(u'connectionEstablished_')
            self.connection = connection
            self.pool = RemoteObjectPool(self.writeCode_)
            self.netReprCenter = NetRepr(self.pool)

        def connectionClosed_(self, connection):
            # NSLog(u'connectionClosed_')
            self.connection = None
            self.pool = None
            self.netReprCenter = None

        def writeCode_(self, code):
            # NSLog(u'writeCode_')
            self.connection.writeBytes_(repr(code) + "\n")

        def netEval_(self, s):
            # NSLog(u'netEval_')
            return eval(s, self.pool.namespace, self.pool.namespace)

        def lineReceived_fromConnection_(self, lineReceived, connection):
            # NSLog(u'lineReceived_fromConnection_')
            code = lineReceived.rstrip()
            if not code:
                return
            self.pool.push()
            command = map(self.netEval_, eval(code))
            try:
                self.handleCommand_(command)
            finally:
                self.pool.pop()

        def handleCommand_(self, command):
            # NSLog(u'handleCommand_')
            basic = command[0]
            sel = "handle%sCommand:" % (basic.capitalize())
            cmd = command[1:]
            if not self.respondsToSelector_(sel):
                NSLog("%r does not respond to %s", self, command)
            else:
                self.performSelector_withObject_(sel, cmd)
                getattr(self, sel.replace(":", "_"))(cmd)

        def handleRespondCommand_(self, command):
            self.doCallback_sequence_args_(
                self.commands.pop(command[0]), command[0], map(self.netEval_, command[1:])
            )

        def sendResult_sequence_(self, rval, seq):
            nr = self.netReprCenter
            code = "__result__[%r] = %s" % (seq, nr.netrepr(rval))
            self.writeCode_(code)

        def sendException_sequence_(self, e, seq):
            nr = self.netReprCenter
            code = "raise " + nr.netrepr_exception(e)
            print("forwarding:", code)
            self.writeCode_(code)

        def doCallback_sequence_args_(self, callback, seq, args):
            # nr = self.netReprCenter
            try:
                rval = callback(*args)
            except Exception as e:
                self.sendException_sequence_(e, seq)
            else:
                self.sendResult_sequence_(rval, seq)

        def deferCallback_sequence_value_(self, callback, seq, value):
            self.commands[seq] = callback
            self.writeCode_("pipe.respond(%r, netrepr(%s))" % (seq, value))

        def handleExpectCommand_(self, command):
            # NSLog(u'handleExpectCommand_')
            seq = command[0]
            name = command[1]
            args = command[2:]
            netrepr = self.netReprCenter.netrepr
            if name == "RemoteConsole.raw_input":
                self.doCallback_sequence_args_(input, seq, args)
            elif name == "RemoteConsole.write":
                self.doCallback_sequence_args_(sys.stdout.write, seq, args)
            elif name == "RemoteConsole.displayhook":
                obj = args[0]

                def displayhook_respond(reprobject):
                    print(reprobject)

                def displayhook_local(obj):
                    if obj is not None:
                        displayhook_respond(repr(obj))

                if isinstance(obj, RemoteObjectReference):
                    self.deferCallback_sequence_value_(
                        displayhook_respond, seq, "repr(%s)" % (netrepr(obj),)
                    )
                else:
                    self.doCallback_sequence_args_(displayhook_local, seq, args)
            elif name.startswith("RemoteFileLike."):
                fh = getattr(sys, args[0])
                meth = getattr(fh, name[len("RemoteFileLike.") :])  # noqa: E203
                self.doCallback_sequence_args_(meth, seq, args[1:])
            elif name == "RemoteConsole.initialize":
                self.doCallback_sequence_args_(lambda *args: None, seq, args)
            else:
                self.doCallback_sequence_args_(
                    NSLog, seq, ["%r does not respond to expect %r", self, command]
                )

        def close(self):
            if self.connection is not None:
                self.writeCode_("raise SystemExit")
            self.pool = None
            self.netReprCenter = None
            self.connection = None
            self.commands = None

### RemotePyInterpreter.py

    import objc

    from Cocoa import (
        NSLog,
        NSDocument,
        NSFont,
        NSColor,
        NSAttributedString,
        NSFontAttributeName,
        NSForegroundColorAttributeName,
    )

    # from AsyncPythonInterpreter import *
    from ConsoleReactor import ConsoleReactor
    from netrepr import RemoteObjectReference
    from PyObjCTools import AppHelper

    def ensure_unicode(s):
        if not isinstance(s, str):
            s = str(s, "utf-8", "replace")
        return s

    class RemotePyInterpreterReactor(ConsoleReactor):
        delegate = objc.IBOutlet()

        def handleExpectCommand_(self, command):
            print(command)
            seq = command[0]
            name = command[1]
            args = command[2:]
            netrepr = self.netReprCenter.netrepr
            if name == "RemoteConsole.raw_input":
                prompt = ensure_unicode(args[0])

                def input_received(line):
                    self.sendResult_sequence_(line, seq)

                self.delegate.expectCodeInput_withPrompt_(input_received, prompt)
            elif name == "RemoteConsole.write":
                args = [ensure_unicode(args[0]), "code"]
                self.doCallback_sequence_args_(
                    self.delegate.writeString_forOutput_, seq, args
                )
            elif name == "RemoteConsole.displayhook":
                obj = args[0]

                def displayhook_respond(reprobject):
                    self.delegate.writeString_forOutput_(
                        ensure_unicode(reprobject) + "\n", "code"
                    )

                def displayhook_local(obj):
                    if obj is not None:
                        displayhook_respond(repr(obj))

                if isinstance(obj, RemoteObjectReference):
                    self.deferCallback_sequence_value_(
                        displayhook_respond, seq, "repr(%s)" % (netrepr(obj),)
                    )
                else:
                    self.doCallback_sequence_args_(displayhook_local, seq, args)
            elif name.startswith("RemoteFileLike."):
                method = name[len("RemoteFileLike.") :]  # noqa: E203
                if method == "write":
                    style, msg = map(ensure_unicode, args)
                    args = [msg, style]
                    self.doCallback_sequence_args_(
                        self.delegate.writeString_forOutput_, seq, args
                    )

                elif method == "readline":

                    def input_received(line):
                        self.sendResult_sequence_(line, seq)

                    self.delegate.expectCodeInput_withPrompt_(input_received, "")

                else:
                    self.doCallback_sequence_args_(
                        NSLog, seq, ["%s does not respond to expect %s", self, command]
                    )
            elif name == "RemoteConsole.initialize":

                def gotTitle(repr_versioninfo, executable, pid):
                    self.delegate.setVersion_executable_pid_(
                        ".".join(map(str, self.netEval_(repr_versioninfo)[:3])),
                        ensure_unicode(executable),
                        pid,
                    )

                self.doCallback_sequence_args_(gotTitle, seq, args)
            #    fh = getattr(sys, args[0])
            #    meth = getattr(fh, name[len('RemoteFileLike.'):])
            #    self.doCallback_sequence_args_(meth, seq, args[1:])
            else:
                self.doCallback_sequence_args_(
                    NSLog, seq, ["%s does not respond to expect %s", self, command]
                )

        def close(self):
            super(RemotePyInterpreterReactor, self).close()
            self.delegate = None

    class PseudoUTF8Input(object):
        softspace = 0

        def __init__(self, readlinemethod):
            self._buffer = ""
            self._readline = readlinemethod

        def read(self, chars=None):
            if chars is None:
                if self._buffer:
                    rval = self._buffer
                    self._buffer = ""
                    if rval.endswith("\r"):
                        rval = rval[:-1] + "\n"
                    return rval.encode("utf-8")
                else:
                    return self._readline("\x04")[:-1].encode("utf-8")
            else:
                while len(self._buffer) < chars:
                    self._buffer += self._readline("\x04\r")
                    if self._buffer.endswith("\x04"):
                        self._buffer = self._buffer[:-1]
                        break
                rval, self._buffer = self._buffer[:chars], self._buffer[chars:]
                return rval.encode("utf-8").replace("\r", "\n")

        def readline(self):
            if "\r" not in self._buffer:
                self._buffer += self._readline("\x04\r")
            if self._buffer.endswith("\x04"):
                rval = self._buffer[:-1].encode("utf-8")
            elif self._buffer.endswith("\r"):
                rval = self._buffer[:-1].encode("utf-8") + "\n"
            self._buffer = ""

            return rval

    DEBUG_DELEGATE = 0
    PASSTHROUGH = ("deleteBackward:", "complete:", "moveRight:", "moveLeft:")

    class RemotePyInterpreterDocument(NSDocument):
        """
        PyInterpreter is a delegate/controller for a NSTextView,
        turning it into a full featured interactive Python interpreter.
        """

        commandReactor = objc.IBOutlet()
        interpreter = objc.IBOutlet()
        textView = objc.IBOutlet()

        def expectCodeInput_withPrompt_(self, callback, prompt):
            self.writeString_forOutput_(prompt, "code")
            self.setCharacterIndexForInput_(self.lengthOfTextView())
            self.p_input_callbacks.append(callback)
            self.flushCallbacks()

        def flushCallbacks(self):
            while self.p_input_lines and self.p_input_callbacks:
                self.p_input_callbacks.pop(0)(self.p_input_lines.pop(0))

        def setupTextView(self):
            self.textView.setFont_(self.font())
            self.textView.setContinuousSpellCheckingEnabled_(False)
            self.textView.setRichText_(False)
            self.setCharacterIndexForInput_(0)

        def setVersion_executable_pid_(self, version, executable, pid):
            self.version = version
            self.pid = pid
            self.executable = executable
            self.setFileName_(executable)

        def displayName(self):
            if not hasattr(self, "version"):
                return "Starting..."
            return "Python %s - %s - %s" % (self.version, self.executable, self.pid)

        def updateChangeCount_(self, val):
            return

        def windowWillClose_(self, window):
            if self.commandReactor is not None:
                self.commandReactor.close()
                self.commandReactor = None
            if self.interpreter is not None:
                self.interpreter.close()
                self.interpreter = None

        def windowNibName(self):
            return "RemotePyInterpreterDocument"

        def isDocumentEdited(self):
            return False

        def awakeFromNib(self):
            self.setFont_(NSFont.userFixedPitchFontOfSize_(10))
            self.p_colors = {
                "stderr": NSColor.redColor(),
                "stdout": NSColor.blueColor(),
                "code": NSColor.blackColor(),
            }
            self.setHistoryLength_(50)
            self.setHistoryView_(0)
            self.setInteracting_(False)
            self.setAutoScroll_(True)
            self.setSingleLineInteraction_(False)
            self.p_history = [""]
            self.p_input_callbacks = []
            self.p_input_lines = []
            self.setupTextView()
            self.interpreter.connect()

        #
        #  Modal input dialog support
        #

        # def p_nestedRunLoopReaderUntilEOLchars_(self, eolchars):
        #    """
        #    This makes the baby jesus cry.

        #    I want co-routines.
        #    """
        #    app = NSApplication.sharedApplication()
        #    window = self.textView.window()
        #    self.setCharacterIndexForInput_(self.lengthOfTextView())
        #    # change the color.. eh
        #    self.textView.setTypingAttributes_({
        #        NSFontAttributeName: self.font(),
        #        NSForegroundColorAttributeName: self.colorForName_(u'code'),
        #    })
        #    while True:
        #        event = app.nextEventMatchingMask_untilDate_inMode_dequeue_(
        #            NSAnyEventMask,
        #            NSDate.distantFuture(),
        #            NSDefaultRunLoopMode,
        #            True)
        #        if (event.type() == NSKeyDown) and (event.window() is window):
        #            eol = event.characters()
        #            if eol in eolchars:
        #                break
        #        app.sendEvent_(event)
        #    cl = self.currentLine()
        #    if eol == u'\r':
        #        self.writeNewLine()
        #    return cl + eol

        def executeLine_(self, line):
            self.addHistoryLine_(line)
            self.p_input_lines.append(line)
            self.flushCallbacks()
            self.p_history = filter(None, self.p_history)
            self.p_history.append("")
            self.setHistoryView_(len(self.p_history) - 1)

        def executeInteractiveLine_(self, line):
            self.setInteracting_(True)
            try:
                self.executeLine_(line)
            finally:
                self.setInteracting_(False)

        def replaceLineWithCode_(self, s):
            idx = self.characterIndexForInput()
            ts = self.textView.textStorage()
            s = self.formatString_forOutput_(s, "code")
            ts.replaceCharactersInRange_withAttributedString_(
                (idx, len(ts.mutableString()) - idx), s
            )

        #
        #  History functions
        #

        def addHistoryLine_(self, line):
            line = line.rstrip("\n")
            if self.p_history[-1] == line:
                return False
            if not line:
                return False
            self.p_history.append(line)
            if len(self.p_history) > self.historyLength():
                self.p_history.pop(0)
            return True

        def historyDown_(self, sender):
            if self.p_historyView == (len(self.p_history) - 1):
                return
            self.p_history[self.p_historyView] = self.currentLine()
            self.p_historyView += 1
            self.replaceLineWithCode_(self.p_history[self.p_historyView])
            self.moveToEndOfLine_(self)

        def historyUp_(self, sender):
            if self.p_historyView == 0:
                return
            self.p_history[self.p_historyView] = self.currentLine()
            self.p_historyView -= 1
            self.replaceLineWithCode_(self.p_history[self.p_historyView])
            self.moveToEndOfLine_(self)

        #
        #  Convenience methods to create/write decorated text
        #

        def formatString_forOutput_(self, s, name):
            return NSAttributedString.alloc().initWithString_attributes_(
                s,
                {
                    NSFontAttributeName: self.font(),
                    NSForegroundColorAttributeName: self.colorForName_(name),
                },
            )

        def writeString_forOutput_(self, s, name):
            s = self.formatString_forOutput_(s, name)
            self.textView.textStorage().appendAttributedString_(s)
            if self.isAutoScroll():
                self.textView.scrollRangeToVisible_((self.lengthOfTextView(), 0))

        def writeNewLine(self):
            self.writeString_forOutput_("\n", "code")

        def colorForName_(self, name):
            return self.p_colors[name]

        def setColor_forName_(self, color, name):
            self.p_colors[name] = color

        #
        #  Convenience methods for manipulating the NSTextView
        #

        def currentLine(self):
            return self.textView.textStorage().mutableString()[
                self.characterIndexForInput() :  # noqa: E203
            ]

        def moveAndScrollToIndex_(self, idx):
            self.textView.scrollRangeToVisible_((idx, 0))
            self.textView.setSelectedRange_((idx, 0))

        def lengthOfTextView(self):
            return len(self.textView.textStorage().mutableString())

        #
        #  NSTextViewDelegate methods
        #

        def textView_completions_forPartialWordRange_indexOfSelectedItem_(
            self, aTextView, completions, begin_length, index
        ):
            # NOTE:
            # this will probably have to be tricky in order to be asynchronous..
            # either by:
            #     nesting a run loop (bleh)
            #     polling the subprocess (bleh)
            #     returning nothing and calling self.textView.complete_ later
            begin, length = begin_length
            return None, 0

            if False:
                txt = self.textView.textStorage().mutableString()
                end = begin + length
                while (begin > 0) and (txt[begin].isalnum() or txt[begin] in "._"):
                    begin -= 1
                while not txt[begin].isalnum():
                    begin += 1
                return self.p_console.recommendCompletionsFor(txt[begin:end])

        def textView_shouldChangeTextInRange_replacementString_(
            self, aTextView, aRange, newString
        ):
            begin, length = aRange
            lastLocation = self.characterIndexForInput()
            if begin < lastLocation:
                # no editing anywhere but the interactive line
                return False
            newString = newString.replace("\r", "\n")
            if "\n" in newString:
                if begin != lastLocation:
                    # no pasting multiline unless you're at the end
                    # of the interactive line
                    return False
                # multiline paste support
                # self.clearLine()
                newString = self.currentLine() + newString
                for s in newString.strip().split("\n"):
                    self.writeString_forOutput_(s + "\n", "code")
                    self.executeLine_(s)
                return False
            return True

        def textView_willChangeSelectionFromCharacterRange_toCharacterRange_(
            self, aTextView, fromRange, toRange
        ):
            begin, length = toRange
            if (
                self.singleLineInteraction()
                and length == 0
                and begin < self.characterIndexForInput()
            ):
                # no cursor movement off the interactive line
                return fromRange
            else:
                return toRange

        def textView_doCommandBySelector_(self, aTextView, aSelector):
            # deleteForward: is ctrl-d
            if self.isInteracting():
                if aSelector == "insertNewline:":
                    self.writeNewLine()
                return False
            responder = getattr(self, aSelector.replace(":", "_"), None)
            if responder is not None:
                responder(aTextView)
                return True
            else:
                if DEBUG_DELEGATE and aSelector not in PASSTHROUGH:
                    print(aSelector)
                return False

        #
        #  doCommandBySelector "posers" on the textView
        #

        def insertTabIgnoringFieldEditor_(self, sender):
            # this isn't terribly necessary, b/c F5 and opt-esc do completion
            # but why not
            sender.complete_(self)

        def moveToBeginningOfLine_(self, sender):
            self.moveAndScrollToIndex_(self.characterIndexForInput())

        def moveToEndOfLine_(self, sender):
            self.moveAndScrollToIndex_(self.lengthOfTextView())

        def moveToBeginningOfLineAndModifySelection_(self, sender):
            begin, length = self.textView.selectedRange()
            pos = self.characterIndexForInput()
            if begin + length > pos:
                self.textView.setSelectedRange_((pos, begin + length - pos))
            else:
                self.moveToBeginningOfLine_(sender)

        def moveToEndOfLineAndModifySelection_(self, sender):
            begin, length = self.textView.selectedRange()
            pos = max(self.characterIndexForInput(), begin)
            self.textView.setSelectedRange_((pos, self.lengthOfTextView()))

        def insertNewline_(self, sender):
            line = self.currentLine()
            self.writeNewLine()
            self.executeInteractiveLine_(line)

        moveToBeginningOfParagraph_ = moveToBeginningOfLine_
        moveToEndOfParagraph_ = moveToEndOfLine_
        insertNewlineIgnoringFieldEditor_ = insertNewline_
        moveDown_ = historyDown_
        moveUp_ = historyUp_

        #
        #  Accessors
        #

        def historyLength(self):
            return self.p_historyLength

        def setHistoryLength_(self, length):
            self.p_historyLength = length

        def font(self):
            return self.p_font

        def setFont_(self, font):
            self.p_font = font

        def isInteracting(self):
            return self.p_interacting

        def setInteracting_(self, v):
            self.p_interacting = v

        def isAutoScroll(self):
            return self.p_autoScroll

        def setAutoScroll_(self, v):
            self.p_autoScroll = v

        def characterIndexForInput(self):
            return self.p_characterIndexForInput

        def setCharacterIndexForInput_(self, idx):
            self.p_characterIndexForInput = idx
            self.moveAndScrollToIndex_(idx)

        def historyView(self):
            return self.p_historyView

        def setHistoryView_(self, v):
            self.p_historyView = v

        def singleLineInteraction(self):
            return self.p_singleLineInteraction

        def setSingleLineInteraction_(self, v):
            self.p_singleLineInteraction = v

    if __name__ == "__main__":
        AppHelper.runEventLoop(installInterrupt=True)

### netrepr.py

    import itertools

    def type_string(obj):
        if isinstance(obj, type):
            objType = obj.__class__
        else:
            objType = type(obj)
        return getattr(objType, "__module__", "-") + "." + objType.__name__

    class NetRepr(object):
        def __init__(self, objectPool):
            self.objectPool = objectPool
            self.cache = {}
            self._identfactory = itertools.count()

        def clear(self):
            self.cache.clear()
            self._identfactory = itertools.count()

        def netrepr_tuple(self, obj):
            return repr(tuple(itertools.imap(self.netrepr, obj)))

        def netrepr_list(self, obj):
            return repr(map(self.netrepr, obj))

        def netrepr_exception(self, e):
            cls = e.__class__
            if cls.__module__ == "exceptions":
                rval = cls.__name__ + self.netrepr_tuple(e.args)
            else:
                rval = "Exception(%r)" % (
                    "[Remote] %s.%s %s" % (cls.__module__, cls.__name__, e),
                )
            return rval

        def netrepr(self, obj):
            if obj is None:
                return "None"
            objtype = type(obj)
            if objtype is int or objtype is float:
                return repr(obj)
            elif objtype is str:
                if True:
                    return repr(obj)
                else:
                    # "intern" these
                    obj_id = id(obj)
                    cached = self.get(self.cache, obj_id, None)
                    if cached is None:
                        # ident = next(self._identfactory)
                        self.cache[obj_id] = "__cached__(%r)" % (obj_id,)
                        cached = "__cache__(%r, %r)" % (obj_id, obj)
                    return cached
            return self.netrepr_default(obj)

        def netrepr_default(self, obj):
            method = getattr(obj, "__netrepr__", None)
            if method is None:
                method = self.objectPool.referenceForObject(obj).__netrepr__
            return method()

    class BaseObjectPool(object):
        def __init__(self):
            self.idents = {}
            self.refs = {}
            self.pools = []

        def referenceForIdent(self, ident):
            return self.idents[ident]

        def base_alloc(self, ref, ident):
            self.refs[ref] = ident
            self.idents[ident] = ref

        def base_dealloc(self, ref, ident):
            del self.refs[ref]
            del self.idents[ident]

        def autorelease(self, ref):
            if not self.pools:
                raise RuntimeError("no autoreleasepool for %r" % (ref,))
            pool = self.pools[-1]
            pool[ref] = pool.get(ref, 0) + 1

        def push(self):
            # print "pushed pool"
            self.pools.append({})

        def pop(self):
            if not self.pools:
                raise RuntimeError("popped too many pools")
            # print "popped pool"
            pool = self.pools.pop()
            for ref, count in pool.items():
                ref.release(count)

        def referenceForObject(self, obj):
            raise TypeError(
                "Can not create a reference to %r, the bridge is unidirectional" % (obj,)
            )

    class RemoteObjectPool(BaseObjectPool):
        def __init__(self, writecode):
            BaseObjectPool.__init__(self)
            self.writecode = writecode
            self.namespace = {"None": None, "__ref__": self.referenceForRemoteIdent}

        def referenceForRemoteIdent(self, ident, type_string):
            rval = self.idents.get(ident)
            if rval is None:
                rval = RemoteObjectReference(self, ident, type_string)
            return rval

    class ObjectPool(BaseObjectPool):
        def __init__(self):
            BaseObjectPool.__init__(self)
            self._identfactory = itertools.count()
            self.obj_ids = {}
            self.namespace = {"__obj__": self.objectForIdent}

        def object_alloc(self, ref, obj_id):
            self.obj_ids[obj_id] = ref

        def object_dealloc(self, ref, obj_id):
            del self.obj_ids[obj_id]

        def objectForIdent(self, ident):
            return self.referenceForIdent(ident).obj

        def referenceForObject(self, obj):
            obj_id = id(obj)
            rval = self.obj_ids.get(obj_id)
            if rval is None:
                ident = next(self._identfactory)
                rval = ObjectReference(self, ident, type_string(obj), obj, obj_id)
                rval = rval.alloc().autorelease()
            return rval

    class BaseObjectReference(object):
        def __init__(self, objectPool, ident, type_string):
            self.ident = ident
            self.type_string = type_string
            self.objectPool = objectPool
            self.retainCount = 1

        def retain(self, count=1):
            # print "%r.retain(%d)" % (self, count)
            self.retainCount += count
            return self

        def alloc(self):
            self.objectPool.base_alloc(self, self.ident)
            return self

        def dealloc(self):
            self.objectPool.base_dealloc(self, self.ident)
            self.retainCount = -1

        def release(self, count=1):
            # print "%r.release(%d)" % (self, count)
            newCount = self.retainCount - count
            # print "  newCount = %d" % (newCount,)
            if newCount == 0:
                self.dealloc()
            elif newCount < 0:
                raise ValueError(
                    "Reference %r over-released (%r -> %r)"
                    % (self, self.retainCount, newCount)
                )
            self.retainCount = newCount
            return self

        def autorelease(self):
            # print "%s.autorelease()" % (self,)
            self.objectPool.autorelease(self)
            return self

        def __repr__(self):
            return "%s(%r, %r)" % (type(self).__name__, self.ident, self.type_string)

    class RemoteObjectReference(BaseObjectReference):
        def __netrepr__(self):
            return "__obj__(%r)" % (self.ident,)

    class ObjectReference(BaseObjectReference):
        def __init__(self, objectPool, ident, type_string, obj, obj_id):
            BaseObjectReference.__init__(self, objectPool, ident, type_string)
            self.obj = obj
            self.obj_id = id(obj)

        def alloc(self):
            self = BaseObjectReference.alloc(self)
            self.objectPool.object_alloc(self, self.obj_id)
            return self

        def dealloc(self):
            self.objectPool.object_dealloc(self, self.obj_id)
            self.obj = None
            self.obj_id = -1
            BaseObjectReference.dealloc(self)

        def __netrepr__(self):
            return "__ref__(%r, %r)" % (self.ident, self.type_string)

    def test_netrepr():
        pool = ObjectPool()
        pool.push()
        netrepr = NetRepr(pool).netrepr
        assert netrepr("foo") == repr("foo")
        ref = pool.referenceForObject(object)
        assert ref.obj is object
        assert ref is pool.referenceForObject(object)
        assert ref.retainCount == 1
        refrepr = netrepr(ref)
        assert refrepr == netrepr(ref)
        ref.retain()
        assert ref.retainCount == 2
        pool.pop()
        pool.push()
        assert ref.retainCount == 1

        def __ref__(ident, type_string):
            return pool.referenceForIdent(ident)

        netref = eval(refrepr)
        assert netref is ref
        assert netref.obj is object
        ref.release()
        pool.pop()
        assert ref.obj is None

### remote_bootstrap.py

    __file__ = "<RemotePyInterpreterClient>"
    import sys

    # pool = ObjectPool()
    # netReprCenter = NetRepr(pool)
    # netrepr = netReprCenter.netrepr
    # netrepr_tuple = netReprCenter.netrepr_tuple
    # netrepr_list = netReprCenter.netrepr_list
    # netrepr_exception = netReprCenter.netrepr_exception
    namespace = globals()
    # namespace.update(pool.namespace)
    __main__ = sys.modules["__main__"]
    # assert namespace is not __main__.__dict__
    # pipe = RemotePipe(__runsocketcode__, __clientfile__, netReprCenter, namespace, pool)
    # interp = RemoteConsole(pipe, locals=__main__.__dict__)
    # interp.interact()

### remote_console.py

    import keyword
    import os
    import sys
    from code import InteractiveConsole, softspace

    try:
        import __builtin__
    except ImportError:
        import builtins as __builtin__

    class RemoteConsole(InteractiveConsole):
        def __init__(self, pipe, **kw):
            self.pipe = pipe
            self.buffer = None
            InteractiveConsole.__init__(self, **kw)
            self.locals["__interpreter__"] = self

        def raw_input(self, prompt=""):
            return self.pipe.expect("RemoteConsole.raw_input", prompt)

        def write(self, msg):
            return self.pipe.expect("RemoteConsole.write", msg)

        def resetbuffer(self):
            self.lastbuffer = self.buffer
            InteractiveConsole.resetbuffer(self)

        def displayhook(self, value):
            if value is not None:
                __builtin__._ = value
            return self.pipe.expect("RemoteConsole.displayhook", value)

        def excepthook(self, exc_type, value, traceback):
            return self.pipe.expect("RemoteConsole.excepthook", exc_type, value, traceback)

        def runcode(self, code):
            try:
                exec(code, self.locals)
            except SystemExit:
                raise
            except:  # noqa: E722, B001
                self.showtraceback()
            else:
                if softspace(sys.stdout, 0):
                    print

        def interact(self):
            old_raw_input = __builtin__.raw_input
            old_displayhook = sys.displayhook
            old_excepthook = sys.excepthook
            old_stdin = sys.stdin
            old_stdout = sys.stdout
            old_stderr = sys.stderr
            old_help = __builtin__.help
            old_quit = __builtin__.quit
            __builtin__.raw_input = self.raw_input
            __builtin__.help = "Close window to exit."
            __builtin__.quit = "Close window to exit."
            sys.displayhook = self.displayhook
            sys.excepthook = self.excepthook
            sys.stdin = self.pipe.stdin
            sys.stdout = self.pipe.stdout
            sys.stderr = self.pipe.stderr
            try:
                self.pipe.expect(
                    "RemoteConsole.initialize",
                    repr(sys.version_info),
                    sys.executable,
                    os.getpid(),
                )
                InteractiveConsole.interact(self)
            finally:
                __builtin__.raw_input = old_raw_input
                __builtin__.help = old_help
                __builtin__.quit = old_quit
                sys.displayhook = old_displayhook
                sys.excepthook = old_excepthook
                sys.stdin = old_stdin
                sys.stdout = old_stdout
                sys.stderr = old_stderr

        def recommendCompletionsFor(self, word):
            parts = word.split(".")
            if len(parts) > 1:
                # has a . so it must be a module or class or something
                # using eval, which shouldn't normally have side effects
                # unless there's descriptors/metaclasses doing some nasty
                # get magic
                objname = ".".join(parts[:-1])
                try:
                    obj = eval(objname, self.locals)
                except:  # noqa: E722, B001
                    return None, 0
                wordlower = parts[-1].lower()
                if wordlower == "":
                    # they just punched in a dot, so list all attributes
                    # that don't look private or special
                    prefix = ".".join(parts[-2:])
                    check = [
                        (prefix + _method)
                        for _method in dir(obj)
                        if _method[:1] != "_" and _method.lower().startswith(wordlower)
                    ]
                else:
                    # they started typing the method name
                    check = filter(lambda s: s.lower().startswith(wordlower), dir(obj))
            else:
                # no dots, must be in the normal namespaces.. no eval necessary
                check = set(dir(__builtin__))
                check.update(keyword.kwlist)
                check.update(self.locals)
                wordlower = parts[-1].lower()
                check = filter(lambda s: s.lower().startswith(wordlower), check)
            check.sort()
            return check, 0

### remote_pipe.py

    import itertools

    def as_unicode(s, encoding="utf-8"):
        typ = type(s)
        if typ is str:
            pass
        elif issubclass(typ, str):
            s = str(s)
        elif issubclass(typ, bytes):
            s = str(s, encoding, "replace")
        else:
            raise TypeError("expecting basestring, not %s" % (typ.__name__,))
        return s

    def as_str(s, encoding="utf-8"):
        typ = type(s)
        if typ is bytes:
            pass
        elif issubclass(typ, bytes):
            s = bytes(s)
        elif issubclass(typ, str):
            s = s.encode(encoding)
        else:
            raise TypeError("expecting basestring, not %s" % (typ.__name__,))
        return s

    class RemotePipe(object):
        def __init__(self, runcode, clientfile, netReprCenter, namespace, pool):
            self.runcode = runcode
            self.pool = pool
            self.clientfile = clientfile
            self.namespace = namespace
            self.result = self.namespace["__result__"] = {}
            self.netReprCenter = netReprCenter
            self.netrepr_list = netReprCenter.netrepr_list
            self.sequence = itertools.count()
            self.stdin = RemoteFileLike(self, "stdin")
            self.stdout = RemoteFileLike(self, "stdout")
            self.stderr = RemoteFileLike(self, "stderr")

        def send(self, *args):
            self.clientfile.write(self.netrepr_list(args) + "\n")
            self.clientfile.flush()

        def respond(self, *args):
            self.send("respond", *args)

        def expect(self, *args):
            self.pool.push()
            try:
                return self._expect(*args)
            finally:
                self.pool.pop()

        def _expect(self, *args):
            ident = next(self.sequence)
            self.send("expect", ident, *args)
            while ident not in self.result:
                self.runcode(self.clientfile, self.namespace)
            return self.result.pop(ident)

    class RemoteFileLike(object):
        softspace = 0
        closed = False
        encoding = "utf-8"

        def __init__(self, pipe, ident):
            self.pipe = pipe
            self.ident = ident

        def __iter__(self):
            while True:
                rval = self.readline()
                if not rval:
                    break
                yield rval

        def write(self, s):
            s = as_unicode(s, self.encoding)
            self.pipe.expect("RemoteFileLike.write", self.ident, s)

        def writelines(self, lines):
            for line in lines:
                self.write(line)

        def close(self):
            self.closed = True

        def flush(self):
            pass

        def isatty(self):
            return True

        def read(self, size=-1):
            return as_str(
                self.pipe.expect("RemoteFileLike.read", self.ident, size), self.encoding
            )

        def readline(self, size=-1):
            return as_str(
                self.pipe.expect("RemoteFileLike.readline", self.ident, size), self.encoding
            )

        def readlines(self):
            return list(self)

### setup.py

    """
    Script for building the example.

    Usage:
        python3 setup.py py2app
    """
    from setuptools import setup

    plist = {
        "CFBundleIdentifier": "net.sf.pyobjc.RemotePyInterpreter",
        "CFBundleDocumentTypes": [
            {
                "CFBundleTypeExtensions": ["RemotePyInterpreter", "*"],
                "CFBundleTypeName": "RemotePyInterpreter Session",
                "CFBundleTypeRole": "Editor",
                "NSDocumentClass": "RemotePyInterpreterDocument",
            }
        ],
    }

    REMOTE_REQUIREMENTS = [
        "tcpinterpreter",
        "netrepr",
        "remote_console",
        "remote_pipe",
        "remote_bootstrap",
    ]

    DATA_FILES = ["English.lproj"] + [(s + ".py") for s in REMOTE_REQUIREMENTS]

    setup(
        app=["RemotePyInterpreter.py"],
        data_files=DATA_FILES,
        options={"py2app": {"plist": plist}},
        setup_requires=["py2app", "pyobjc-framework-Cocoa"],
    )

### tcpinterpreter.py

    #! /usr/bin/env python

    """
        start socket based minimal readline exec server
    """
    import socket
    import sys

    def runsocketcode(clientfile, g):
        try:
            source = clientfile.readline().rstrip()
        except Exception:
            raise SystemExit
        if not source:
            raise SystemExit
        source = eval(source)
        co = compile(source + "\n", "<remote-source>", "exec")
        exec(co, g)

    def serveonce(clientsock, name="stdin"):
        clientfile = clientsock.makefile("r+b", 0)
        g = {
            "__name__": "__socketclient__",
            "__file__": "<%s>" % (name,),
            "__clientsock__": clientsock,
            "__clientfile__": clientfile,
            "__runsocketcode__": runsocketcode,
        }
        try:
            runsocketcode(clientfile, g)
        finally:
            clientfile.close()
            clientsock.close()

    def real_main():
        import sys

        hostport = eval(sys.argv[1])
        clientsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        clientsock.connect(hostport)
        serveonce(clientsock)

    def main():
        newglobals = {
            "__builtins__": sys.modules["__builtin__"],
            "__doc__": None,
            "__name__": "__main__",
        }
        sourcefile = __file__
        g = globals()
        g.clear()
        g.update(newglobals)
        serverglobals = {"__name__": "__socketclient__"}
        with open(sourcefile) as fp:
            sourcecode = fp.read()
        exec(sourcecode, serverglobals, serverglobals)

    if __name__ == "__main__":
        main()
    elif __name__ == "__socketclient__":
        real_main()

### test_client.py

    import fcntl
    import os
    import socket
    import sys
    from subprocess import PIPE, Popen

    from netrepr import NetRepr, RemoteObjectPool, RemoteObjectReference

    IMPORT_MODULES = ["netrepr", "remote_console", "remote_pipe", "remote_bootstrap"]
    source = []
    for fn in IMPORT_MODULES:
        for line in open(fn + ".py", "rU"):
            source.append(line)
        source.append("\n\n")
    SOURCE = repr("".join(source)) + "\n"

    def bind_and_listen(hostport):
        if isinstance(hostport, str):
            host, port = hostport.split(":")
            hostport = (host, int(port))
        serversock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        # set close-on-exec
        if hasattr(fcntl, "FD_CLOEXEC"):
            old = fcntl.fcntl(serversock.fileno(), fcntl.F_GETFD)
            fcntl.fcntl(serversock.fileno(), fcntl.F_SETFD, old | fcntl.FD_CLOEXEC)
        # allow the address to be re-used in a reasonable amount of time
        if os.name == "posix" and sys.platform != "cygwin":
            serversock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

        serversock.bind(hostport)
        serversock.listen(5)
        return serversock

    def open_connection(executable=sys.executable):
        serversock = bind_and_listen(("127.0.0.1", 0))
        hostport = serversock.getsockname()
        proc = Popen(
            [executable, "tcpinterpreter.py", repr(hostport)],
            stdin=PIPE,
            stdout=PIPE,
            stderr=PIPE,
            close_fds=True,
        )
        clientsock, address = serversock.accept()
        serversock.shutdown(2)
        return clientsock, proc

    def start_client(clientsock):
        f = clientsock.makefile("r+b", 0)
        f.write(SOURCE)
        f.flush()
        return f

    def client_loop(f):
        def writecode(code):
            # print('[code: %r]' % (code,))
            f.write(repr(code) + "\n")

        pool = RemoteObjectPool(writecode)
        netRepr = NetRepr(pool)
        netrepr = netRepr.netrepr

        def neteval(s):
            return eval(s, pool.namespace, pool.namespace)

        while True:
            code = f.readline().rstrip()
            pool.push()
            try:
                if not code:
                    break
                command = eval(code)
                basic = eval(command[0])
                if basic == "expect":
                    seq = eval(command[1])
                    name = eval(command[2])
                    args = map(neteval, command[3:])
                    code = None
                    rval = None
                    if name == "RemoteConsole.input":
                        try:
                            rval = input(*args)
                        except EOFError:
                            code = "raise EOFError"
                    elif name == "RemoteConsole.write":
                        sys.stdout.write(args[0])
                    elif name == "RemoteConsole.displayhook":
                        pass
                        obj = args[0]
                        if obj is None:
                            pass
                        elif isinstance(obj, RemoteObjectReference):
                            writecode('interp.write(repr(%s) + "\\n")' % (netrepr(obj),))
                        else:
                            print(repr(obj))
                    elif name.startswith("RemoteFileLike."):
                        fh = getattr(sys, args[0])
                        meth = getattr(fh, name[len("RemoteFileLike.") :])  # noqa: E203
                        rval = meth(*args[1:])
                    else:
                        print(name, args)
                    if code is None:
                        code = "__result__[%r] = %r" % (seq, rval)
                    writecode(code)
            finally:
                pool.pop()

    def main():
        clientsock, proc = open_connection()
        f = start_client(clientsock)
        try:
            client_loop(f)
        finally:
            f.close()
            clientsock.close()
            proc.stdin.close()
            print("[stdout]", proc.stdout.read())
            print("[stderr]", proc.stderr.read())

    if __name__ == "__main__":
        main()