gh-111201: A new Python REPL (GH-111567)

Co-authored-by: Łukasz Langa <lukasz@langa.pl>
Co-authored-by: Marta Gómez Macías <mgmacias@google.com>
Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>

Lib/_pyrepl/fancy_termios.py

@@ -0,0 +1,74 @@
+#   Copyright 2000-2004 Michael Hudson-Doyle <micahel@gmail.com>
+#
+#                        All Rights Reserved
+#
+#
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose is hereby granted without fee,
+# provided that the above copyright notice appear in all copies and
+# that both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
+# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
+# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+import termios
+
+
+class TermState:
+    def __init__(self, tuples):
+        (
+            self.iflag,
+            self.oflag,
+            self.cflag,
+            self.lflag,
+            self.ispeed,
+            self.ospeed,
+            self.cc,
+        ) = tuples
+
+    def as_list(self):
+        return [
+            self.iflag,
+            self.oflag,
+            self.cflag,
+            self.lflag,
+            self.ispeed,
+            self.ospeed,
+            self.cc,
+        ]
+
+    def copy(self):
+        return self.__class__(self.as_list())
+
+
+def tcgetattr(fd):
+    return TermState(termios.tcgetattr(fd))
+
+
+def tcsetattr(fd, when, attrs):
+    termios.tcsetattr(fd, when, attrs.as_list())
+
+
+class Term(TermState):
+    TS__init__ = TermState.__init__
+
+    def __init__(self, fd=0):
+        self.TS__init__(termios.tcgetattr(fd))
+        self.fd = fd
+        self.stack = []
+
+    def save(self):
+        self.stack.append(self.as_list())
+
+    def set(self, when=termios.TCSANOW):
+        termios.tcsetattr(self.fd, when, self.as_list())
+
+    def restore(self):
+        self.TS__init__(self.stack.pop())
+        self.set()