diff -r 000000000000 -r ca70ae20a155 src/extras/pyrepl/historical_reader.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/extras/pyrepl/historical_reader.py	Tue Feb 16 10:07:05 2010 +0530
@@ -0,0 +1,322 @@
+#   Copyright 2000-2004 Michael Hudson mwh@python.net
+#
+#                        All Rights Reserved
+#
+# Portions Copyright (c) 2005 Nokia Corporation 
+#
+# 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.
+
+from pyrepl import reader, commands
+from pyrepl.reader import Reader as R
+
+isearch_keymap = tuple(
+    [('\\%03o'%c, 'isearch-end') for c in range(256) if chr(c) != '\\'] + \
+    [(c, 'isearch-add-character')
+     for c in map(chr, range(32, 127)) if c != '\\'] + \
+    [('\\%03o'%c, 'isearch-add-character')
+     for c in range(256) if chr(c).isalpha() and chr(c) != '\\'] + \
+    [('\\\\', 'self-insert'),
+     (r'\C-r', 'isearch-backwards'),
+     (r'\C-s', 'isearch-forwards'),
+     (r'\C-c', 'isearch-cancel'),
+     (r'\C-g', 'isearch-cancel'),
+     (r'\<backspace>', 'isearch-backspace')])
+
+del c
+
+ISEARCH_DIRECTION_NONE = ''
+ISEARCH_DIRECTION_BACKWARDS = 'r'
+ISEARCH_DIRECTION_FORWARDS = 'f'
+
+class next_history(commands.Command):
+    def do(self):
+        r = self.reader
+        if r.historyi == len(r.history):
+            r.error("end of history list")
+            return
+        r.select_item(r.historyi + 1)
+
+class previous_history(commands.Command):
+    def do(self):
+        r = self.reader
+        if r.historyi == 0:
+            r.error("start of history list")
+            return
+        r.select_item(r.historyi - 1)
+
+class restore_history(commands.Command):
+    def do(self):
+        r = self.reader
+        if r.historyi != len(r.history):
+            if r.get_unicode() != r.history[r.historyi]:
+                r.buffer = list(r.history[r.historyi])
+                r.pos = len(r.buffer)
+                r.dirty = 1
+
+class first_history(commands.Command):
+    def do(self):
+        self.reader.select_item(0)
+
+class last_history(commands.Command):
+    def do(self):
+        self.reader.select_item(len(self.reader.history))
+
+class operate_and_get_next(commands.FinishCommand):
+    def do(self):
+        self.reader.next_history = self.reader.historyi + 1
+
+class yank_arg(commands.Command):
+    def do(self):
+        r = self.reader
+        if r.last_command is self.__class__:
+            r.yank_arg_i += 1
+        else:
+            r.yank_arg_i = 0
+        if r.historyi <= r.yank_arg_i:
+            r.error("beginning of history list")
+            return
+        a = r.get_arg(-1)
+        # XXX how to split?
+        words = r.get_item(r.historyi - r.yank_arg_i - 1).split()
+        if a < -len(words) or a >= len(words):
+            r.error("no such arg")
+            return
+        w = words[a]
+        b = r.buffer
+        if r.yank_arg_i > 0:
+            o = len(r.yank_arg_yanked)
+        else:
+            o = 0
+        b[r.pos - o:r.pos] = list(w)
+        r.yank_arg_yanked = w
+        r.pos += len(w) - o
+        r.dirty = 1
+
+class forward_history_isearch(commands.Command):
+    def do(self):
+        r = self.reader
+        r.isearch_direction = ISEARCH_DIRECTION_FORWARDS
+        r.isearch_start = r.historyi, r.pos
+        r.isearch_term = ''
+        r.dirty = 1
+        r.push_input_trans(r.isearch_trans)
+        
+
+class reverse_history_isearch(commands.Command):
+    def do(self):
+        r = self.reader
+        r.isearch_direction = ISEARCH_DIRECTION_BACKWARDS
+        r.dirty = 1
+        r.isearch_term = ''
+        r.push_input_trans(r.isearch_trans)
+        r.isearch_start = r.historyi, r.pos
+
+class isearch_cancel(commands.Command):
+    def do(self):
+        r = self.reader
+        r.isearch_direction = ISEARCH_DIRECTION_NONE
+        r.pop_input_trans()
+        r.select_item(r.isearch_start[0])
+        r.pos = r.isearch_start[1]
+        r.dirty = 1
+
+class isearch_add_character(commands.Command):
+    def do(self):
+        r = self.reader
+        b = r.buffer
+        r.isearch_term += self.event[-1]
+        r.dirty = 1
+        p = r.pos + len(r.isearch_term) - 1
+        if b[p:p+1] != [r.isearch_term[-1]]:
+            r.isearch_next()
+
+class isearch_backspace(commands.Command):
+    def do(self):
+        r = self.reader
+        if len(r.isearch_term) > 0:
+            r.isearch_term = r.isearch_term[:-1]
+            r.dirty = 1
+        else:
+            r.error("nothing to rubout")
+
+class isearch_forwards(commands.Command):
+    def do(self):
+        r = self.reader
+        r.isearch_direction = ISEARCH_DIRECTION_FORWARDS
+        r.isearch_next()
+
+class isearch_backwards(commands.Command):
+    def do(self):
+        r = self.reader
+        r.isearch_direction = ISEARCH_DIRECTION_BACKWARDS
+        r.isearch_next()
+
+class isearch_end(commands.Command):
+    def do(self):
+        r = self.reader
+        r.isearch_direction = ISEARCH_DIRECTION_NONE
+        r.console.forgetinput()
+        r.pop_input_trans()
+        r.dirty = 1
+        r.isearch_previous_term = r.isearch_term
+
+class HistoricalReader(R):
+    """Adds history support (with incremental history searching) to the
+    Reader class.
+
+    Adds the following instance variables:
+      * history:
+        a list of strings
+      * historyi:
+      * transient_history:
+      * next_history:
+      * isearch_direction, isearch_term, isearch_start:
+      * yank_arg_i, yank_arg_yanked:
+        used by the yank-arg command; not actually manipulated by any
+        HistoricalReader instance methods.
+    """
+
+    def collect_keymap(self):
+        return super(HistoricalReader, self).collect_keymap() + (
+            (r'\C-n', 'next-history'),
+            (r'\C-p', 'previous-history'),
+            (r'\C-o', 'operate-and-get-next'),
+            (r'\C-r', 'reverse-history-isearch'),
+            (r'\C-s', 'forward-history-isearch'),
+            (r'\M-r', 'restore-history'),
+            (r'\M-.', 'yank-arg'),
+            (r'\<page down>', 'last-history'),
+            (r'\<page up>', 'first-history'))
+
+
+    def __init__(self, console):
+        super(HistoricalReader, self).__init__(console)
+        self.history = []
+        self.historyi = 0
+        self.transient_history = {}
+        self.next_history = None
+        self.isearch_direction = ISEARCH_DIRECTION_NONE
+        self.isearch_previous_term = ''
+        for c in [next_history, previous_history, restore_history,
+                  first_history, last_history, yank_arg,
+                  forward_history_isearch, reverse_history_isearch,
+                  isearch_end, isearch_add_character, isearch_cancel,
+                  isearch_add_character, isearch_backspace,
+                  isearch_forwards, isearch_backwards, operate_and_get_next]:
+            self.commands[c.__name__] = c
+            self.commands[c.__name__.replace('_', '-')] = c
+        from pyrepl import input
+        self.isearch_trans = input.KeymapTranslator(
+            isearch_keymap, invalid_cls=isearch_end,
+            character_cls=isearch_add_character)
+        
+    def select_item(self, i):
+        self.transient_history[self.historyi] = self.get_unicode()
+        buf = self.transient_history.get(i)
+        if buf is None:
+            buf = self.history[i]
+        self.buffer = list(buf)
+        self.historyi = i
+        self.pos = len(self.buffer)
+        self.dirty = 1
+
+    def get_item(self, i):
+        assert i>=0 and i<=len(self.history)
+        if i < len(self.history):
+            return self.transient_history.get(i, self.history[i])
+        else:
+            return self.transient_history.get(i, self.get_unicode())
+
+    def prepare(self):
+        super(HistoricalReader, self).prepare()
+        try:
+            self.transient_history = {}
+            if self.next_history is not None \
+               and self.next_history < len(self.history):
+                self.historyi = self.next_history
+                self.buffer[:] = list(self.history[self.next_history])
+                self.pos = len(self.buffer)
+                self.transient_history[len(self.history)] = ''
+            else:
+                self.historyi = len(self.history)
+            self.next_history = None
+        except:
+            self.restore()
+            raise
+
+    def get_prompt(self, lineno, cursor_on_line):
+        if cursor_on_line and self.isearch_direction <> ISEARCH_DIRECTION_NONE:
+            d = 'rf'[self.isearch_direction == ISEARCH_DIRECTION_FORWARDS]
+            return "(%s-search `%s') "%(d, self.isearch_term)
+        else:
+            return super(HistoricalReader, self).get_prompt(lineno, cursor_on_line)
+
+    def isearch_next(self):
+        st = self.isearch_term
+        # If the isearch key is pressed twice without entering anything,
+        # try to use the previous search term, just like Emacs does it.
+        if st == '': 
+            self.isearch_term=st=self.isearch_previous_term
+            if st=='':
+                self.error("nothing to search")
+                return
+        p = self.pos
+        i = self.historyi
+        s = self.get_unicode()
+        forwards = self.isearch_direction == ISEARCH_DIRECTION_FORWARDS
+        while 1:
+            if forwards:
+                p = s.find(st, p + 1)
+            else:
+                p = s.rfind(st, 0, p + len(st) - 1)
+            if p != -1:
+                self.select_item(i)
+                self.pos = p
+                return
+            elif ((forwards and i >= len(self.history) - 1)
+                  or (not forwards and i == 0)):
+                self.error("not found")
+                return
+            else:
+                if forwards:
+                    i += 1
+                    s = self.get_item(i)
+                    p = -1
+                else:
+                    i -= 1
+                    s = self.get_item(i)
+                    p = len(s)
+
+    def finish(self):
+        super(HistoricalReader, self).finish()
+        ret = self.get_unicode()
+        for i, t in self.transient_history.items():
+            if i < len(self.history) and i != self.historyi:
+                self.history[i] = t
+        if ret:
+            self.history.append(ret)
+
+def test():
+    from pyrepl.unix_console import UnixConsole
+    reader = HistoricalReader(UnixConsole())
+    reader.ps1 = "h**> "
+    reader.ps2 = "h/*> "
+    reader.ps3 = "h|*> "
+    reader.ps4 = "h\*> "
+    while reader.readline():
+        pass
+
+if __name__=='__main__':
+    test()