[gentoo-commits] proj/R_overlay:master commit in: roverlay/util/

["André Erdmann" <dywi@mailerd.de>]

commit:     7739bc6f1809eabb3f034f50978e1e9f7d0c6c08
Author:     André Erdmann <dywi <AT> mailerd <DOT> de>
AuthorDate: Tue Sep  3 08:30:42 2013 +0000
Commit:     André Erdmann <dywi <AT> mailerd <DOT> de>
CommitDate: Tue Sep  3 08:30:42 2013 +0000
URL:        http://git.overlays.gentoo.org/gitweb/?p=proj/R_overlay.git;a=commit;h=7739bc6f

roverlay/util/counter

generates numbers in ascending order

---
 roverlay/util/counter.py | 68 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/roverlay/util/counter.py b/roverlay/util/counter.py
new file mode 100644
index 0000000..53fe631
--- /dev/null
+++ b/roverlay/util/counter.py
@@ -0,0 +1,68 @@
+# R overlay --
+# -*- coding: utf-8 -*-
+# Copyright (C) 2013 André Erdmann <dywi@mailerd.de>
+# Distributed under the terms of the GNU General Public License;
+# either version 2 of the License, or (at your option) any later version.
+
+try:
+   _LONG = long
+except NameError:
+   _LONG = int
+
+
+class CounterException ( Exception ):
+   pass
+# --- end of CounterException ---
+
+class CounterUnderflow ( CounterException ):
+   pass
+# --- end of CounterUnderflow ---
+
+
+class IDGenerator ( object ):
+
+   def __init__ ( self, first_value=0, use_long=False ):
+      super ( IDGenerator, self ).__init__()
+      self._initial_value = ( _LONG if use_long else int ) ( first_value - 1 )
+      self._current_value = self._initial_value
+   # --- end of __init__ (...) ---
+
+   def reset ( self ):
+      self._current_value = self._initial_value
+   # --- end of reset (...) ---
+
+   def inc ( self, step=1 ):
+      self._current_value += step
+      return self._current_value
+   # --- end of inc (...) ---
+
+   __next__ = inc
+
+   def peek ( self ):
+      val = self._current_value
+      if val == self._initial_value:
+         raise CounterException ( "no number generated so far!" )
+      elif val < self._initial_value:
+         raise CounterUnderflow()
+      else:
+         return val
+   # --- end of peek (...) ---
+
+   def __iter__ ( self ):
+      return self
+   # --- end of __iter__ (...) ---
+
+# --- end of IDGenerator ---
+
+class Counter ( IDGenerator ):
+
+   def dec ( self, step=1 ):
+      if self._current_value > self._initial_value:
+         self._current_value -= step
+         return self._current_value
+      else:
+         self._current_value = self._initial_value
+         raise CounterUnderflow()
+   # --- end of dec (...) ---
+
+# --- end of Counter ---