[svn r57321] merging the event branch:

* moving in test, misc, code, io directories and
  py/__init__.py
* py/bin/_find.py does not print to stderr anymore
* a few fixes to conftest files in other dirs
some more fixes and adjustments pending

--HG--
branch : trunk

py/misc/error.py

@@ -0,0 +1,79 @@
+
+import py
+import errno
+
+class Error(EnvironmentError):
+    __module__ = 'py.error'
+
+    def __repr__(self):
+        return "%s.%s %r: %s " %(self.__class__.__module__,
+                               self.__class__.__name__,
+                               self.__class__.__doc__,
+                               " ".join(map(str, self.args)),
+                               #repr(self.args)
+                                )
+
+    def __str__(self):
+        return "[%s]: %s" %(self.__class__.__doc__,
+                          " ".join(map(str, self.args)),
+                          )
+
+_winerrnomap = {
+    2: errno.ENOENT, 
+    3: errno.ENOENT, 
+    17: errno.EEXIST,
+    22: errno.ENOTDIR,
+    267: errno.ENOTDIR,
+    5: errno.EACCES,  # anything better?
+}
+# note: 'py.std' may not be imported yet at all, because 
+# the 'error' module in this file is imported very early.
+# This is dependent on dict order.
+
+ModuleType = type(py)
+
+class py_error(ModuleType):
+    """ py.error lazily provides higher level Exception classes
+        for each possible POSIX errno (as defined per
+        the 'errno' module.  All such Exceptions derive
+        from py.error.Error, which itself is a subclass
+        of EnvironmentError.
+    """
+    Error = Error
+
+    def _getwinerrnoclass(cls, eno): 
+        return cls._geterrnoclass(_winerrnomap[eno]) 
+    _getwinerrnoclass = classmethod(_getwinerrnoclass) 
+
+    def _geterrnoclass(eno, _errno2class = {}):
+        try:
+            return _errno2class[eno]
+        except KeyError:
+            clsname = py.std.errno.errorcode.get(eno, "UnknownErrno%d" %(eno,))
+            cls = type(Error)(clsname, (Error,),
+                    {'__module__':'py.error',
+                     '__doc__': py.std.os.strerror(eno)})
+            _errno2class[eno] = cls
+            return cls
+    _geterrnoclass = staticmethod(_geterrnoclass)
+
+    def __getattr__(self, name):
+        eno = getattr(py.std.errno, name)
+        cls = self._geterrnoclass(eno)
+        setattr(self, name, cls)
+        return cls
+
+    def getdict(self, done=[]):
+        try:
+            return done[0]
+        except IndexError:
+            for name in py.std.errno.errorcode.values():
+                hasattr(self, name)   # force attribute to be loaded, ignore errors
+            dictdescr = ModuleType.__dict__['__dict__']
+            done.append(dictdescr.__get__(self))
+            return done[0]
+
+    __dict__ = property(getdict)
+    del getdict
+
+error = py_error('py.error', py_error.__doc__)