_tobject.py

# Author: Enric Tejedor CERN  02/2019

################################################################################
# Copyright (C) 1995-2019, Rene Brun and Fons Rademakers.                      #
# All rights reserved.                                                         #
#                                                                              #
# For the licensing terms see $ROOTSYS/LICENSE.                                #
# For the list of contributors see $ROOTSYS/README/CREDITS.                    #
################################################################################

from ROOT.libROOTPythonizations import AddTObjectEqNePyz
import cppyy

# Searching


def _contains(self, o):
    # Relies on TObject::FindObject
    # Parameters:
    # - self: object where to search
    # - o: object to be searched in self
    # Returns:
    # - True if self contains o
    return bool(self.FindObject(o))


# Comparison operators


def _eq(self, o):
    import warnings

    warnings.warn(
        "\nTObject.__eq__ is deprecated and will be removed in ROOT 6.40."
        "\n\nIt forwards to TObject::Equals(), which uses pointer comparison if"
        " not overridden in derived classes."
        "\nThis may be confusing, because people expect value comparisons."
        "\nUse Pythons `is` for pointer comparison, or request/implement"
        " `operator==` on the C++ side if you need value-based equality checks.",
        FutureWarning,
        stacklevel=2,
    )
    return self._cpp_eq(o)


def _lt(self, o):
    if isinstance(o, cppyy.gbl.TObject):
        return self.Compare(o) == -1
    else:
        return NotImplemented


def _le(self, o):
    if isinstance(o, cppyy.gbl.TObject):
        return self.Compare(o) <= 0
    else:
        return NotImplemented


def _gt(self, o):
    if isinstance(o, cppyy.gbl.TObject):
        return self.Compare(o) == 1
    else:
        return NotImplemented


def _ge(self, o):
    if isinstance(o, cppyy.gbl.TObject):
        return self.Compare(o) >= 0
    else:
        return NotImplemented


def pythonize_tobject():
    klass = cppyy.gbl.TObject

    # Allow 'obj in container' syntax for searching
    klass.__contains__ = _contains

    # Inject comparison operators
    AddTObjectEqNePyz(klass)
    klass._cpp_eq = klass.__eq__
    klass.__eq__ = _eq
    klass.__lt__ = _lt
    klass.__le__ = _le
    klass.__gt__ = _gt
    klass.__ge__ = _ge


# Instant pythonization (executed at `import ROOT` time), no need of a
# decorator. This is a core class that is instantiated before cppyy's
# pythonization machinery is in place.
pythonize_tobject()