Trac #29869: Move attrcall and friends from sage.misc.misc to new mod…

…ule sage.misc.call

This will help with #29865

URL: https://trac.sagemath.org/29869
Reported by: mkoeppe
Ticket author(s): Matthias Koeppe
Reviewer(s): Travis Scrimshaw

src/doc/en/reference/misc/index.rst

@@ -31,6 +31,7 @@ Special Base Classes, Decorators, etc.
    sage/misc/method_decorator
    sage/misc/object_multiplexer
    sage/misc/fast_methods
+   sage/misc/call
 
 Lists and Iteration, etc.
 ~~~~~~~~~~~~~~~~~~~~~~~~~

src/sage/categories/category_with_axiom.py

@@ -1660,7 +1660,7 @@ class ``Sets.Finite``), or in a separate file (typically in a class
 from sage.misc.cachefunc import cached_method, cached_function
 from sage.misc.lazy_attribute import lazy_class_attribute
 from sage.misc.lazy_import import LazyImport
-from sage.misc.misc import call_method
+from sage.misc.call import call_method
 from sage.categories.category import Category
 from sage.categories.category_singleton import Category_singleton
 from sage.categories.category_types import Category_over_base_ring

src/sage/categories/coxeter_groups.py

@@ -15,7 +15,7 @@
 from sage.misc.cachefunc import cached_method, cached_in_parent_method
 from sage.misc.lazy_import import LazyImport
 from sage.misc.constant_function import ConstantFunction
-from sage.misc.misc import attrcall
+from sage.misc.call import attrcall
 from sage.categories.category_singleton import Category_singleton
 from sage.categories.enumerated_sets import EnumeratedSets
 from sage.categories.finite_enumerated_sets import FiniteEnumeratedSets

src/sage/categories/finite_posets.py

@@ -1889,7 +1889,7 @@ def order_ideals_lattice(self, as_ideals=True, facade=None):
             if facade is None:
                 facade = self._is_facade
             if as_ideals:
-                from sage.misc.misc import attrcall
+                from sage.misc.call import attrcall
                 from sage.sets.set import Set
                 ideals = [Set(self.order_ideal(antichain))
                           for antichain in self.antichains()]

src/sage/categories/finite_semigroups.py

@@ -11,7 +11,7 @@
 # *****************************************************************************
 
 from sage.misc.cachefunc import cached_method
-from sage.misc.misc import attrcall
+from sage.misc.call import attrcall
 from sage.categories.category_with_axiom import CategoryWithAxiom
 
 

src/sage/combinat/root_system/root_lattice_realizations.py

@@ -14,7 +14,7 @@
 from __future__ import print_function, absolute_import
 
 from sage.misc.abstract_method import abstract_method, AbstractMethod
-from sage.misc.misc import attrcall
+from sage.misc.call import attrcall
 from sage.misc.cachefunc import cached_method, cached_in_parent_method
 from sage.misc.lazy_attribute import lazy_attribute
 from sage.misc.lazy_import import LazyImport

src/sage/combinat/root_system/type_dual.py

@@ -10,7 +10,7 @@
 # ****************************************************************************
 from __future__ import print_function, absolute_import
 
-from sage.misc.misc import attrcall
+from sage.misc.call import attrcall
 from sage.misc.cachefunc import cached_method
 from sage.misc.lazy_attribute import lazy_attribute
 from sage.combinat.root_system import cartan_type

src/sage/combinat/sf/sfa.py

@@ -662,7 +662,7 @@ def corresponding_basis_over(self, R):
                 put on a more robust and systematic footing.
             """
             from sage.combinat.sf.sf import SymmetricFunctions
-            from sage.misc.misc import attrcall
+            from sage.misc.call import attrcall
             try:
                 return attrcall(self._basis)(SymmetricFunctions(R))
             except AttributeError:   # or except (AttributeError, ValueError):

src/sage/geometry/hyperbolic_space/hyperbolic_coercion.py

@@ -27,7 +27,7 @@
 from sage.rings.infinity import infinity
 from sage.functions.other import real, imag, sqrt
 from sage.misc.lazy_import import lazy_import
-lazy_import('sage.misc.misc', 'attrcall')
+lazy_import('sage.misc.call', 'attrcall')
 
 class HyperbolicModelCoercion(Morphism):
     """

src/sage/matrix/matrix_symbolic_dense.pyx

@@ -772,7 +772,7 @@ cdef class Matrix_symbolic_dense(Matrix_generic_dense):
             [       x^2 + 2       -2*x + 3]
             [      -4*x + 6 x^2 - 6*x + 11]
         """
-        from sage.misc.misc import attrcall
+        from sage.misc.call import attrcall
         return self.apply_map(attrcall('expand'))
 
     def variables(self):

src/sage/misc/all.py

@@ -9,11 +9,13 @@
                   exists, forall, is_iterator,
                   random_sublist, walltime,
                   repr_lincomb,
-                  pad_zeros, attrcall,
+                  pad_zeros,
                   SAGE_DB, SAGE_TMP,
                    newton_method_sizes, compose,
                   nest)
 
+from .call import attrcall
+
 from .banner import version, banner
 
 from .temporary_file import tmp_dir, tmp_filename

src/sage/misc/call.py

@@ -0,0 +1,182 @@
+"""
+Attribute and method calling
+"""
+
+# ****************************************************************************
+#       Copyright (C) 2008 Mike Hansen
+#       Copyright (C) 2010, 2013 Nicolas M. Thiery
+#       Copyright (C) 2018 Frédéric Chapoton
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#                  https://www.gnu.org/licenses/
+# ****************************************************************************
+
+#############################################
+# Operators
+#############################################
+class AttrCallObject(object):
+    def __init__(self, name, args, kwds):
+        """
+        TESTS::
+
+            sage: f = attrcall('core', 3); f
+            *.core(3)
+            sage: TestSuite(f).run()
+        """
+        self.name = name
+        self.args = args
+        self.kwds = kwds
+
+    def __call__(self, x, *args):
+        """
+        Gets the ``self.name`` method from ``x``, calls it with
+        ``self.args`` and ``args`` as positional parameters and
+        ``self.kwds`` as keyword parameters, and returns the result.
+
+        EXAMPLES::
+
+            sage: core = attrcall('core', 3)
+            sage: core(Partition([4,2]))
+            [4, 2]
+
+            sage: series = attrcall('series', x)
+            sage: series(sin(x), 4)
+            1*x + (-1/6)*x^3 + Order(x^4)
+        """
+        return getattr(x, self.name)(*(self.args + args), **self.kwds)
+
+    def __repr__(self):
+        """
+        Return a string representation of this object.
+
+        The star in the output represents the object passed into ``self``.
+
+        EXAMPLES::
+
+            sage: attrcall('core', 3)
+            *.core(3)
+            sage: attrcall('hooks', flatten=True)
+            *.hooks(flatten=True)
+            sage: attrcall('hooks', 3, flatten=True)
+            *.hooks(3, flatten=True)
+        """
+        s = "*.%s(%s" % (self.name, ", ".join(map(repr, self.args)))
+        if self.kwds:
+            if self.args:
+                s += ", "
+            s += ", ".join("%s=%s" % keyvalue for keyvalue in self.kwds.items())
+        s += ")"
+        return s
+
+    def __eq__(self, other):
+        """
+        Equality testing
+
+        EXAMPLES::
+
+            sage: attrcall('core', 3, flatten = True) == attrcall('core', 3, flatten = True)
+            True
+            sage: attrcall('core', 2) == attrcall('core', 3)
+            False
+            sage: attrcall('core', 2) == 1
+            False
+        """
+        return self.__class__ == other.__class__ and self.__dict__ == other.__dict__
+
+    def __ne__(self, other):
+        """
+        Equality testing
+
+        EXAMPLES::
+
+            sage: attrcall('core', 3, flatten = True) != attrcall('core', 3, flatten = True)
+            False
+            sage: attrcall('core', 2) != attrcall('core', 3)
+            True
+            sage: attrcall('core', 2) != 1
+            True
+        """
+        return not self == other
+
+    def __hash__(self):
+        """
+        Hash value
+
+        This method tries to ensure that, when two ``attrcall``
+        objects are equal, they have the same hash value.
+
+        .. warning:: dicts are not hashable, so we instead hash their
+        items; however the order of those items might differ. The
+        proper fix would be to use a frozen dict for ``kwds``, when
+        frozen dicts will be available in Python.
+
+        EXAMPLES::
+
+            sage: x = attrcall('core', 3, flatten = True, blah = 1)
+            sage: hash(x)       # random # indirect doctest
+            210434060
+            sage: type(hash(x))
+            <type 'int'>
+            sage: y = attrcall('core', 3, blah = 1, flatten = True)
+            sage: hash(y) == hash(x)
+            True
+            sage: y = attrcall('core', 3, flatten = True, blah = 2)
+            sage: hash(y) != hash(x)
+            True
+            sage: hash(attrcall('core', 2)) != hash(attrcall('core', 3))
+            True
+            sage: hash(attrcall('core', 2)) != hash(1)
+            True
+
+        Note: a missing ``__hash__`` method here used to break the
+        unique representation of parents taking ``attrcall`` objects
+        as input; see :trac:`8911`.
+        """
+        return hash((self.args, tuple(sorted(self.kwds.items()))))
+
+
+def attrcall(name, *args, **kwds):
+    """
+    Returns a callable which takes in an object, gets the method named
+    name from that object, and calls it with the specified arguments
+    and keywords.
+
+    INPUT:
+
+     -  ``name`` - a string of the name of the method you
+        want to call
+
+     -  ``args, kwds`` - arguments and keywords to be passed
+        to the method
+
+    EXAMPLES::
+
+        sage: f = attrcall('core', 3); f
+        *.core(3)
+        sage: [f(p) for p in Partitions(5)]
+        [[2], [1, 1], [1, 1], [3, 1, 1], [2], [2], [1, 1]]
+    """
+    return AttrCallObject(name, args, kwds)
+
+
+def call_method(obj, name, *args, **kwds):
+    """
+    Call the method ``name`` on ``obj``.
+
+    This has to exist somewhere in Python!!!
+
+    .. SEEALSO:: :func:`operator.methodcaller` :func:`attrcal`
+
+    EXAMPLES::
+
+        sage: from sage.misc.call import call_method
+        sage: call_method(1, "__add__", 2)
+        3
+    """
+    return getattr(obj, name)(*args, **kwds)
+
+from sage.misc.persist import register_unpickle_override
+register_unpickle_override("sage.misc.misc", "call_method", call_method)