Remove deprecated trait types Function, Method, and Symbol (#1819)

This PR removes the long-deprecated trait types `Function`, `Method` and
`Symbol`.

Author: mdickinson

docs/source/traits_api_reference/trait_types.rst

@@ -115,12 +115,6 @@ Traits
 .. autoclass:: self
    :show-inheritance:
 
-.. autoclass:: Function
-   :show-inheritance:
-
-.. autoclass:: Method
-   :show-inheritance:
-
 .. autoclass:: Module
    :show-inheritance:
 
@@ -244,9 +238,6 @@ Traits
 .. autoclass:: Either
    :show-inheritance:
 
-.. autoclass:: Symbol
-   :show-inheritance:
-
 .. autoclass:: UUID
    :show-inheritance:
 

docs/source/traits_user_manual/defining.rst

@@ -264,7 +264,7 @@ the table.
 .. index:: CSet(), Constant(), Date(), Datetime(), Dict()
 .. index:: Directory(), Disallow, Either(), Enum()
 .. index:: Event(), Expression(), false, File()
-.. index:: Instance(), List(), Method(), Module()
+.. index:: Instance(), List(), Module()
 .. index:: Password(), Property(), Python()
 .. index:: PythonValue(), Range(), ReadOnly(), Regex()
 .. index:: Set() String(), This, Time()
@@ -333,8 +333,6 @@ the table.
 | File             | File([*value* = '', *filter* = None, *auto_set* = False, |
 |                  | *entries* = 10, *exists* = False,  \*\*\ *metadata*])    |
 +------------------+----------------------------------------------------------+
-| Function [3]_    | Function([*value* = None, \*\*\ *metadata*])             |
-+------------------+----------------------------------------------------------+
 | generic_trait    | n/a                                                      |
 +------------------+----------------------------------------------------------+
 | HTML             | HTML([*value* = '', *minlen* = 0,                        |
@@ -351,8 +349,6 @@ the table.
 +------------------+----------------------------------------------------------+
 | Map              | Map(*map*\ [, \*\*\ *metadata*])                         |
 +------------------+----------------------------------------------------------+
-| Method [3]_      | Method([\*\*\ *metadata*])                               |
-+------------------+----------------------------------------------------------+
 | Module           | Module([\*\*\ *metadata*])                               |
 +------------------+----------------------------------------------------------+
 | Password         | Password([*value* = '', *minlen* = 0, *maxlen* =         |
@@ -1055,16 +1051,8 @@ the metadata attribute::
 .. [2] The :class:`~.Either` trait type is likely to be deprecated at some
        point in the future. The :class:`~.Union` trait type should be preferred
        to :class:`~.Either` in new code.
-.. [3] The Function and Method trait types are now deprecated. See |Function|,
-       |Method|
 
 ..
    external urls
 
 .. _Traits bug tracker: https://github.com/enthought/traits/issues
-
-..
-   # substitutions
-
-.. |Function| replace:: :class:`~traits.trait_types.Function`
-.. |Method| replace:: :class:`~traits.trait_types.Method`

traits/api.py

@@ -72,8 +72,6 @@
     Callable,
     This,
     self,
-    Function,
-    Method,
     Module,
     Python,
     ReadOnly,
@@ -107,7 +105,6 @@
     Union,
     Type,
     Subclass,
-    Symbol,
     WeakRef,
     Date,
     Datetime,

traits/api.pyi

@@ -76,8 +76,6 @@ from .trait_types import (
     Callable as Callable,
     This as This,
     self as self,
-    Function as Function,
-    Method as Method,
     Module as Module,
     Python as Python,
     ReadOnly as ReadOnly,
@@ -111,7 +109,6 @@ from .trait_types import (
     Union as Union,
     Type as Type,
     Subclass as Subclass,
-    Symbol as Symbol,
     WeakRef as WeakRef,
     Date as Date,
     Datetime as Datetime,

traits/tests/test_trait_types.py

@@ -22,10 +22,7 @@
 from traits.api import (
     DefaultValue,
     Float,
-    Function,
-    Method,
     NoDefaultSpecified,
-    Symbol,
     TraitType,
     Undefined
 )
@@ -145,29 +142,3 @@ def __init__(self, default_value=NoDefaultSpecified, **metadata):
         self.assertEqual(ctrait.default_value_for(None, "dummy"), 81)
         cloned_ctrait = trait(30)
         self.assertEqual(cloned_ctrait.default_value_for(None, "dummy"), 30)
-
-
-class TestDeprecatedTraitTypes(unittest.TestCase):
-    def test_function_deprecated(self):
-        def some_function():
-            pass
-
-        with self.assertWarnsRegex(DeprecationWarning, "Function trait type"):
-            Function()
-        with self.assertWarnsRegex(DeprecationWarning, "Function trait type"):
-            Function(some_function, washable=True)
-
-    def test_method_deprecated(self):
-
-        class A:
-            def some_method(self):
-                pass
-
-        with self.assertWarnsRegex(DeprecationWarning, "Method trait type"):
-            Method()
-        with self.assertWarnsRegex(DeprecationWarning, "Method trait type"):
-            Method(A().some_method, gluten_free=False)
-
-    def test_symbol_deprecated(self):
-        with self.assertWarnsRegex(DeprecationWarning, "Symbol trait type"):
-            Symbol("random:random")

traits/trait_handlers.py

@@ -408,9 +408,8 @@ class TraitFunction(TraitHandler):
     """Ensures that assigned trait attribute values are acceptable to a
     specified validator function.
 
-    TraitFunction is the underlying handler for the predefined trait
-    **Function**, and for the use of function references as arguments to the
-    Trait() function.
+    TraitFunction is the underlying handler for the use of function references
+    as arguments to the Trait() function.
 
     The signature of the function must be of the form *function*(*object*,
     *name*, *value*). The function must verify that *value* is a legal value

traits/trait_types.py

@@ -19,7 +19,7 @@
 from os.path import isfile, isdir
 import re
 import sys
-from types import FunctionType, MethodType, ModuleType
+from types import ModuleType
 import uuid
 import warnings
 
@@ -35,7 +35,6 @@
     SequenceTypes,
     TypeTypes,
     Undefined,
-    TraitsCache,
     xgetattr,
 )
 from .trait_converters import trait_from, trait_cast
@@ -51,8 +50,6 @@
     Trait,
     _TraitMaker,
 )
-from .util.deprecated import deprecated
-from .util.import_symbol import import_symbol
 
 # TraitsUI integration imports
 from .editor_factories import (
@@ -980,64 +977,6 @@ class self(This):
     default_value_type = DefaultValue.object
 
 
-class Function(TraitType):
-    """ A trait type whose value must be a function.
-
-    .. deprecated:: 6.2.0
-        This trait type explicitly checks for an instance of
-        ``types.FunctionType``. For the majority of use cases, the more general
-        ``Callable`` trait type should be used instead. If an instance
-        specifically of ``types.FunctionType`` really is needed, one can use
-        ``Instance(types.FunctionType)``.
-    """
-
-    #: The default value type to use.
-    default_value_type = DefaultValue.constant
-
-    #: The default value for the trait type.
-    default_value = Undefined
-
-    @deprecated("Function trait type has been deprecated. Use 'Callable' or "
-                "'Instance(types.FunctionType)' instead")
-    def __init__(self, default_value=NoDefaultSpecified, **metadata):
-        super().__init__(default_value=default_value, **metadata)
-
-    #: The C-level fast validator to use:
-    fast_validate = (ValidateTrait.coerce, FunctionType)
-
-    #: A description of the type of value this trait accepts:
-    info_text = "a function"
-
-
-class Method(TraitType):
-    """ A trait type whose value must be a method.
-
-    .. deprecated:: 6.2.0
-        This trait type explicitly checks for an instance of
-        ``types.MethodType``. For the majority of use cases, the more general
-        ``Callable`` trait type should be used instead. If an instance
-        specifically of ``types.MethodType`` really is needed, one can use
-        ``Instance(types.MethodType)``.
-    """
-
-    #: The default value type to use.
-    default_value_type = DefaultValue.constant
-
-    #: The default value for the trait type.
-    default_value = Undefined
-
-    @deprecated("Method trait type has been deprecated. Use 'Callable' or "
-                "'Instance(types.MethodType)' instead")
-    def __init__(self, default_value=NoDefaultSpecified, **metadata):
-        super().__init__(default_value=default_value, **metadata)
-
-    #: The C-level fast validator to use:
-    fast_validate = (ValidateTrait.coerce, MethodType)
-
-    #: A description of the type of value this trait accepts:
-    info_text = "a method"
-
-
 class Module(TraitType):
     """ A trait type whose value must be a module.
     """
@@ -4271,79 +4210,6 @@ def get_editor(self, trait):
         return CompoundEditor(editors=editors)
 
 
-# -------------------------------------------------------------------------------
-#  'Symbol' trait:
-# -------------------------------------------------------------------------------
-class Symbol(TraitType):
-    """ A property trait type that refers to a Python object by name.
-
-    The value set to the trait must be a value of the form
-    ``'[package.package...package.]module[:symbol[([arg1,...,argn])]]'``
-    which is imported and evaluated to get underlying value.
-
-    The value returned by the trait is the actual object that this string
-    refers to.  The value is cached, so any calls are only evaluated once.
-
-    .. deprecated:: 6.3.0
-        This trait type is deprecated, and will be removed in a future
-        version of Traits.
-    """
-
-    @deprecated("The Symbol trait type has been deprecated.")
-    def __init__(self, default_value=NoDefaultSpecified, **metadata):
-        super().__init__(default_value=default_value, **metadata)
-
-    #: A description of the type of value this trait accepts:
-    info_text = (
-        "an object or a string of the form "
-        "'[package.package...package.]module[:symbol[([arg1,...,argn])]]' "
-        "specifying where to locate the object"
-    )
-
-    def get(self, object, name):
-        value = object.__dict__.get(name, Undefined)
-        if value is Undefined:
-            cache = TraitsCache + name
-            ref = object.__dict__.get(cache)
-            if ref is None:
-                object.__dict__[cache] = ref = object.trait(
-                    name
-                ).default_value_for(object, name)
-
-            if isinstance(ref, str):
-                object.__dict__[name] = value = self._resolve(ref)
-
-        return value
-
-    def set(self, object, name, value):
-        dict = object.__dict__
-        old = dict.get(name, Undefined)
-        if isinstance(value, str):
-            dict.pop(name, None)
-            dict[TraitsCache + name] = value
-            object.trait_property_changed(name, old)
-        else:
-            dict[name] = value
-            object.trait_property_changed(name, old, value)
-
-    def _resolve(self, ref):
-        try:
-            elements = ref.split("(", 1)
-            symbol = import_symbol(elements[0])
-            if len(elements) == 1:
-                return symbol
-
-            args = eval("(" + elements[1])
-            if not isinstance(args, tuple):
-                args = (args,)
-
-            return symbol(*args)
-        except Exception:
-            raise TraitError(
-                "Could not resolve '%s' into a valid symbol." % ref
-            )
-
-
 class UUID(TraitType):
     """ A read-only trait type whose value is a globally unique UUID (type 4).
 

traits/trait_types.pyi

@@ -250,14 +250,6 @@ class self(This):
     ...
 
 
-class Function(_TraitType[_OptionalCallable, _OptionalCallable]):
-    ...
-
-
-class Method(_TraitType[_OptionalCallable, _OptionalCallable]):
-    ...
-
-
 class Module(_TraitType[_Any, _Any]):
     ...
 
@@ -597,10 +589,6 @@ class Union(_TraitType[_Any, _Any]):
         ...
 
 
-class Symbol(_TraitType[_Any, _Any]):
-    ...
-
-
 class UUID(_TraitType[_Union[str, _UUID], _UUID]):
     def __init__(
         self,