Update to Returns 0.15.0

Pipfile

@@ -10,7 +10,7 @@ pytest = "*"
 
 [packages]
 rx = "3.1.1"
-returns = "0.14.0"
+returns = "0.15.0"
 
 [requires]
 python_version = "3.8"

alleycat/reactive/functions.py

@@ -4,6 +4,7 @@
 import rx
 from mypy_extensions import VarArg
 from returns.context import RequiresContext
+from returns.iterables import Fold
 from returns.maybe import Maybe, Nothing
 from rx import Observable
 
@@ -25,12 +26,12 @@ def new_view(read_only=False) -> ReactiveView:
 
 
 def from_value(value: Optional[T], read_only=False) -> ReactiveProperty[T]:
-    return ReactiveProperty(Maybe.from_value(value), read_only)
+    return ReactiveProperty(Maybe.from_optional(value), read_only)
 
 
 def from_observable(value: Optional[Observable] = None, read_only=False) -> ReactiveView:
     init_value: RequiresContext[Observable, Any] = \
-        RequiresContext(lambda _: Maybe.from_value(value).value_or(rx.empty()))
+        RequiresContext(lambda _: Maybe.from_optional(value).value_or(rx.empty()))
 
     return ReactiveView(init_value, read_only)
 
@@ -47,7 +48,9 @@ def process(modifier: Callable[[VarArg(Observable)], Observable]):
         if modifier is None:
             raise ValueError("Argument 'modifier' is required.")
 
-        init_value = RequiresContext.from_iterable([v.context for v in values]).map(lambda v: modifier(*v))
+        # noinspection PyTypeChecker
+        init_value = Fold.collect([v.context for v in values], RequiresContext.from_value(())) \
+            .map(lambda v: modifier(*v))
 
         return ReactiveView(init_value)
 
@@ -73,8 +76,9 @@ def _combine_with(values: Sequence[ReactiveValue], combinator: Callable[[VarArg(
         raise ValueError("Argument 'values' is required.")
 
     def process(modifier: Callable[[Observable], Observable]):
-        init_value = RequiresContext.from_iterable([v.context for v in values]).map(
-            lambda v: combinator(*v)).map(modifier)
+        # noinspection PyTypeChecker
+        init_value = Fold.collect([v.context for v in values], RequiresContext.from_value(())) \
+            .map(lambda v: combinator(*v)).map(modifier)
 
         return ReactiveView(init_value)
 
@@ -95,7 +99,7 @@ def process():
         return process
 
     (target, key) = Maybe \
-        .from_value(name) \
+        .from_optional(name) \
         .map(lambda n: (obj, n)) \
         .or_else_call(infer_name(utils.get_property_reference, 3))
 

alleycat/reactive/property.py

@@ -3,9 +3,9 @@
 from typing import TypeVar, Generic, Callable, Optional, Any, cast, Tuple
 
 import rx
+from returns import pipeline
 from returns.functions import identity
 from returns.maybe import Maybe, Nothing
-from returns.pipeline import pipe as pipe_
 from rx import Observable
 from rx.subject import BehaviorSubject
 
@@ -47,7 +47,9 @@ def as_view(self) -> ReactiveView[T]:
 
     def pipe(self, modifiers: Callable[[Any], Tuple[Modifier, ...]]) -> ReactiveProperty:
         def stack(obj: Any):
-            return pipe_(*([self.modifier(obj)] + list(modifiers(obj))))
+            # FIXME: Not sure why both PyCharm and Mypy fails to resolve pipeline.pipe(). Should investigate later.
+            # noinspection PyUnresolvedReferences
+            return pipeline.pipe(*([self.modifier(obj)] + list(modifiers(obj))))  # type:ignore
 
         return ReactiveProperty(self.init_value, self.read_only, stack, self.validator)
 

alleycat/reactive/utils.py

@@ -16,9 +16,9 @@ def get_current_frame(depth: int = 1) -> Maybe[FrameType]:
         raise ValueError("Argument 'depth' must be zero or a positive integer.")
 
     def move_up(frame: Maybe[FrameType]) -> Maybe[FrameType]:
-        return frame.bind(lambda f: Maybe.from_value(f.f_back))
+        return frame.bind(lambda f: Maybe.from_optional(f.f_back))
 
-    return flow(Maybe.from_value(inspect.currentframe()), *[move_up for _ in range(depth)])  # type:ignore
+    return flow(Maybe.from_optional(inspect.currentframe()), *[move_up for _ in range(depth)])  # type:ignore
 
 
 def get_property_reference(frame: FrameType) -> Maybe[Tuple[Any, str]]:

alleycat/reactive/value.py

@@ -32,7 +32,7 @@ def __init__(self, read_only=False) -> None:
         self._name: Optional[str] = None
         self._read_only = read_only
 
-        data: RequiresContext[Any, ReactiveValue.Data[T]] = RequiresContext(lambda obj: self._get_data(obj))
+        data: RequiresContext[ReactiveValue.Data[T], Any] = RequiresContext(lambda obj: self._get_data(obj))
 
         # Declare separately to prevent an object allocation with every value/observable reference.
         self._context = data.map(lambda c: c.observable)
@@ -144,8 +144,7 @@ def __init__(self,
                      modifier: Callable[[Observable], Observable] = identity):
             assert observable is not None
 
-            self.name = Maybe.from_value(name)
-
+            self._name = Maybe.from_optional(name)
             self._value: Optional[U] = None
 
             self._initialized = False
@@ -163,6 +162,10 @@ def update(value):
             self._cancel_update = self.observable.subscribe(update, raise_exception)
             self._connection = self._observable.connect()  # type:ignore
 
+        @property
+        def name(self) -> Maybe[str]:
+            return self._name
+
         def label(self) -> str:
             return self.name.value_or("(anonymous)")
 
@@ -244,9 +247,8 @@ def init_data(v: Any):
             return partial(initialize, v, self.name, new_instance)
 
         return safe(getattr)(obj, DATA_KEY) \
-            .rescue(init_container) \
-            .bind(lambda v: safe(lambda: v[self.name])().rescue(init_data(v))) \
-            .fix(raise_exception) \
+            .lash(init_container) \
+            .bind(lambda v: safe(lambda: v[self.name])().lash(init_data(v))) \
             .unwrap()
 
     @abstractmethod

setup.py

@@ -13,7 +13,7 @@
     long_description_content_type="text/markdown",
     url="https://github.com/mysticfall/alleycat-reactive",
     packages=find_packages(),
-    install_requires=["returns==0.14.0", "rx==3.1.1"],
+    install_requires=["returns==0.15.0", "rx==3.1.1"],
     classifiers=[
         "Programming Language :: Python :: 3",
         "License :: OSI Approved :: MIT License",

tests/test_view.py

@@ -3,6 +3,7 @@
 
 import rx
 from returns.context import RequiresContext
+from returns.iterables import Fold
 from rx import operators as ops
 from rx.subject import BehaviorSubject
 
@@ -188,10 +189,11 @@ class Fixture:
 
             doubled: RV[int] = ReactiveView(value.context.map(lambda c: c.pipe(ops.map(lambda v: v * 2))))
 
-            result: RV[int] = ReactiveView(RequiresContext
-                                           .from_iterable([v.context for v in [value, doubled]])
-                                           .map(lambda v: rx.combine_latest(*v))
-                                           .map(lambda o: o.pipe(ops.map(lambda v: f"{v[0]} * 2 = {v[1]}"))))
+            # noinspection PyTypeChecker
+            result: RV[int] = ReactiveView(
+                Fold.collect([v.context for v in [value, doubled]], RequiresContext.from_value(()))
+                    .map(lambda v: rx.combine_latest(*v))
+                    .map(lambda o: o.pipe(ops.map(lambda v: f"{v[0]} * 2 = {v[1]}"))))
 
         fixture = Fixture()