67 add observable collections (#72)

* Add observable collections, which can be reduced to Values

* Add context manager to Variable, allowing setting it, but delaying notifying listeners
* Add ValuesObservable and ValuesEvent, which allows observing iterables, either as an Iterable or as each individual element
* Add VoidObservables, which can not be triggered and are instantiated as a singleton
* Allow Values to be derived with transforming function
* Allow deriving Observables from other Observables with a mapping function
* Allow Events to emit lazily, so values don't have to be instantiated if they are not observed

Author: FancyNeuron

src/spellbind/actions.py

@@ -146,10 +146,6 @@ def of(cls, value: bool) -> BoolConstant:
     def logical_not(self) -> BoolConstant:
         return BoolConstant.of(not self.value)
 
-    @property
-    def constant_value_or_raise(self) -> bool:
-        return self.value
-
 
 class BoolVariable(SimpleVariable[bool], BoolValue):
     pass

src/spellbind/bool_values.py

@@ -0,0 +1,29 @@
+from __future__ import annotations
+
+from abc import ABC, abstractmethod
+from typing import Iterable
+
+
+class Derived(ABC):
+    @property
+    @abstractmethod
+    def derived_from(self) -> frozenset[Derived]: ...
+
+    @property
+    def deep_derived_from(self) -> Iterable[Derived]:
+        found_derived = set()
+        derive_queue = [self]
+
+        while derive_queue:
+            current = derive_queue.pop(0)
+            for dependency in current.derived_from:
+                if dependency not in found_derived:
+                    found_derived.add(dependency)
+                    yield dependency
+                    derive_queue.append(dependency)
+
+    def is_derived_from(self, derived: Derived) -> bool:
+        for dependency in self.deep_derived_from:
+            if derived is dependency:
+                return True
+        return False

src/spellbind/deriveds.py

@@ -1,6 +1,5 @@
 from abc import ABC, abstractmethod
-from typing import TypeVar, Generic
-
+from typing import TypeVar, Generic, Iterable
 
 T = TypeVar("T")
 U = TypeVar("U")
@@ -14,7 +13,7 @@ def __call__(self) -> None: ...
 
 class ValueEmitter(Generic[T], ABC):
     @abstractmethod
-    def __call__(self, value0: T) -> None: ...
+    def __call__(self, value: T) -> None: ...
 
 
 class BiEmitter(Generic[T, U], ABC):
@@ -25,3 +24,8 @@ def __call__(self, value0: T, value1: U) -> None: ...
 class TriEmitter(Generic[T, U, S], ABC):
     @abstractmethod
     def __call__(self, value0: T, value1: U, value2: S) -> None: ...
+
+
+class ValuesEmitter(Generic[T], ABC):
+    @abstractmethod
+    def __call__(self, values: Iterable[T]) -> None: ...

src/spellbind/emitters.py

@@ -1,82 +1,60 @@
-from abc import ABC, abstractmethod
-from typing import Callable, TypeVar, Generic
+from typing import Callable, TypeVar, Generic, Iterable, Sequence
 
-from spellbind.emitters import Emitter, TriEmitter, BiEmitter, ValueEmitter
-from spellbind.functions import assert_parameter_max_count
+from spellbind.emitters import Emitter, TriEmitter, BiEmitter, ValueEmitter, ValuesEmitter
 from spellbind.observables import Observable, ValueObservable, BiObservable, TriObservable, Observer, \
-    ValueObserver, BiObserver, TriObserver, Subscription, WeakSubscription, StrongSubscription, \
-    RemoveSubscriptionError
+    ValueObserver, BiObserver, TriObserver, ValuesObserver, ValuesObservable, _BaseObservable, _BaseValuesObservable, \
+    _SingleBaseObservable
 
 _S = TypeVar("_S")
 _T = TypeVar("_T")
 _U = TypeVar("_U")
 _O = TypeVar('_O', bound=Callable)
 
 
-class _BaseEvent(Generic[_O], ABC):
-    _subscriptions: list[Subscription[_O]]
-
-    def __init__(self):
-        self._subscriptions = []
-
-    @abstractmethod
-    def _get_parameter_count(self) -> int: ...
-
-    def observe(self, observer: _O, times: int | None = None) -> None:
-        assert_parameter_max_count(observer, self._get_parameter_count())
-        self._subscriptions.append(StrongSubscription(observer, times))
-
-    def weak_observe(self, observer: _O, times: int | None = None) -> None:
-        assert_parameter_max_count(observer, self._get_parameter_count())
-        self._subscriptions.append(WeakSubscription(observer, times))
-
-    def unobserve(self, observer: _O) -> None:
-        for i, sub in enumerate(self._subscriptions):
-            if sub.matches_observer(observer):
-                del self._subscriptions[i]
-                return
-        raise ValueError(f"Observer {observer} is not subscribed to this event.")
-
-    def is_observed(self, observer: _O) -> bool:
-        return any(sub.matches_observer(observer) for sub in self._subscriptions)
-
-    def _emit(self, *args) -> None:
-        i = 0
-        while i < len(self._subscriptions):
-            try:
-                self._subscriptions[i](*args)
-                i += 1
-            except RemoveSubscriptionError:
-                del self._subscriptions[i]
-
-
-class Event(_BaseEvent[Observer], Observable, Emitter):
+class Event(_BaseObservable[Observer], Observable, Emitter):
     def _get_parameter_count(self) -> int:
         return 0
 
     def __call__(self) -> None:
-        self._emit()
+        self._emit_nothing()
 
 
-class ValueEvent(Generic[_S], _BaseEvent[Observer | ValueObserver[_S]], ValueObservable[_S], ValueEmitter[_S]):
+class ValueEvent(Generic[_S], _SingleBaseObservable[Observer | ValueObserver[_S]], ValueObservable[_S], ValueEmitter[_S]):
     def _get_parameter_count(self) -> int:
         return 1
 
     def __call__(self, value: _S) -> None:
-        self._emit(value)
+        self._emit_single(value)
 
+    def emit_lazy(self, func: Callable[[], _S]) -> None:
+        self._emit_single_lazy(func)
 
-class BiEvent(Generic[_S, _T], _BaseEvent[Observer | ValueObserver[_S] | BiObserver[_S, _T]], BiObservable[_S, _T], BiEmitter[_S, _T]):
+
+class BiEvent(Generic[_S, _T], _BaseObservable[Observer | ValueObserver[_S] | BiObserver[_S, _T]], BiObservable[_S, _T], BiEmitter[_S, _T]):
     def _get_parameter_count(self) -> int:
         return 2
 
     def __call__(self, value_0: _S, value_1: _T) -> None:
-        self._emit(value_0, value_1)
+        self._emit_n((value_0, value_1))
 
 
-class TriEvent(Generic[_S, _T, _U], _BaseEvent[Observer | ValueObserver[_S] | BiObserver[_S, _T] | TriObserver[_S, _T, _U]], TriObservable[_S, _T, _U], TriEmitter[_S, _T, _U]):
+class TriEvent(Generic[_S, _T, _U],
+               _BaseObservable[Observer | ValueObserver[_S] | BiObserver[_S, _T] | TriObserver[_S, _T, _U]],
+               TriObservable[_S, _T, _U],
+               TriEmitter[_S, _T, _U]):
     def _get_parameter_count(self) -> int:
         return 3
 
     def __call__(self, value_0: _S, value_1: _T, value_2: _U) -> None:
-        self._emit(value_0, value_1, value_2)
+        self._emit_n((value_0, value_1, value_2))
+
+
+class ValuesEvent(Generic[_S], _BaseValuesObservable[Observer | ValuesObserver[_S]], ValuesObservable[_S], ValuesEmitter[_S]):
+    def __call__(self, value: Iterable[_S]) -> None:
+        self._emit_single(value)
+
+    def emit_single(self, value: _S) -> None:
+        self._emit_single((value,))
+
+    def emit_lazy(self, func: Callable[[], Sequence[_S]]) -> None:
+        self._emit_single_lazy(func)

src/spellbind/event.py

@@ -23,11 +23,6 @@
 _U = TypeVar("_U")
 
 
-_COMMUTATIVE_OPERATORS = {
-    operator.add, sum, _multiply_all_floats, max, min
-}
-
-
 def _average_float(values: Sequence[float]) -> float:
     return sum(values) / len(values)
 
@@ -367,3 +362,6 @@ def __neg__(self) -> FloatValue:
 class CompareNumbersValues(TwoFloatsToOneValue[bool], BoolValue):
     def __init__(self, left: FloatLike, right: FloatLike, op: Callable[[float, float], bool]):
         super().__init__(op, left, right)
+
+
+ZERO = FloatConstant.of(0.)

src/spellbind/float_values.py

@@ -7,6 +7,11 @@ def _is_positional_parameter(param: Parameter) -> bool:
     return param.kind in (Parameter.POSITIONAL_ONLY, Parameter.POSITIONAL_OR_KEYWORD)
 
 
+def has_var_args(function: Callable) -> bool:
+    parameters = inspect.signature(function).parameters
+    return any(param.kind == Parameter.VAR_POSITIONAL for param in parameters.values())
+
+
 def count_positional_parameters(function: Callable) -> int:
     parameters = inspect.signature(function).parameters
     return sum(1 for parameter in parameters.values() if _is_positional_parameter(parameter))

src/spellbind/functions.py

@@ -0,0 +1,77 @@
+from __future__ import annotations
+
+import operator
+from abc import ABC, abstractmethod
+from functools import cached_property
+from typing import Iterable, Callable, Any
+
+from typing_extensions import TypeIs
+
+from spellbind.int_values import IntValue, IntConstant
+from spellbind.observable_collections import ObservableCollection, ReducedValue, CombinedValue, ValueCollection
+from spellbind.observable_sequences import ObservableList, _S, TypedValueList, ValueSequence, UnboxedValueSequence, \
+    ObservableSequence
+from spellbind.values import Value
+
+
+class ObservableIntCollection(ObservableCollection[int], ABC):
+    @property
+    def summed(self) -> IntValue:
+        return self.reduce_to_int(add_reducer=operator.add, remove_reducer=operator.sub, initial=0)
+
+    @property
+    def multiplied(self) -> IntValue:
+        return self.reduce_to_int(add_reducer=operator.mul, remove_reducer=operator.floordiv, initial=1)
+
+
+class ObservableIntSequence(ObservableSequence[int], ObservableIntCollection, ABC):
+    pass
+
+
+class ObservableIntList(ObservableList[int], ObservableIntSequence):
+    pass
+
+
+class IntValueCollection(ValueCollection[int], ABC):
+    @property
+    def summed(self) -> IntValue:
+        return self.unboxed.reduce_to_int(add_reducer=operator.add, remove_reducer=operator.sub, initial=0)
+
+    @property
+    @abstractmethod
+    def unboxed(self) -> ObservableIntCollection: ...
+
+
+class CombinedIntValue(CombinedValue[int], IntValue):
+    def __init__(self, collection: ObservableCollection[_S], combiner: Callable[[Iterable[_S]], int]):
+        super().__init__(collection=collection, combiner=combiner)
+
+
+class ReducedIntValue(ReducedValue[int], IntValue):
+    def __init__(self,
+                 collection: ObservableCollection[_S],
+                 add_reducer: Callable[[int, _S], int],
+                 remove_reducer: Callable[[int, _S], int],
+                 initial: int):
+        super().__init__(collection=collection,
+                         add_reducer=add_reducer,
+                         remove_reducer=remove_reducer,
+                         initial=initial)
+
+
+class UnboxedIntValueSequence(UnboxedValueSequence[int], ObservableIntSequence):
+    def __init__(self, sequence: IntValueSequence):
+        super().__init__(sequence)
+
+
+class IntValueSequence(ValueSequence[int], IntValueCollection, ABC):
+    @cached_property
+    def unboxed(self) -> ObservableIntSequence:
+        return UnboxedIntValueSequence(self)
+
+
+class IntValueList(TypedValueList[int], IntValueSequence):
+    def __init__(self, values: Iterable[int | Value[int]] | None = None):
+        def is_int(value: Any) -> TypeIs[int]:
+            return isinstance(value, int)
+        super().__init__(values, checker=is_int, constant_factory=IntConstant.of)

src/spellbind/int_collections.py

@@ -252,3 +252,6 @@ def __neg__(self) -> IntValue:
         if isinstance(of, IntValue):
             return of
         return super().__neg__()
+
+
+ZERO = IntConstant.of(0)