Initial revision

1 files changed, 152 insertions, 0 deletions

diff --git a/deferred_operand.py b/deferred_operand.py
new file mode 100644
index 0000000..f2af66c
--- /dev/null
+++ b/deferred_operand.py
@@ -0,0 +1,152 @@
+#!/usr/bin/env python3
+
+from abc import ABC, abstractmethod
+from typing import Any, Generic, TypeVar
+
+T = TypeVar('T')
+
+
+class DeferredOperand(ABC, Generic[T]):
+    """A wrapper around an operand whose value is deferred until it is
+    needed.  See subclass SmartFuture for an example usage.
+    """
+
+    @abstractmethod
+    def _resolve(self) -> T:
+        pass
+
+    @staticmethod
+    def resolve(x: Any) -> Any:
+        while isinstance(x, DeferredOperand):
+            x = x._resolve()
+        return x
+
+    def __lt__(self, other: Any) -> bool:
+        return DeferredOperand.resolve(self) < DeferredOperand.resolve(other)
+
+    def __le__(self, other: Any) -> bool:
+        return DeferredOperand.resolve(self) <= DeferredOperand.resolve(other)
+
+    def __eq__(self, other: Any) -> bool:
+        return DeferredOperand.resolve(self) == DeferredOperand.resolve(other)
+
+    def __ne__(self, other: Any) -> bool:
+        return DeferredOperand.resolve(self) != DeferredOperand.resolve(other)
+
+    def __gt__(self, other: Any) -> bool:
+        return DeferredOperand.resolve(self) > DeferredOperand.resolve(other)
+
+    def __ge__(self, other: Any) -> bool:
+        return DeferredOperand.resolve(self) >= DeferredOperand.resolve(other)
+
+    def __not__(self) -> bool:
+        return not DeferredOperand.resolve(self)
+
+    def bool(self) -> bool:
+        return DeferredOperand.resolve(self)
+
+    def __add__(self, other: Any) -> T:
+        return DeferredOperand.resolve(self) + DeferredOperand.resolve(other)
+
+    def __iadd__(self, other: Any) -> T:
+        return DeferredOperand.resolve(self) + DeferredOperand.resolve(other)
+
+    def __radd__(self, other: Any) -> T:
+        return DeferredOperand.resolve(self) + DeferredOperand.resolve(other)
+
+    def __sub__(self, other: Any) -> T:
+        return DeferredOperand.resolve(self) - DeferredOperand.resolve(other)
+
+    def __mul__(self, other: Any) -> T:
+        return DeferredOperand.resolve(self) * DeferredOperand.resolve(other)
+
+    def __pow__(self, other: Any) -> T:
+        return DeferredOperand.resolve(self) ** DeferredOperand.resolve(other)
+
+    def __truediv__(self, other: Any) -> Any:
+        return DeferredOperand.resolve(self) / DeferredOperand.resolve(other)
+
+    def __floordiv__(self, other: Any) -> T:
+        return DeferredOperand.resolve(self) // DeferredOperand.resolve(other)
+
+    def __contains__(self, other):
+        return DeferredOperand.resolve(other) in DeferredOperand.resolve(self)
+
+    def and_(self, other):
+        return DeferredOperand.resolve(self) & DeferredOperand.resolve(other)
+
+    def or_(self, other):
+        return DeferredOperand.resolve(self) & DeferredOperand.resolve(other)
+
+    def xor(self, other):
+        return DeferredOperand.resolve(self) & DeferredOperand.resolve(other)
+
+    def invert(self):
+        return ~(DeferredOperand.resolve(self))
+
+    def is_(self, other):
+        return DeferredOperand.resolve(self) is DeferredOperand.resolve(other)
+
+    def is_not(self, other):
+        return DeferredOperand.resolve(self) is not DeferredOperand.resolve(other)
+
+    def __abs__(self):
+        return abs(DeferredOperand.resolve(self))
+
+    def setitem(self, k, v):
+        DeferredOperand.resolve(self)[DeferredOperand.resolve(k)] = v
+
+    def delitem(self, k):
+        del DeferredOperand.resolve(self)[DeferredOperand.resolve(k)]
+
+    def getitem(self, k):
+        return DeferredOperand.resolve(self)[DeferredOperand.resolve(k)]
+
+    def lshift(self, other):
+        return DeferredOperand.resolve(self) << DeferredOperand.resolve(other)
+
+    def rshift(self, other):
+        return DeferredOperand.resolve(self) >> DeferredOperand.resolve(other)
+
+    def mod(self, other):
+        return DeferredOperand.resolve(self) % DeferredOperand.resolve(other)
+
+    def matmul(self, other):
+        return DeferredOperand.resolve(self) @ DeferredOperand.resolve(other)
+
+    def neg(self):
+        return -(DeferredOperand.resolve(self))
+
+    def pos(self):
+        return +(DeferredOperand.resolve(self))
+
+    def truth(self):
+        return DeferredOperand.resolve(self)
+
+    def __hash__(self):
+        return DeferredOperand.resolve(self).__hash__()
+
+    def __call__(self):
+        return DeferredOperand.resolve(self)()
+
+    def __iter__(self):
+        return DeferredOperand.resolve(self).__iter__()
+
+    def __repr__(self) -> str:
+        return DeferredOperand.resolve(self).__repr__()
+
+    def __bytes__(self) -> bytes:
+        return DeferredOperand.resolve(self).__bytes__()
+
+    def __int__(self) -> int:
+        return int(DeferredOperand.resolve(self))
+
+    def __float__(self) -> float:
+        return float(DeferredOperand.resolve(self))
+
+    def __getattr__(self, method_name):
+        def method(*args, **kwargs):
+            return getattr(DeferredOperand.resolve(self), method_name)(
+                *args, **kwargs
+            )
+        return method