samredai commented on code in PR #4466:
URL: https://github.com/apache/iceberg/pull/4466#discussion_r851553371
##########
python/src/iceberg/expressions/base.py:
##########
@@ -122,3 +125,139 @@ def __le__(self, other):
def __ge__(self, other):
return self.value >= other.value
+
+
+class BooleanExpression(ABC):
+ """base class for all boolean expressions"""
+
+ @abstractmethod
+ def __invert__(self) -> "BooleanExpression":
+ ...
+
+
+class And(BooleanExpression):
+ """AND operation expression - logical conjunction"""
+
+ def __new__(cls, left: BooleanExpression, right: BooleanExpression, *rest:
BooleanExpression):
+ if rest:
+ return reduce(And, (left, right, *rest))
+ if left is AlwaysFalse() or right is AlwaysFalse():
+ return AlwaysFalse()
+ elif left is AlwaysTrue():
+ return right
+ elif right is AlwaysTrue():
+ return left
+ return super().__new__(cls)
+
+ def __init__(
+ self,
+ left: BooleanExpression,
+ right: BooleanExpression,
+ *rest: BooleanExpression,
+ ):
+ if not rest:
+ self.left = left
+ self.right = right
Review Comment:
I do think this could use some doc-strings describing this behavior though.
Specifically mentioning \_\_new\_\_
```
"""AND operation expression - logical conjunction
Args:
left(BooleanExpression): The left hand boolean expression
right(BooleanExpression): The right hand boolean expression
*rest(BooleanExpression): Additional boolean expressions to fold
into the AND expression
Note:
Additional boolean expressions provided to `rest` will be
folded/reduced to create an object
with only `left` and `right` specified (see the `__new__`
constructor) . For example,
And(a, b, c) wil result in the equivalent of And(And(a, b), c).
"""
```
Once predicates are added we could include an `Example:` section here too
without failing the pydoc tests.
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