Add tuple support for IN

[ivanharvard]

Thanks ChatGPT!!!

To support syntax like:

(a, b).IN(...)

you’ll need to define a custom wrapper class that can represent a tuple of fields or expressions, and override its IN() method. Python’s built-in tuple won’t let you customize method resolution (like .IN(...)), so here’s how you can approach it:

---

Step 1: Define a TupleExpression class

class TupleExpression:
    def __init__(self, *elements):
        self.elements = elements  # list of Field, ColumnReference, Expression, etc.

    def IN(self, subquery_or_values):
        return Condition(self, "IN", subquery_or_values)

    def evaluate(self, db):
        # Return a list of evaluated tuples
        return [tuple(e.evaluate(db)) for e in self.elements]

---

Step 2: Provide a utility function or override __call__

You can make the tuple expression creation explicit:

TUPLE = lambda *args: TupleExpression(*args)

WHERE(TUPLE(emp.a, emp.b).IN(...))

Or, if you're comfortable overriding Python’s __getitem__ with a proxy object, you could do:

Query.db.TUPLE[emp.a, emp.b].IN(...)

But this is more complex and less idiomatic than using a helper like TUPLE(...).

---

Step 3: Modify Condition to support TupleExpression

Update the Condition class to allow left to be a TupleExpression and ensure evaluation logic accounts for that shape.

---

Summary

Python does not let you write (a, b).IN(...) directly with overridden behavior because (a, b) is a tuple and tuple has no .IN() method.

So you must wrap the tuple manually using:

WHERE(TUPLE(emp.a, emp.b).IN(...))

This is a clear, extensible pattern and allows proper evaluation of tuple comparisons (e.g., row-wise matching against subqueries or value sets).