Function FindBinaryOverload

pkg/sql/sem/tree/typing.go:28–51

FindBinaryOverload finds the correct type signature overload for the specified binary operator, given the types of its inputs. If an overload is found, FindBinaryOverload returns true, plus a pointer to the overload. If an overload is not found, FindBinaryOverload returns false.

(
	bin treebin.BinaryOperatorSymbol, leftType, rightType *types.T,
)

// found, FindBinaryOverload returns true, plus a pointer to the overload.
// If an overload is not found, FindBinaryOverload returns false.
func FindBinaryOverload(
	bin treebin.BinaryOperatorSymbol, leftType, rightType *types.T,
) (ret *BinOp, ok bool) {

	// Find the binary op that matches the type of the expression's left and
	// right children. No more than one match should ever be found. The
	// TestTypingBinaryAssumptions test ensures this will be the case even if
	// new operators or overloads are added.
	_ = BinOps[bin].ForEachBinOp(func(o *BinOp) error {
		if leftType.Family() == types.UnknownFamily {
			ok = rightType.Equivalent(o.RightType)
		} else if rightType.Family() == types.UnknownFamily {
			ok = leftType.Equivalent(o.LeftType)
		} else {
			ok = leftType.Equivalent(o.LeftType) && rightType.Equivalent(o.RightType)
		}
		if !ok {
			return nil
		}
		ret = o
		return iterutil.StopIteration()
	})
	return ret, ok
}