  In this paper, we introduce and analyze a new switch operator for the
six-vertex model. This operator, derived from the Yang-Baxter equation, allows
us to express the partition function with arbitrary boundaries in terms of a
base case with domain wall boundary conditions. As an application, we derive
explicit formulas for the factorial Schur functions and their generalizations.
Our results provide new insights into the relationship between boundary
conditions and partition functions in the six-vertex model.
