In the context of functional programming, semantic methods are commonly used to drive program transformations. However, classical semantic domains often rely on recursive objects which embed the control flow of recursive functions. As a consequence, transformations which have to modify the control flow are difficult to define. We propose in this paper a new semantic domain where the control flow is defined implicitly, and thus can be modified. This new theoretical and practical framework allows to homogeneously define and extend powerful transformations related to partial evaluation and deforestation.