Side-effect removal transformation

A side-effect is any change in program state that occurs as a by-product of the evaluation of an expression. Side-effects are often thought to impede program comprehension and to lead to complex, poorly understood and occasionally undefined semantics. Side-effect removal transformation (SERT) improves comprehension by rewriting a program p, which may contain side-effects, into a semantically equivalent program p', which is guaranteed to be side-effect free. This paper introduces the SERT approach to the side-effect problem, briefly reporting initial experience with an implementation of SERT for C programs, called Linsert.