The model of compilation we introduced is essentially batch-oriented. In particular, it assumes that an entire source program has been written and that the program will be fully compiled before the programmer can execute the program or make any changes. An interesting and important alternative is an interactive compiler. An interactive compiler, usually part of an integrated program development environment, allows a programmer to interactively create and modify a program, fixing errors as they are detected. It also allows a program to be tested before it is fully written, thereby providing for stepwise implementation and testing. Redesign the compiler structure of Figure 1.3 to allow incremental compilation. (The key idea is to allow individual phases of a compiler to be run or rerun without necessarily doing a full compilation.)