1. A method of generative programming; said method comprising: receiving a stochastic grammar defining variable parameters; generating a candidate program using said grammar; evaluating said candidate program in accordance with predetermined criteria; selectively repeating said generating and said evaluating; designating a particular candidate program as a modulating program responsive to evaluating; modifying a structure and a production probability of said grammar based upon a decomposition of terminal and non-terminal nodes of said modulating program; and focusing results of subsequent iterations of said generating in accordance with said modifying.