The whole point of programming is to get exact results by solving all edge cases. Machine learning/Neural nets are only good at guessing results, and cannot solve all edge cases without specific direction.
This is what programming already is, the "pattern" being code. A compiler is a program that looks at a code pattern and, if it's a good compiler, it can tell you if you've missed edge-cases through compile time errors.
A program that looks at a pattern, emulates it and then enumerates the various edge-cases, looking for further patterns from the programmer's answer.
It would still require effort but it could be a lot easier than present approaches and it might even find edge-cases a human would miss.