If someone adds a function between func_before and func_after, and their coworker adds a different function also between func_before and func_after, you get a merge conflict because the line-based VCS doesn't know how the new functions should be ordered (or, potentially, interleaved ;) ). An AST-aware version control system could[1] realize that the order of function definitions is meaningless, and then wouldn't need to ask for help resolving the conflict.
[1] This isn't always true, so this might still involve some degree of being specialized-to-the-language. Or it might just mean that the AST the VCS worked with allows for fairly complicated types, and can distinguish between order-sensitive things and order-insensitive things.
Function definition order is certainly meaningful, at least to a human reader. Suppose co-worker 1's function is related to func_before, and co-worker 2's function is related to func_after, and the VCS flipped them around.
Or alternatively, I go in by myself and re-arrange the order of functions in a file to improve the clustering. If the VCS thinks the order of functions is meaningless, it won't recognize the change.
Comments
What kinds of problems you talking about.
One really obvious one is merge conflicts in the following pattern:
If someone adds a function between func_before and func_after, and their coworker adds a different function also between func_before and func_after, you get a merge conflict because the line-based VCS doesn't know how the new functions should be ordered (or, potentially, interleaved ;) ). An AST-aware version control system could[1] realize that the order of function definitions is meaningless, and then wouldn't need to ask for help resolving the conflict.[1] This isn't always true, so this might still involve some degree of being specialized-to-the-language. Or it might just mean that the AST the VCS worked with allows for fairly complicated types, and can distinguish between order-sensitive things and order-insensitive things.
Function definition order is certainly meaningful, at least to a human reader. Suppose co-worker 1's function is related to func_before, and co-worker 2's function is related to func_after, and the VCS flipped them around.
Or alternatively, I go in by myself and re-arrange the order of functions in a file to improve the clustering. If the VCS thinks the order of functions is meaningless, it won't recognize the change.