Well, you could choose to abort rather than skip anything. The problem is that impure code can do dangerous things (depending on which i/o primitives are provi

Well, you could choose to abort rather than skip anything. The problem is that impure code can do dangerous things (depending on which i/o primitives are provided). For example, a macro might create and delete a bunch of temporary files; this might work fine in one scenario (e.g. during compilation) but misbehave during another (e.g. static analysis). In which case "static analysis" would no longer be static.