[mightybyte]

It's going to be difficult for something like this to match the ease of shell scripting. For instance, typing `cd "foo"` is significantly more painful than `cd foo`. (Maybe this could be fixed by forking or adding to ghci so that when you hit space after the function name it automatically puts the quotes in for you and places the cursor between them.) Options are certainly important, and as others have said, they can be emulated with records. Is the syntax going to just as convenient as shell scripting? No. But that's not the point. The point is that shell scripting is massively painful in a lot of other ways where Haskell blows it away. So the task is to find a happy medium that gets fairly close to the convenience of shell scripting while still giving us the power of Haskell.

There are a number of potential approaches for coming close to the ease of shell scripting. One is options records as others have mentioned. For defaults you can have a Default instance (no, that's not boilerplate because you would have had to specify the defaults somewhere anyway). Then there is plenty of room for infix operator combinators to make it easier to change individual options. A second option could be to put options into a string that would get parsed into a record. You could use patterns similar to those used in existing command line argument processors like optparse-applicative. Or, if you don't like that, then maybe a quasiquote could give more power.

Do these things require some boilerplate? Yes. We know that is going to be required since Haskell wasn't designed for the convenience that shells were designed for. But that's fine in this case because the potential benefits are huge.