[marcosdumay]

Prefixes are a problem, no arguing about that. But...

> is awkward to build (compared to just giving options to a command or arguments to a function)

Idiomatic bash: apt-get install package_name

Idiomátic haskell: apt_get $ AptInstall package_name

What is so awkward about that?

[mercurial]

First, it doesn't let you install multiple packages in one go (or let you install a specific package version). Secondly, it doesn't support apt-get options like -m, -d -n...

You could extend your argument structure for this, but then you need to specify every argument all the time, or have the user modify a default value. This is definitely awkward compared to straight shell.