I want to know if it is possible that I use strings without "".

If I type

Prelude>foo bar

which actually I mean

Prelude>foo "bar"

However I don't want to type ""s.

I have noticed if bar is predefined or it is a number, it can be used as arguments. But can other strings be used this way? Like in bash, we can use ping 127.0.0.1 where 127.0.0.1 is an argument.

If not, can foo be defined as a function so that it recognize arguments like bar as "bar"?

Thanks,

Yi Lu