It's impossible to pass around functions without arguments in Haskell, because there are no functions without arguments in
Haskell. It looks like the same is true of Gluon. (So you don't really pass around the function name: you pass around the variable which contains the result of evaluating the expression.)
In languages where there can be functions with no arguments, if referring to the function without parentheses calls it, it can be inconvenient to get a reference to the function itself.
In languages where there can be functions with no arguments, if referring to the function without parentheses calls it, it can be inconvenient to get a reference to the function itself.