Should all operators be functions-that-return-functions?

[njlr]

To achieve a friendly syntax for operators with parameters, we use a pattern where the library provides a function-that-returns-a-function.

> seq.map
[Function]

> seq.map(x => x * 2)
[Function]

We do not do this for operators without parameters.

> seq.toArray
[Function]

Some operators have parameters, but each has a default value:

> seq.unique
[Function]

> seq.unique()
[Function]

This makes operator usage somewhat inconsistent:

[ 1, 2, 3 ]
  |> map(x => x * 2) // Parentheses to wrap parameters
  |> unique() // Parentheses required because we have default arguments
  |> toArray; // No parentheses, because this is not a function-that-returns-a-function

Perhaps it should look like this instead?

[ 1, 2, 3 ]
  |> map(x => x * 2) 
  |> unique() 
  |> toArray(); // Parentheses required for all operators