I prefer [1,2,3,4].sum that you can get in ruby out of the box, but `1 2 3 4 sum` would look great too. Now if we want to handle compounded expression, you nee

I prefer [1,2,3,4].sum that you can get in ruby out of the box, but `1 2 3 4 sum` would look great too. Now if we want to handle compounded expression, you need either a given constant finite number of argument, or have a reserved word to mark grouping, much like `)`. A bit like stack based programming languages.