A simplistic stack-based calculator. No datatypes, even.

The vertical bar "|" separates items on the stack - you can read the functions as though this were parentheses (like @functions) or comma (separating a function's arguments).

The stack is evaluated from right to left, but for these simple functions I thought it would be more natural to read in a left-to-right order.

Some to try:
@right|value|3 => "lue"
@right|value|a => "lue"
@add|6|4 => "10"
@sum|1|2|3|4|5|6 => "21" (greedy, uses up the whole stack)
@if|true|one|two => "one"
@right|value|@if|false|3|4 => "alue"