Chapter 5. Making New Functions

Function in Ripley are just executable arrays that have been assigned as elements in the user dictionary. To define a function we use an executable array and the 'def' operator that we used in the variable assignment section from before. Here is an example where I create a function that prints "Hello World!":

Example 5-1. Hello World function

/hello { "Hello World!" print } def

Arguments to functions are implemented using the operand stack, just like every other Ripley function. Here is an example add10 function, which adds 10 to whatever you give it:

Example 5-2. Add 10 function

/add10 { 10 add } def
20 add10 print
100 add10 print