Node:Prefix and postfix functions, Next:Function definition syntax, Up:Functions
A prefix function can take any number of parameters specified after the function name:
:(F :x1 :x2)=x1-x2 # Definition of function F. F 10 3 # Call of function F; yields 7.
A postfix function takes a single parameter specified before the function name:
:(:arg G)=arg*arg # Definition of function G. 5 G # Call of function G; yields 25.
It is also possible for a function to take parameters specified both before and after the function name. This allows infix functions:
:(:x mod :y) = x - y*floor(x/y) -8 mod 3 # Yields 1.The arguments before the function name are called the left parameters, while those after are called the right parameters. In the
mod example, x is a left parameter, and
y is a right parameter.
Having both prefix and postfix functions could lead to ambiguity. See <not written> on the details.