RAPL 3 - Reference Guide. - Phoenix Goucher

32 Data Types and Variables
Named Constants
It is frequently useful to be able to define a named constant in a program.
RAPL-3 provides a const keyword for this purpose. The format of a constant
definition is:
const identifier = value
Note that it is not necessary to specify a type for a const definition; the compiler
is able to deduce what type you are referring to by looking at the specified value.
Examples of const definitions are:
const x = 123 ;; an integer constant
const y = 10.3 ;; a floating point constant
const z = “hello” ;; a string constant
Only integer, floating point and string constants may be defined in this way. You
may use a named constant anywhere it would be legal to use the actual constant
itself. For example, if the following definitions are in your program, then this
section of code:
print(“hello”, 123, 10.3)
is exactly the same as this section of code:
print(z, x, y)
Typically, named constants are used for setting configurable values in a program.
For example, if a robot program rinses a dispense head some number of times in
between operations, one might have a const definition like this at the top of the
program:
const NUMBER_OF_RINSES = 3
This way the behaviour of the program can be changed by just changing the
constant, and code that refers to this number can use NUMBER_OF_RINSES,
which is much more obvious than just ‘3’.