Propeller Manual

2: Spin Language Reference – PRI
PRI
Designator: Declare a Private Method Block.
((PUB ┆ PRI))
PRI Name 〈(Param 〈, Param〉…)〉 〈:RValue〉 〈| LocalVar 〈[Count]〉〉 〈,LocalVar 〈[Count]〉〉…
SourceCodeStatements
• Name is the desired name for the private method.
•
Param is a parameter name (optional). Methods can contain zero or more comma-
delimited parameters, enclosed in parentheses. Param must be globally unique, but
other methods may also use the same symbol name. Each parameter is essentially a
long variable and can be treated as such.
•
RValue is a name for the return value of the method (optional). This becomes an alias
to the method’s built-in
RESULT variable. RValue must be globally unique, but other
methods may also use the same symbol name. The RValue (and/or
RESULT variable)
is initialized to zero (0) upon each call to the method.
•
LocalVar is a name for a local variable (optional). LocalVar must be globally unique,
but other methods may also use the same symbol name. All local variables are of
size long (four bytes) and are left uninitialized upon each call to the method.
Methods can contain zero or more comma-delimited local variables.
•
Count is an optional expression, enclosed in brackets, that indicates this is a local
array variable, with Count number of elements; each being a long in size. When later
referencing these elements, they begin with element 0 and end with element Count-1.
•
SourceCodeStatements is one or more lines of executable source code, indented by at
least one space, that perform the function of the method.
Explanation
PRI is the Private Method Block declaration. A Private Method is a section of source code
that performs a specific function then returns a result value. This is one of six special
declarations (
CON, VAR, OBJ, PUB, PRI, and DAT) that provide inherent structure to the Spin
language.
Every object can contain a number of private (
PRI) and public (PUB) methods. Private
methods can only be accessed from inside of the object and serve to perform vital, protected
functions, for the object. Private methods are like Public methods in every way except that
they are declared with
PRI, instead of PUB, and are not accessible from outside the object.
Please see
PUB, Page 182, for more information.
Propeller Manual v1.1 · Page 181